To understand why your energy bill shoots up when you use an air conditioner on hot summer days, we need to look at the physics behind cooling the humid air in your home. There is simply a big difference between cooling dry air and cooling humid air.

Scenario 1: Cooling dry air

This scenario is the ideal situation. When the air in your home has a healthy humidity level, between 40% and 60%, an air conditioner can do its job quickly and thus cool the air rapidly. Dry air has a low heat capacity, as it does not retain heat as well. As soon as you switch on the air conditioner, the unit simply needs to lower the temperature of the air – a process also known as ‘sensible cooling’. The air conditioner reaches the desired temperature within a few minutes. As a result, it consumes a minimal amount of electricity and the system quickly switches to an energy-efficient mode.

Scenario 2: Cooling humid air

This scenario is the energy guzzler in the story. Because do you suffer from rising damp or a damp cellar? In that case, the air in the house is constantly saturated with water vapour. Humid air has an extremely high heat capacity and retains heat very effectively.

When you switch on the air conditioning, something frustrating happens. At first, the temperature in the house barely drops. The air conditioning unit first has to condense and remove thousands of litres of invisible water vapour from the air. This condensation process consumes a lot of energy. Only once the air conditioning unit has extracted kilos of water from the air can it finally start to actually lower the temperature in your home.

This situation is sometimes compared to a car’s handbrake. Running an air-conditioner in a damp home is like driving a car with the handbrake on. The engine therefore has to work extremely hard and consumes exponentially more fuel and electricity to reach the same speed – or, in this case, a comfortable temperature.

So, if the source of the moisture problem If this isn’t addressed, new moisture will constantly continue to evaporate from the air. Your air conditioning is trapped in an endless, gruelling cycle of latent cooling. This causes your air conditioning’s power consumption to rise.

Would you like a full explanation and in-depth insight into why high humidity turns your home into a sauna on hot summer days? Then be sure to read our blog about “Why your home feels like a tropical rainforest during a heatwave”.

The answer is ‘yes’. An air-conditioner It’s an excellent way to reduce the humidity in your home yourself. In fact, it’s one of the most effective ways to quickly get rid of that damp, clammy feeling in your home.

How can an air-conditioning unit reduce humidity?

Dehumidification of the home actually takes place automatically as a by-product of the cooling process.

Warm, humid indoor air is drawn by the fan past the ice-cold heat exchanger – the fins – of the indoor unit. Because these fins are ice-cold, the air around them cools down rapidly. Cold air can hold far less water vapour than warm air. As a result, the water vapour in the air condenses immediately on the cold fins, just like your breath on a cold car window. This liquid water is then drained outside via a condensation drain pipe. The air that the air-conditioning blows back into the room is not only cooler, but also much drier.

How do you set the air conditioning correctly here?

If you specifically want to reduce the humidity in your home using an air-conditioner, in which case most modern systems offer two options on the remote control.

1. The standard cooling mode: The unit actively cools the room to the set temperature whilst automatically dehumidifying the air at the same time.
2. The dehumidification mode: This is usually indicated by a drop symbol. In this setting, the fan runs at a lower speed and the compressor focuses solely on cooling the slats to draw as much moisture as possible out of the air, without making the room itself freezing cold.

The best setting for your wallet is to use the dehumidification mode wisely. Aim for a healthy relative humidity of 50% to 55% and don’t set the air conditioning to the very lowest setting unnecessarily. Don’t leave the unit running 24/7 either. Use timers to stabilise the humidity during the most humid times of the day. Also, ensure regular maintenance. Clean filters and a clear condensate drain ensure that the air conditioning dehumidifies much more efficiently, which helps you save on your air conditioning bills.

Now that we know that an air-conditioner can dehumidify, we come to the crux of the financial miscalculation involved in making your home moisture-free using an air-conditioning system. Many people therefore ask themselves: “How long does it take to dehumidify using air conditioning?” The honest answer is that, as long as the source of the damp lies within the structure of your home, the process of dehumidifying the air will never stop.

As soon as you switch off the air conditioning, the moisture from the damp walls or the cellar immediately evaporates back into the living space. Within a few minutes, humidity in the house is too high again, which means you have to switch the appliance back on. You’re literally trying to mop up whilst the tap’s still running.

The maths: How much does this stopgap measure really cost you?

Let’s put this to the test and work out the extra electricity consumption of your air conditioner when used as a dehumidifier. The formula for calculating your air conditioner’s consumption is simple. Convert the number of watts the air conditioner uses into kilowatts by dividing by 1,000. You then multiply this figure by the number of hours the air conditioner runs at this wattage. This will give you the total number of kWh your air conditioner uses to dehumidify the air in your home.

Let’s work through an example together. Suppose that, due to constant moisture infiltration, your air conditioning has to run for hours every day to keep the indoor climate comfortable:

• In that case, the additional power consumption for an average air-conditioner can easily reach 450 watts per hour. If the air-conditioner runs at this setting for around 6 hours, that amounts to an additional consumption of 2.7 kWh per day.
• On a monthly basis, we can therefore easily work this out by multiplying the figure for your additional consumption by 30 days. In this case, we arrive at 81 kWh per month of additional consumption by your air conditioning.
• So, over the course of a year, we’re already talking about hundreds of euros a year in extra electricity used purely to an existing damp problem to mask the problem rather than resolve it permanently.

So if that clammy, damp feeling comes rushing back the moment the air conditioning switches off, then your money is flowing straight out through a constant energy leak. You’ll never manage to reduce the humidity in your home permanently this way.

The secret behind that stuffy feeling at home has everything to do with the physics of our indoor climate. Many people therefore wonder whether the temperature affects the humidity in the home. The answer is, of course, a resounding ‘yes’, and it explains exactly why your home can feel so uncomfortable in summer.

At AquaConsult, during the hot summer months, we’re often asked: “When is the humidity in the house actually too high?” In winter, we tend to associate damp with condensation on the windows, but in summer the signs are more subtle.

So a humidity level of 70% indoors is certainly too high. But what does this actually mean for your comfort? And why does it feel so stifling?

The last straw

During a heatwave, something unusual happens to the humidity indoors.

• The sponge becomes saturated: The air outside is simply warmer, which means it is full of moisture due to summer evaporation. And during a heatwave, this air also seeps into the house, leading to higher humidity.
• The air cools down indoors, but the damp remains: As you’ve already taken all the necessary measures, it’s a few degrees cooler inside than outside. But when this warm, humid air cools down indoors, it shrinks, as it were. The sponge gets smaller, but the amount of moisture remains the same.
• The last straw: Because the cooler indoor air can hold less moisture as it contracts, the relative humidity shoots up immediately to 70% or 80%. The air is then supersaturated.

So why does this feel so ‘tropical’ and stifling?

This is the point at which your body starts to protest. Normally, the human body cools itself down by sweating. The normal, dry ambient air absorbs the tiny droplets of sweat, causing your skin to cool down.

But if the relative humidity in your home exceeds 70%, the air is already so saturated with water vapour that there is no room left for your sweat. The sweat can no longer evaporate and remains on your skin. Your body can no longer release its heat, making you feel stifled and as if there’s not a breath of wind to be found.

The signs: How can you tell if the humidity is too high during a heatwave?

As you don’t have the heating on in summer and the windows are often open, you don’t tend to see condensation on the windows. However, there are other, very clear signs that indicate the humidity in your home is too high.

• Damp sheets and furniture: You get into bed and the bedding feels clammy or almost damp, as if it hasn’t dried properly.
• A musty smell: When you walk into a room, especially the bedroom or the cellar, there’s a typical, musty ‘cellar smell’.
• Skin that sticks: Even if you’re sitting still with the fan on, your skin won’t dry out and you’ll still be left with a shiny, sticky film.
• Wood that swells: Kitchen cupboards, interior doors or wooden floors may suddenly start to stick or become harder to close because the wood absorbs excess moisture from the air.
• Unexplained patches of mould: Small, dark spots suddenly appear behind cupboards or in the corners of the bathroom and bedroom. This is because mould thrives in these warm, tropical conditions.

Do you notice any of these signs in your home? If so, there’s a good chance that the moisture balance in your home has been seriously disrupted.

When you start to break out in a sweat and the walls of your home begin to radiate heat, most Belgians’ first instinct is, quite naturally, to seek relief through natural ventilation. We open everything up.

Although this feels very intuitive, natural ventilation during a heatwave is, unfortunately, the biggest pitfall for your indoor climate.

1. Leave windows and doors wide open in the evening and at night

• The idea: It’s getting cooler outside, so if I open everything up now, the heat will blow out of the house.
• The pitfall: Yes, the outside air feels cooler on your skin in the evening and around midnight, but that same night-time air is often extremely saturated with moisture in the summer. By leaving your windows wide open for hours on end, you create a draught that literally lets litres of invisible water vapour into your bedrooms and living rooms. As soon as you close the windows again in the morning, the moisture becomes trapped. You are then literally bringing the heat into your home yourself.

2. Leave windows slightly ajar or in the ‘tilt’ position during the day

• The idea: If I let in a breath of fresh air, at least it’ll still be possible to breathe inside.
• The pitfall: Leaving a window tilted open during a heatwave is an open invitation to the hot, humid air from outside. The hot, humid outside air flows in slowly but continuously. Because it is slightly cooler inside thanks to your sun blinds, the incoming air cools down, contracts and causes the relative humidity in your home to rise immediately to between 70% and 80%. In doing so, you create exactly the greenhouse effect you are trying to avoid.

3. Relying on built-in window ventilation grilles

• The idea: My windows have ventilation grilles, so natural air circulation takes care of it.
• The pitfall: Window vents operate on the basis of wind pressure and temperature differences. On a windless, sweltering summer’s day, there is hardly any pressure difference between indoors and outdoors. As a result, the vents do absolutely nothing, or they passively allow the warm, humid air to flow in without any active extraction to counteract it. There is no control whatsoever.

4. Creating cross-ventilation

• The idea: If I open the front door and the back window at the same time, I effectively drive the warm air out.
• The pitfall: Although a breeze indoors feels wonderfully cooling on your sticky skin at that moment, you’re filling the structure of your home with damp air. As soon as the doors close again, the airflow stops and the oppressive humidity is trapped in your furniture, walls and fabrics.

With natural ventilation, you are completely at the mercy of the whims of nature. You cannot filter the airflow, you cannot regulate it and, most importantly, you cannot remove the moisture from the air. You are bringing the tropical climate from outside straight into your own home. Anyone who wants to keep their home truly comfortable and dry during a heatwave needs to move away from natural ventilation and opt for control with our solution.

Damp in the home is not a one-size-fits-all problem that can be solved with a single universal method. That is why we have identified seven specific moisture problems, each of which has a completely different cause and a unique technical guide for repair.

• Damp walls: This is a generally destructive symptom. The walls can become saturated from the inside or the outside, leading to crumbling plaster and an unhealthy indoor environment.
• Damp basement: As a cellar is located underground, this space is constantly under pressure from the surrounding groundwater. This manifests itself as water seeping in, puddles on the floor or extremely high humidity.
• Rising damp: Groundwater that is drawn upwards through the foundations and walls due to the absence or failure of an outdated flood defence, just as a sponge soaks up water.
• Penetrating moisture: Rainwater that penetrates through a porous façade or via cracks in the external wall during strong winds or storms, saturating the internal walls.
• Condensation moisture: The warm, moist air produced by cooking, showering, washing or breathing, which cannot escape and condenses on cold surfaces. This is often caused by a lack of proper ventilation.
• Mould on the walls: This is the direct, visible result of prolonged damp conditions in the home. Mould develops in stagnant, damp air and affects both the walls and your health to.
• Damp in new-build homes: This is often caused by construction moisture, residual moisture from concrete and plaster that has not yet dried out completely, or residual moisture left behind due to construction faults during a phase of construction carried out too quickly.

The crucial importance of an accurate diagnosis of fluid imbalance

Why is it so dangerous to diagnose yourself? Because the symptoms of these damp problems all look very similar, but the different moisture solutions differ greatly from one another. An accurate, scientific diagnosis of damp is therefore vital for a number of reasons, both for your home and your wallet.

• Avoiding inappropriate and extremely expensive treatments: This is the most immediate risk. If you think you are suffering from rising damp and have your walls treated with an injection process, whereas in reality the problem is penetrating moisture . In that case, you’ll have spent thousands of euros on a damp-proofing treatment that won’t stop the rain from getting onto the outside of your façade.
• Targeted use of specific solutions for fluid management: Every damp problem requires a unique, technical solution. Without the correct diagnosis, you’ll be in the dark as to what the right method is for resolving the damp problem.
• Excluding or treating hygroscopic salts: When walls remain damp for a long time, harmful salts build up in them. Even once the original cause has been resolved, these salts continue to attract moisture from the air. An expert can measure these salts, whereas a standard damp meter cannot. Without this knowledge, your wall will always feel damp to the touch.
• Identifying the root cause rather than simply treating the symptoms: Scraping away mould or painting over a wall with damp-proof paint is like putting a plaster on a wound. A proper diagnosis identifies the exact source of the damp, so that you can tackle the problem at its root rather than just temporarily covering up the damage.
• Financial peace of mind and a guarantee: Professional damp-proofing specialists such as us at AquaConsult We provide a long-term guarantee on the work carried out. This guarantee can only be issued and honoured if an irrefutable and accurate damp survey has been carried out beforehand. It protects you from recurring costs.
• Avoiding unnecessary demolition and cutting work: Sometimes a damp problem seems like a huge issue, but the solution is relatively simple. Without a professional damp survey you risk carrying out major demolition work which, in hindsight, turned out to be completely unnecessary.
• Legal and financial certainty in property transactions: Whether you buys a house Whether you are buying or selling, misjudging a damp problem can lead to unpleasant disputes over hidden defects. An official, properly documented diagnosis report provides certainty, in black and white, regarding the actual condition of the property.

In short: An incorrect diagnosis of damp can lead to incorrect, ineffective treatment and a waste of money. Only a watertight diagnosis guarantees a permanent and cost-effective moisture solution.

It’s tempting to hide a damp patch for a while with a strategically placed cupboard or to mask the musty smell with a scented candle. But don’t be fooled, because moisture problems are progressive. They never stop of their own accord and do not resolve themselves. In fact, the longer you wait, the greater the damage and the more complicated and expensive the repairs will be. If you ignore damp damage, you’re setting off a ticking time bomb that will take a heavy toll on every aspect of your life and your home.

1. The direct threat to your health and wellbeing

A damp home is an unhealthy home. When relative humidity If the humidity is consistently too high, you create the perfect microclimate for mould, fungi and dust mites.

• Respiratory problems and allergies: You and your family breathe in the invisible spores that mould releases into the air every day. This leads to chronic coughing fits, breathing difficulties, worsening asthma and persistent allergic reactions.
• Weakened immune system: Living in a damp environment triggers constant, mild inflammatory responses in the body. Babies, young children, the elderly and people with weakened immune systems are particularly at risk of serious health problems as a result.
• Rheumatic symptoms: A cold, damp environment also exacerbates the symptoms of osteoarthritis, arthritis and other rheumatic conditions.

2. Aesthetic and physical damage to your home’s interior

Damp spares nothing and no one. As soon as it penetrates your living spaces, the visual and physical deterioration of your carefully furnished home begins.

• Peeling wallpaper and flaking paint: These are often the first signs. Adhesive dissolves and paint cracks because the substrate is saturated with water.
• Rotten and warped timber: Wooden floors, skirting boards, interior doors and furniture absorb moisture, causing them to warp, expand or simply rot beyond repair.
• Damaged textiles: Curtains, clothes in wardrobes and fabric sofas kept in damp rooms will start to smell musty and may develop black mould stains that will never come out.

3. Structural deterioration of the building

This is where it gets really dangerous. Moisture doesn’t just remain on the surface; it penetrates deep into the core of the building materials.

• Crumbling plaster and brickwork: Quick-drying salts carried along by the moisture crystallise on the surface and literally push the plaster off the wall. The wall crumbles.
• House fungus (Serpula lacrymans): Every homeowner’s absolute nightmare. This aggressive wood-rotting fungus thrives in damp, dark spaces and, in no time at all, eats away at entire wooden joists and floor structures, posing a risk of collapse.
• Rusting reinforcing bars: In concrete structures, moisture penetrating the concrete can cause the internal reinforcing steel to rust. This steel expands, causing the concrete to crack and split.

4. A soaring energy bill

Did you know that damp walls your energy bill cause a dramatic rise in temperature? Water has an extremely high heat capacity.

• Loss of insulation performance: A damp wall loses all its insulating properties. The cold from outside seeps straight in.
• Burning more fuel for the same level of comfort: To heat a damp room, your boiler has to work much harder. You are literally heating water rather than air. This can lead to an increase in your energy bills of as much as 15% to 20%.

5. Drastic fall in value and legal risks associated with the sale

Moisture is the number one reason why prospective buyers to walk out immediately during a viewing.

• Financial loss: A property with visible or concealed damp damage will see its sale price plummet. Buyers will always use this as a reason to haggle tens of thousands of euros off the asking price.
• The Hidden Flaw: Are you trying to quickly conceal the damp damage with a new plasterboard panel or a fresh coat of paint just before the sale? If the buyer discovers the damp problem after the transfer of ownership, this may be legally classified as a hidden defect. The consequences include protracted legal proceedings, forced price reductions after the fact, or the complete cancellation of the sale.

In short: So waiting is not an option. By choosing today to an accurate, scientific diagnosis of damp, You protect your health, safeguard your capital and prevent a manageable damp problem from turning into a financial disaster.

When you set out to find the answers yourself, you’ll probably ask yourself: “How can I moisture problems ”How do you detect it?" The internet is full of quick fixes, and you can buy a simple damp meter online for just a few euros. You push the probes into the wall, the device beeps and the screen turns red. But what does that actually tell you?

Actually, very little. A moisture meter measures only the electrical resistance or conductivity at the very surface of the wall. As water conducts electricity, the device simply detects that this area is conductive and therefore concludes that moisture is present. It detects a symptom, but it does not carry out an analysis.

What a moisture meter doesn’t measure, and what is crucial

In order to reach an accurate diagnosis of damp and the correct moisture solution To get there, you need answers to questions that a moisture meter cannot answer.

• The exact extent of the problem: A moisture meter takes a superficial reading. It doesn’t tell you whether the wall is thoroughly wet or whether it’s just a wafer-thin layer of condensation on the outside of the plaster.
• The presence of hygroscopic salts: This is perhaps the device’s biggest blind spot. When groundwater or rainwater seeps into a wall, it carries salts with it. As the water evaporates, these salts are left behind in the wall. These salts are hygroscopic, which means they continuously draw moisture from the surrounding air. As a result, a moisture meter will trigger an alarm and indicate ‘wet’ due to the salts, even if the original source of moisture was sealed off months ago.
• The chemical composition of the water: Is the water in your wall caused by rain, rising groundwater, or is it hard tap water from a burst pipe? A moisture meter cannot tell the difference, yet this distinction is key to identifying the cause.
• The impact of humidity and temperature: Damp problems never occur in isolation; they interact with the indoor climate. A damp meter does not take into account relative humidity in space or the dew point, the temperature at which water vapour in the air turns into liquid water. Without this data, it is impossible to demonstrate the difference between condensation moisture and penetrating moisture.

Relying solely on a moisture meter is like a doctor taking your temperature, determining that you have a fever, and immediately deciding to operate without knowing where the infection is. In this case, measuring is far from knowing. To identify the actual source of the fluid, a more in-depth and scientific fluid analysis is required.

To the moisture problem To tackle the problem effectively, you naturally need to know what you’re dealing with first. Damp in the home never occurs without a cause and manifests itself in various ways. At AquaConsult, we identify seven specific damp problems, each of which poses its own risks to both your home and your health.

The short answer is, of course, “yes”. Moisture is harmful in every way. Before we look in more detail at what moisture does to your body, it is also important to understand the general consequences of an untreated damp problem in your home.

Property damage and a high energy bill are a pain, but you can sort them out with money. Your health and that of your family, on the other hand, are priceless. So you need to a permanent solution Choose a solution to your damp problem. Preferably today.

Biologically speaking, humans are not designed to live in a damp environment contaminated with mould spores. When the humidity in your home is consistently too high, you unknowingly inhale microscopic mould particles and dust mite droppings every second. Your body reacts to this with a series of physical warning signs.

So, what specific health issues can be linked to damp problems in your home?

• Chronic respiratory problems: Mould spores penetrate deep into your airways and alveoli. This leads to a persistent tickly cough, wheezing or rattling breath, shortness of breath and a blocked nose. It feels as though you’re stuck in a never-ending cold.
• Extreme fatigue and difficulty concentrating: In a humid room, your body finds it much harder to release heat through perspiration. This disrupts your natural temperature regulation whilst you sleep. You sleep restlessly, wake up more often and start the day feeling tired.
• Persistent headaches: Poor air quality and the constant presence of harmful substances in the air cause many people to suffer from chronic headaches that do not seem to go away with painkillers.
• Skin irritations and allergic reactions: Exposure to damp and mould damages your skin’s natural barrier. Existing skin conditions such as eczema or psoriasis can suddenly flare up again. You may also experience unexplained red patches, hives and intense itching.
• Irritated mucous membranes: The allergens in a damp home can irritate not only your lungs, but also your eyes and throat. This can result in burning, watery or red eyes, a dry throat and constant sneezing fits.
• Increased joint and muscle pain: Damp and cold air penetrate deep into your body. People with rheumatic conditions, osteoarthritis or fibromyalgia experience symptoms much more quickly in a damp home, as they become stiff more easily. Their daily pain and symptoms also become more intense.

What effect does a damp home actually have on your body?

A damp house is like a constant battle of attrition for your immune system. Because you are surrounded by harmful mould spores and allergens, your body’s natural defences are on high alert 24 hours a day. Your immune system becomes chronically overworked by the constant battle against these invisible invaders. This causes your resistance to drop drastically, making you more susceptible to infections and viruses. What’s more, damp air forces your lungs and heart to work harder to take in enough oxygen. Damp in the home therefore literally drains your body from the inside out, affects your energy levels and, in the long term, lays the groundwork for chronic, irreversible damage to your health.

At-risk groups: Why swift action is vital

Although a damp indoor environment is unhealthy for everyone, certain groups are particularly vulnerable. For them, an untreated damp problem not just annoying, but downright dangerous.

• Babies and children: Children’s lungs and immune systems are still developing. Children who grow up in a damp home with mould are up to three times more likely to develop chronic asthma, bronchitis and severe allergies later in life. A damp home therefore lays the foundations for a lifelong respiratory condition.
• Older people and those with chronic illnesses: Older people often have a naturally lower immune system. People who already suffer from lung conditions such as COPD experience breathing difficulties on a daily basis in a damp home. Furthermore, recovery from flu or a cold takes twice as long in a damp environment.
• Pets: We often forget, but our dogs and cats also suffer in a damp home. Because they spend more time on the floor and are therefore closer to rising damp or mould As they are exposed to these conditions, they inhale even more harmful substances than we do. This manifests itself in listlessness, bald patches in their coat caused by extreme itching, and chronic coughing fits.

Don’t wait until it’s too late: protecting your loved ones calls for action

Living in a damp home is a ticking time bomb for your health and that of your loved ones. This is therefore the moment when waiting it out is no longer an option, but becomes an unacceptable risk. Moisture problems These issues never resolve themselves; they only get worse by the day, and the impact on vulnerable groups grows. As a parent, partner or landlord, the key to a healthy future lies in your hands. Taking timely action is not a matter of aesthetics or property maintenance, but the ultimate act of protecting your tenants or family members. By taking action now and to tackle the root cause of the damp problem once and for all, you are choosing the health, safety and well-being of your whole family.

Before we dive into the numbers, we need to know what moisture enemy we are dealing with in your home. Moisture in the home comes in different forms. Recognising the specific moisture problem is therefore the first step towards the right solution.

Rising damp

Rising damp is one of the most persistent and structural moisture problems in older houses that do not yet have a good, watertight waterproofing layer. Groundwater then soaks up into the porous bricks.

You can recognise it by the moisture spots, salt efflorescence, loose plaster or flaking paint and wallpaper. And that mainly on the underside of the interior or exterior walls, approximately up to 1.20 metres in height.

Damp walls

When the walls feel constantly clammy, we speak of damp walls. This may be due to rising or penetrating moisture, but at least it causes the indoor environment to become unhealthy and the energy bill into the air. After all, dry walls insulate much better.

You will recognise it because the walls feel cold and clammy when you touch them. Stains or circles also appear on the paintwork and you notice that the humidity in the room remains high. In addition, you smell a typical musty odour as soon as you walk into the room.

Penetrating moisture

When your exterior walls are damaged, cracked or porous due to age, driving rain can penetrate deep into the facade. This is when we talk about penetrating moisture. The moisture then makes its way inside.

You recognise it by the moisture spots that are located at random heights on the interior walls. Often on the side where the wind and rain hit the façade the hardest.

A damp cellar

The basement is the lowest point of your home and is constantly under pressure from the surrounding groundwater. Especially during heavy rainfall, the hydrostatic pressure can become so great that water is forced through the basement walls or the bilge seam. Then you suffer from a damp cellar.

You will recognise it by puddles of water on the basement floor, permanently damp or shiny basement walls and a musty smell that permeates the rest of your home.

Condensation moisture

Condensation moisture unlike other moisture problems, is not due to water penetrating from outside, but purely to the lack of correct ventilation in the home. Daily activities such as cooking, showering, washing and breathing produce litres of moisture every day. If this warm, moist air has nowhere to go, it settles on cold surfaces and we speak of condensation moisture.

You will recognise it by the drops on the inside of the windows, musty smells and windows that remain tarnished for a long time after showering or cooking.

Mould on the walls

The direct and dangerous consequence of long-term condensation moisture or other untreated moisture problems is mould on the walls.

You will recognise it by the persistent, unsightly black mould spots and dots in the corners of ceilings, behind cupboards or in the bathroom and bedroom. This is not only detrimental to the value of your home, but also to your health.

Moisture in new-build homes

People often think that moisture only occurs in older houses, but nothing could be further from the truth. In the construction of modern homes, thousands of litres of water are used, just think of the concrete, screed and plaster. If a new-build home is sealed and insulated too quickly without building moisture can dry out completely, then the moisture remains in the structure.

You will recognise it by consistently high humidity in the new home, condensation on the windows and, in the worst case, immediate mould on the new plaster.

Many owners looking to sell their property ask us the question: “Can I selling my house with a moisture problem?” The short answer is: Yes, you are legally allowed to do so. However, you are obliged to explicitly disclose this to potential buyers, as moisture damage falls under the duty to report defects. Do you fail to do so? Then you risk legal proceedings afterwards for hidden defects.

So the conclusion is very simple: do nothing about the moisture problem is not an option. Hiding the moisture problem is not allowed and leaving the problem untreated will cost you more at sale than the actual treatment price of the problem. By intervening now, you will remove buyers' doubts and protect your own wallet.

Meanwhile, we have the moisture problem recognised and understand its risk to your loss of value. Now it's time for the solution. Once you detect the moisture problem, you can take proactive action to stop the loss of value of your home and turn it into an added value.

At AquaConsult, we don't believe in treating symptoms. We tackle the source of the moisture problem. Depending on the exact diagnosis made by our experts, we put one of our targeted and professional solutions In.

1. Injecting walls

• Deployed at: Rising damp and persistent damp walls.
• The solution: Injecting walls. Our experts accurately drill holes in the affected walls just above the floor. They then inject a high-quality, environmentally friendly gel. This gel spreads into the pores of the masonry and forms an impenetrable, water-repellent barrier. From then on, the groundwater can definitively no longer climb up.

2. Remediation of plastering

• Deployed at: Walls damaged by rising damp or damp walls.
• The solution: The remediation of plastering. Only inject the walls is often not enough. Over the years, walls have absorbed salts from groundwater. These salts continue to draw moisture from the air, even if the wall has been injected. Our experts remove the old, affected plaster down to the stone and then apply a special salt-resistant membrane. Afterwards, they also provide professional re-plastering. This will make your walls perfectly even, dry and paint-ready again.

3. Basement sealing or caulking

• Deployed at: A damp cellar and basement infiltration.
• The solution: With a professional basement sealing or waterproofing our experts make the basement walls completely waterproof again. They first fix the walls mechanically and then apply various waterproof cementing layers, mortars and coatings. The vulnerable bilge seam is also made impermeable in the process. Your basement transforms from a musty storage area to a perfectly dry and usable room.

4. Basement drainage

• Deployed at: A damp cellar with extremely high groundwater pressure.
• The solution: Basement drainage. Sometimes the pressure of groundwater is so great that a traditional basement is not sufficient. In that case, we at AquaConsult opt for basement drainage. Our experts dress the basement with a special bubble membrane that collects the water seeping in in a controlled way and leads it via built-in channels to a collection pit. An automatic submersible drain then drains the water to the sewerage system. Your basement is guaranteed to stay dry and usable.

5. Concrete injection

• Deployed at: Moisture in new-build homes and basements with cracks in concrete.
• The solution: In modern homes or cast concrete basements, settlement or shrinkage can cause a crack in the concrete where water seeps through. With concrete injection we solve this locally and effectively. Under high pressure, we inject a special polyurethane resin directly into the crack. This resin reacts immediately as soon as it comes into contact with water. It foams up, expands and completely and permanently seals the crack to its deepest core.

6. Facade impregnation

• Deployed at: Penetrating moisture and porous exterior walls.
• The solution: Facade impregnation. Our experts first thoroughly clean the external wall and then apply a transparent, breathable coating to it. This impregnating agent soaks deep into the facing bricks and joints. As a result, the driving rain beads off the wall and can no longer penetrate. And that while the façade can still breathe from the inside.

7. Mechanical ventilation

• Deployed at: Condensation moisture and mould on the walls.
• The solution: The only way to banish condensation and mould for good is controlled air circulation. AquaConsult installs smart and energy-efficient ventilation systems. These systems continuously measure the humidity in the house. As soon as it gets too high, while showering or cooking, the humid air is automatically removed and replaced by healthy, dry outside air. No more condensation and therefore no more mould on the walls.

Moisture problems often sneak into your home unnoticed, but the damage to your home and your wallet is enormous. To tackle the problem, you first need to know which variant it is. Each type of damp has its own specific cause and characteristics. They also each need to be solved structurally in their own way.

1. Damp walls

‘Damp walls’ is a general term for interior or exterior walls that are saturated with water and therefore moisture due to an external or internal problem.

• How do you recognise it? The walls feel clammy or even cold. You can often recognise them by peeling paint, peeling wallpaper, circles on the plaster or a musty smell in the room.

2. Damp basement

Because a basement is underground, the walls and floor are constantly under great pressure from the surrounding groundwater. Therefore, moisture may find its way into the basement.

• How do you recognise it? You recognise a damp cellar to puddles of water on the floor, crumbling cement occupancy, salt efflorescence on the walls and stored items becoming mouldy or smelling musty. Moisture also often migrates into the living spaces above.

3. Rising damp

Rising damp occurs when groundwater slowly soaks up walls like a sponge due to the absence, wear or failure of a water barrier.

• How do you recognise it? You see it mostly on the ground floor, low to the ground up to 1.20 metres high. Think loose skirting boards, damaged plaster and a white, powdery salt rash on the bricks.

4. Penetrating moisture

Penetrating moisture occurs when rainwater penetrates from outside to inside through a porous façade, cracks in the external wall or damaged pointing.

• How do you recognise it? This type of moisture is not connected to the ground and can therefore occur on any floor. You can recognise it by moisture spots that appear in random places on your interior walls. Especially often after it has rained heavily.

5. Condensation moisture

Condensation moisture is the precipitation of warm, moist air from e.g. cooking, showering or breathing that lands on cold surfaces. This happens when this air, due to a lack of ventilation cannot escape.

• How do you recognise it? It is the biggest culprit in bedrooms, kitchens and bathrooms. You can recognise it by continuously fogged-up windows and puddles of water on window sills.

6. Mould on the walls

Mould on the walls is the direct and especially unhealthy result of a long-term and untreated moisture problem, where the combination of moisture, heat and stagnant air is the perfect breeding ground.

• How do you recognise it? You can recognise it by the typical unhealthy black, green or grey spots in the corners of the room, behind cupboards or on the ceiling.

7. Moisture in new-build homes

Moisture in new-build homes, also called construction moisture, are the thousands of litres of water used during the construction process that have not yet had a chance to fully evaporate or dry out.

• How do you recognise it? Through windows that constantly store heavy vapour, a clammy feeling in a brand new house and plaster that just won't turn completely white.

Why exactly are energy bills skyrocketing at moisture problems in the home? The link between moisture and energy consumption is physical. Moisture not only changes the properties of the air, but it also affects the materials and installations in your home.

1. Heating or cooling water costs a lot of money

When dealing with condensation moisture or building moisture then there is a large amount of ‘invisible’ water in the air. We know from physics that water has a much higher heat capacity than dry air. Noticeably more energy is needed to air-condition water particles than to get dry air to the right temperature.

• In autumn and winter: Your central heating system or heat pump has to work harder to get the humid air warm. You are heating up litres of water in the air and that requires a lot of energy.
• In spring and summer: When you try to cool with air conditioning, the system has to dehumidify the heavy and clammy air before the temperature can come down. This causes your air conditioner to run at full power for an unnecessarily long time.

2. Your insulation material loses its effectiveness

Insulation materials work best when the house is dry, because it holds still and dry air. Dry air conducts heat poorly, keeping the indoor temperature stable. Once rising damp, penetrating moisture or a damp cellar saturates the walls, the moisture also soaks into the insulation.

Since water conducts heat and cold just right, your insulation layer turns into a cold bridge. In cold periods, heat flies out and on hot summer days, heat comes in faster. You immediately lose the return on your precious investment in insulation, which means your heating or air conditioning has to run constantly to compensate for the loss.

3. Continuous heat loss through ventilation

When we suffer from a clammy air, musty smell or mould on the walls is the automatic reaction to open windows and doors wide to ventilate. Although ventilation is crucial, this manual ventilation without a smart ventilation system for a huge energy loss. With this, you constantly let the warmed or cooled indoor air escape. Afterwards, your boiler or heat pump has to start all over again to air condition the air coming in.

4. Loss of efficiency and wear and tear on your installations

Because a humid home constantly requires extra energy, your boiler, heat pump or air conditioner has to run on high power much more often and for longer. This has major drawbacks for your wallet.

• Higher consumption: Installations operate outside their most efficient comfort zone, causing unnecessarily high gas or electricity consumption.
• Faster wear: Constant overloading causes the components of your plant to wear out faster. This leads to premature maintenance costs or a shorter life of your expensive equipment.

5. Using electric energy guzzlers as emergency solutions

A lot of households struggle with damp walls or a damp cellar and then reach for temporary aids out of helplessness. Just think of installing electric supplementary heating in chilly rooms or running loose, electric dehumidifiers continuously. Such devices take a lot of power. They solve the cause of the moisture problem neither, but do cause your electricity bill to skyrocket.

6. Damage to the thermal capacity of the structure

Not only the air, but also the structure of your home absorbs moisture for problems such as rising and penetrating moisture. A dry, solid wall has the ability to store heat and slowly release it back into the room. A wet structure loses this function completely. The walls no longer store heat, but instead conduct the cold or heat from outside directly inside.

Damp walls and a damp cellar not only affect the figures on your energy meter, but also disrupt your daily living comfort. When walls contain moisture, they remain cold to the touch. This causes the so-called cold-wall effect.

The Energy Performance Certificate (EPC) indicates how energy-efficient a home is. The score is expressed in a label ranging from A+ (very energy efficient) to F (an absolute energy guzzler). This label is based on the calculated energy consumption per square metre of floor area (kWh/m² per year).

When is an EPC label really bad and what does it mean for your wallet? In Flanders, EPC labels E and F are seen as the most negative scores. Since the introduction of the renovation obligation a label E or F means that your home is officially categorised as an energy sieve. That is, the house uses more than 400 kWh per square metre for label E or even more than 500 kWh for label F of energy per year. In practice, this translates to high energy bills, a chilly indoor climate and a home that literally loses heat.

Many people think that a lack of insulation is the only reason for a poor EPC label. But, of course, this is not true. Untreated moisture problems are often the invisible driving force behind these poor scores. Now, moisture has a negative impact on your EPC label on three crucial levels:

1. Thermal conductivity: damp walls do not insulate

The EPC software calculates the insulation value of your walls based on stagnant air. Air insulates, but water conducts. Water conducts heat up to 25 times faster than air. If you are dealing with damp walls, then the bricks and cavity fill up like a sponge.

Whether it is rising damp that pulls up from the ground or penetrating moisture where driving rain penetrates a porous façade, the result remains the same. The cold from outside is drawn in via the moisture at lightning speed, while the heat from your central heating system flies out via the same route. A wet or damp wall loses up to 80% of its original insulation value.

2. The impact on indoor air: Heating humid air is costly

The EPC label looks at the efficiency with which a home can be heated. If there is heating by a damp cellar continuously evaporates water in the living spaces, relative humidity rises to 70% or 80%.

Physically, water has a much greater heat capacity than dry air. This means that your boiler has to consume much more energy to heat humid air one degree than dry air. As long as the humidity does not decrease by addressing the source of the moisture, your energy consumption and thus your EPC score will remain artificially high.

3. Moisture creates building knots and stubborn mould

Building nodes or thermal bridges play a huge role in the calculation of a modern EPC label. These are simply the places where insulation is interrupted and therefore heat leaks out. This is the ideal breeding ground for condensation moisture, because warm and humid indoor air settles on the cold walls, resulting in mould on the walls. Mould not only affects health, but it is the visual evidence of a structure that is severely underperforming energetically.

Moreover, moisture penetrating deep into the structure can structurally attack materials, causing micro-cracks and destroying the airtightness of the house. Even in new projects, we see this danger. Moisture in new-build homes, namely building moisture, which is not drained in time and correctly, can drastically reduce the insulation values of thick layers of insulation within the first year. The result is an unexpectedly poor EPC label for a brand new house.

The impact of a poor EPC score now directly affects your home on several levels. Therefore, ignoring a bad EPC label has long since ceased to be an option.

In short, addressing your EPC score is not an unnecessary luxury, but a necessary investment that pays for itself immediately. By strategically raising your energy label, you protect yourself from fines, increase the market value of your property and put the brakes on high monthly energy costs. It is the only way to turn your house back into a financially sound, future-proof and comfortable home. But to achieve that label leap, you have to start at the root of the problem and thus permanently fix the moisture problem.

Not every moisture problem is immediately visible behind a fresh coat of paint. Whether you have your eye on a charming renovation house in the city or a more recent new construction in the countryside, a sharp eye is always crucial.

Saving tip: Notice any of these things? Then be sure to take pictures of them if you plan to buy your dream home anyway. These are your key pieces of evidence to knock hundreds of euros off the asking price during the price negotiation. After all, a house with damp is worth less, while with the right expertise is often solved faster than you think.

To draw up a budget for your dream home, you do need to know which moisture enemy you are dealing with.

Moisture control is tailor-made. To give you an idea of the budget to provide during your negotiations, we have our specialised moisture solutions including guide prices listed.

Injecting walls against rising damp

When no water barrier is present, groundwater migrates up the walls. The most effective solution is to professionally injecting the walls with a water-repellent gel.

• Target price: From €100 per running metre.

Basement sealing or basement waterproofing

Is the basement of the property you have your eye on damp? At basement waterproofing or caulking, we make the walls and floor completely waterproof with several layers of cementation. This turns the basement back into a usable storage or living space.

• Target price: From €50 per sq m.

Basement drainage

When the groundwater pressure under the house is too high for an ordinary basement pit, basement drainage the only definitive solution. This involves the controlled discharge of water via a pumping system.

• Target price: For a total basement project, expect a starting price from around €2,000.

Concrete injections for leaks

In modern houses or basements made of concrete, hairline cracks or bilge seam problems can cause acute water infiltration. Concrete injection seal these leaks under high pressure.

• Target price: This price strongly depends on the severity of the leak and is customised during our free expertise.

Facade impregnation or hydrofuge

Does the property suffer from penetrating moisture? By the facade impregnation, we apply an invisible, protective layer that repels rainwater while the wall continues to breathe.

• Target price: This can be done from as little as €8 per m².

Ventilation system against condensation and mould

Moisture in the house does not always come from outside. Condensation and mould on the walls often indicate a lack of air ventilation. A professional ventilation system removes polluted, moist air and brings in healthy air.

• Target price: Ventilation solutions start from €1,000.

Plastering and finishing

After moisture control themselves, the walls often need to be repaired. AquaConsult also provides the plastering so your walls will be completely even and paint-ready again after treatment.

• Target price: The price of this depends on the surface area and the condition of the substrate.

How much budget should you provide in total now?

While the exact cost will depend on the severity of the damage and the total area, it is essential to plan a realistic overall budget before purchase to meet moisture control to be able to do so. For an average family home where the ground-floor walls need to be treated against rising damp, combined with a professional finishing of the plastering, you should consider a total budget between €3,500 and €7,000.

If there is also a damp cellar which needs to be fully waterproofed, the total renovation budget rises to between €8,000 and €15,000. By mapping out this total amount, including margin for contingencies, in advance, you will be in a stronger position during negotiations and avoid putting pressure on your renovation budget after purchase.

This typical musty smell, which we often describe as ‘wet dog’ or ‘an old cellar’, does not happen by accident.

So when we talk about this odour, we are actually talking about a complex biological and chemical process that takes place invisibly in the walls and air of your home. To understand how to permanently remove the odour, you need to know what the source of the problem is. This is why science breaks down this characteristic into three crucial factors.

1. Microbial Volatile Organic Compounds (mVOCs)

The smell we describe as musty is referred to in science as mVOCs. These are actually gaseous by-products released during the formation of fungi and bacteria.

From the moment a material such as plaster, wood or insulation becomes damp, it becomes a breeding ground for fungi and bacteria. Microorganisms then literally start eating or digesting the materials. During this digestion process, they emit gases. So what you smell in your home is not the moisture itself, but the chemical emissions from the active moulds that are deep in the pores of your home. Even if you can't see the mould yet, you can already smell it.

2. The role of relative humidity (RH)

The air in your home works like a sponge. Warm air retains more water vapour than cold air. When the relative humidity rises above 60%, the air in the house becomes saturated.

In this saturated state, two things happen:

• Odour retention: Moist air particles or water molecules bind to odour molecules from, for example, cooking, pets or smoke. As a result, these odours linger longer and feel heavier.
• Surface absorption: Excess water vapour in the air finds a way out and condenses on cold surfaces such as the walls or windows. This keeps the process of mould and associated gas emissions (mVOCs) continuously.

3. The ‘chimney effect’ and diffusion

Why do you often smell the musty smell throughout the house, even if the problem is located in the basement? This is because of the laws of thermodynamics. Warm air simply rises. As this air migrates to the upper floors, it creates negative pressure in the lower parts of the house.

This causes moist and mould spore-laden air from the basement to be sucked upwards through cracks, holes in pipes and stairwells. We also call this the chimney effect. This directly affects the air quality in your living room or bedroom by a moisture problem which is located metres below.

A musty smell in your home is rarely the result of a single problem. It is often a combination of environmental factors and the construction of your home.

If the musty smell lingers in the house, chances are it is due to a structural moisture problem that negatively affects air quality day and night. At AquaConsult, we often see our clients smelling the odour but unable to place the source. Therefore, we list the possible culprits.

Rising damp: The constant evaporation

Rising damp occurs when groundwater soaks into the walls through the foundation. This often happens in older houses that have no or damaged flood defences.

• How do you recognise it? Due to wallpaper coming loose, peeling paint or plaster powdering at the bottom of the wall. Sometimes you can also see white salt efflorescence on the wall.
• Impact on air quality: The wall behaves like a large radiator that constantly evaporates clammy moisture into the room. This creates structurally excessive humidity (often above 70%), making the air feel heavy and stuffy.
• The musty smell: The smell is often earthy and clammy, similar to the smell of wet earth or a forest walk after a rain.

Moist basement: The smell factory under your feet

The basement is below ground level and under constant pressure from groundwater. In the absence of a watertight basement forces moisture out and creates a damp cellar.

• How do you recognise it? Puddles of water on the basement floor, clammy walls, a musty smell as soon as the basement door opens or mould on cardboard boxes and wooden shelves.
• Impact on air quality: Through the ‘chimney effect’, cold, humid basement air rises into the rest of the house. As a result, the air quality in your living room or bedroom is directly affected by the polluted air from downstairs.
• The musty smell: The classic, pungent cellar smell. A pungent, mouldy smell that clings to textiles and clothing.

Penetrating moisture or damp walls: The porous barrier

Rainwater penetrates deep into interior walls through a porous façade, cracks in masonry or damaged pointing. When this is the case, we speak of penetrating moisture or damp walls.

• How do you recognise it? Due to moisture spots on the interior wall that get bigger after a heavy rain or an exterior wall that stays dark and wet for an extremely long time after precipitation.
• Impact on air quality: Wet walls lose their insulation value, lowering the indoor temperature and increasing humidity. This creates a cold and unpleasant indoor climate.
• The musty smell: A smell of wet masonry and lime. It is an odour that often comes and goes, depending on weather conditions.

Condensation moisture: The saturated atmosphere

Condensation moisture occurs when warm, moist air cools on cold surfaces due to a lack of ventilation.

• How do you recognise it? The water droplets on the windows, black mould dots in the corners of the ceiling or mirrors that stay fogged up for a long time.
• Impact on air quality: The air becomes saturated and consumed. As the air is not refreshed, mould spores and bacteria accumulate. You literally breathe polluted air.
• The musty smell: The smell is often musty and slightly sour, typical of active fungal growth on organic material such as wallpaper or paint.

Mould on the walls: The active air pollutant

Mold is the direct result of long-term moisture problems. It is a living organism that feeds on your home.

• How do you recognise it? To black, green or white spots and fluffy textures on the walls, ceilings or behind furniture.
• Impact on air quality: Mould continuously emits spores into the air. This drastically lowers air quality and is the biggest culprit for occupants' health.
• The musty smell: A very strong and suffocating odour. It smells like spoiled material and is often the most disturbing smell in the house.

Moisture in new-build homes: The trapped building moisture

Thousands of litres of water are used during the construction process. If this is not allowed to dry out sufficiently before you move in, it will remain the building moisture caught in the construction.

• How do you recognise it? Due to constant clammy air, windows that fog up even with light heating and the house never really feeling warm despite insulation.
• Impact on air quality: It prevents the natural drying of the house and causes excessive humidity from day one, which prevents the growth of the first fungi can encourage.
• The musty smell: A subtle but noticeable smell of damp concrete and stucco that becomes unfresh over time.

Before you open the toolbox, you need to know what causes the moisture problem is. Moisture control is bespoke. Solving one moisture problem is counterproductive for another.

From the moment many people discover a moisture problem, the first question they ask themselves is, “How do I get moisture out of my house as soon as possible?” For different moisture problems, there are different ways to do this. At condensation moisture or building moisture helps intensive ventilation. But beware, because when it comes to a structural problem such as rising damp, then merely opening a window will never solve the root of the moisture problem.

Not every humidity problem requires immediate major intervention. What you can do yourself to bring down humidity in your home:

When moisture problems beyond a fogged-up window, the following mistakes are often made in terms of DIY moisture control.

1. Repaint with anti-humidity paint

This is the biggest and most common mistake when it comes to fighting moisture. Getting rid of a damp wall or mouldy spot with special paint seems quick, but you are locking the moisture in, so to speak. The water seeks another path, often higher up the wall, while the internal structure of your home slowly rots away. You are not addressing the moisture problem, you are covering it up to the naked eye, while it slowly breeds further within the structure of your home.

2. Impregnating the facade incorrectly

The self injecting an external wall or the façade at penetrating moisture is risky. If the façade is not 100% free of cracks, you are again trapping moisture, but behind the protective layer you are applying to the façade. At the first night frost, the water expands and your bricks and joints may simply crack.

3. Installing a false wall against a damp wall

When you don't see it, the moisture problem is already solved for many. This is especially thought to be the case with a damp cellar or room. By installing a plaster wall in front of the moisture problem, you no longer see it, but this way you create a perfect breeding ground behind the wall for unhealthy moulds which you breathe in unnoticed. In the long run, you may experience health problems if you do not solve the moisture problem permanently.

4. Self-injecting walls against rising damp

We often get asked if you rising damp can fight yourself. Indeed, there are do-it-yourself kits you can use to fight your can inject walls, but these are often not powerful enough for thick walls. Without professional equipment, chances are that the barrier will not be fully opaque, so moisture will simply continue to rise in the wall.

5. Failure to distinguish between building moisture and leaks

In new-build houses, moisture spots are often thought to be just construction moisture. As a result, many new owners ignore a real leak or a construction fault, with all the consequences for your new plastering.