How To Prevent Condensation On Windows – The Ultimate Guide

It’s early in the morning, you’ve just woken up, and you see a bit of moisture either on the outside or inside of your windows. Is this a cause for concern?

Condensation on windows can be a sign of poor ventilation, broken seals, or air leaks. It can potentially lead to mold or mildew within your home if not taken care of.

There are many different ways to reduce and prevent condensation on windows before having to even consider replacing your windows. In this article, we’ll be going over all of the different ways that you can use. They are in no particular order. Try one and see if it works before going to the next. Or you can try them all.

Ultimate Guide to Reduce and Prevent Condensation on Windows

It is common to see condensation on your windows when temperatures start to drop. A little bit of condensation here and there is natural. But when left to pool and seep into your home, it can lead to unwanted serious damage.

Let’s go over many of the different ways we can prevent and reduce condensation on your windows.

Check Windows for Broken Seals or Air Leaks

Condensation or a foggy look inside of your windows is a common sign that your window’s seals are broken.

Get Your Windows Seals Fixed Using Its Warranty

Before trying to fix anything yourself, check if you have a warranty!

If your window is new and has been replaced in your home in the last couple of months or years, you can contact the people who installed them. It is highly likely that something went wrong on their side, whether it be damage while shipping your windows, poor manufacturing, or an installation fault.

Your window installation most likely came with a warranty up to 15 years. It depends on the company and contractor you went with, of course. If it was a big company, they are very good about their warranty.

If your windows are older than 10-15 years or is outside of your warranty window (Get it?), your seals might have broken due to the changing seasons. Fluctuations in temperature cause glass to expand and contract. Over time, this puts pressure on your seals, causing them to break. This is more likely to happen to your windows that get a ton of sunlight.

How To Tell If Window Seals Are Broken

Here’s how you tell if your window seal is broken and if air is leaking through them. These are things to check for if you have double-pane or triple-pane windows.

  • Your windows have a foggy look to them or have condensation in between your window panes.
  • You’ve cleaned your windows on the outside and inside, but they still appear dirty with dust and dirt between your window panes.
  • Run your fingers along your window frame. If you feel any air drafts coming in, then there is a broken seal.
  • There are small insects between your window panes.

Double-pane and triple-pane windows have a airtight space between the pieces of glass. This space is filled with gas to improve the insulation properties of your windows. When this space is no longer airtight, your windows are not functioning as they properly should.

Single-pane windows are just one piece of glass. You can still check for air drafts coming through, but condensation on them is completely normal. There are ways to decrease this, but it won’t have anything to do with the window performance itself. We’ll get into those methods soon.

Check Ventilation

Ventilation is the process of air moving around your home. Without ventilation, the air in your home is stale and old. Ventilation replaces old air with new air and keeps the house “breathing.”

Other methods we’ll discuss will go under “improving ventilation.” Here are a few things to look for that are quick fixes.

  • When showering, use your bathroom exhaust fan.
  • When cooking, use your kitchen exhaust fan.
  • Make sure your dryer vents are properly sealed.
  • Clean out your exhaust fans.
  • Leave space between furniture and walls to allow air to circulate.
  • Open your drapes or blinds.
  • Open windows whenever possible. Even a crack will help.
  • Use ceiling fans or other fans to move air from one place to another.
  • Replace your air filters regularly, and install them properly.

Not only will these things decrease condensation on your windows, it’ll also improve the air quality inside of your home. You’ll be breathing in more fresh air rather than stagnant air.

Use Ceiling Fans

graphic of ceiling fan direction clockwise in the winter vs counter clockwise in the summer

Ceiling fans are particularly useful in the winter time to reduce condensation on your windows. They are not a 100% foolproof solution, but they are an easy one to implement.

Using your ceiling fans improves the airflow of the rooms in your home. In the wintertime, your fans should be spinning slowly clockwise to move the warm air that accumulates on your ceiling down.

On your fan, there is a switch above the blades that will reverse its spin.

It may seem weird to turn on your ceiling fans in the winter time, but it actually helps distribute the warm hair inside of your home.

Warm air naturally rises, so having your fans run clockwise will pull up the cool arm and push down the warm air.

This also helps keep your home warmer, so you can save money on energy bills in the cold weather.

When your fan is on, stand under it, look up, and make sure that it’s going clockwise instead of counter-clockwise. Keep it on the lowest spin setting, so that you get the benefits from the fan without feeling the breezy chill.

Open Your Windows

This is another quick solution to reduce condensations on your windows, and it can work almost immediately.

It’s also strange for someone to say “open your windows” in the middle of winter.

After a warm shower or cooking in the kitchen, opening up the windows helps reduce the humidity in the room.

In the mornings after you wake up or whenever you see condensation forming, open up your windows just a crack for about 30 minutes to an hour.

This will reduce all of the condensation that’s been forming in that room or the areas close to that window, such as the walls, behind furniture, and possibly even inside cupboards and drawers.

Use Exhaust Fans In Kitchen and Bathrooms

The kitchen and bathroom are areas inside of your home that tend to have high humidity because there is a lot of warm air from heating up water, either for cooking or from showering and bathing.

Turn on these exhaust fans while cooking or showering. The most important thing to remember is to just turn them on and then keep them on. It’s not for long.

After doing any of these activities, make sure you run the exhaust fans for 20-30 minutes after you’re done to ensure that you reduce the moisture content of the air.

Another helpful tip is to close the door to your bathroom whenever you do shower or bathe. That way, the moisture stays in the bathroom and then gets exhausted by your fans instead of making its way around the home to other areas with no exhaust fans.

These fans also help reduce condensation and fog on your mirrors and shower walls as well as the windows.

Turn Down Humidifier

To you, it may be comfortable to run the heater and the humidifier, but that also forms the perfect growth conditions for mold as well.

The relative humidity inside of your home should be between 30% and 60%, at the very highest.

If you start seeing condensation on your windows, it’s best to turn down or turn off the humidifier for a couple hours to let the condensation dissipate.

On especially cold days where temperatures drop drastically, consider lowering your humidifier along with it. Having high relative humidity inside of your home encourages condensation to form on your windows.

Consider a Dehumidifier

If you’ve done a lot of the methods listed here, it might be time to think about getting a dehumidifier. It’s exactly what it sounds like, it takes out humidity from the air.

By doing so, a dehumidifier reduces the relative humidity levels in your home. This creates conditions where condensation doesn’t occur and mold doesn’t grow.

A dehumidifier can be used in any room as well. You can use it in your bathrooms after showers to remove moisture in the air or in the kitchen while cooking. If you air dry your laundry, which isn’t recommended if your humidity levels are already high, a dehumidifier can help with that too.

The most important thing to consider here is the size of your dehumidifier relative to the space that you are trying to treat. You might even have to get several ones to space out around the house. There are even different types of dehumidifiers.

Dehumidifiers can range in price from $25 all the way to a couple thousand of dollars for a whole-house one.

Which Dehumidifier to Get: Desiccant or Refrigerant

There are two types of dehumidifiers, and they both work differently to remove moisture from the air in your home. These two types are a desiccant dehumidifier and a refrigerant dehumidifier, which is also called a compressor dehumidifier.

What is a Desiccant Dehumidifier?

A desiccant dehumidifier uses an absorbent material AKA a desiccant to remove water from the air. This material absorbs the moisture, the machine dries the material, and then the moisture is exhausted outside of your home.

A desiccant dehumidifier works similar to when you use a sponge to clean your wet countertop. Imagine you have a wet countertop, this is similar to moisture in your air. You take a sponge and soak up the water. This is what the dehumidifier takes when it absorbs moisture. Then you take your sponge and wring it out over the sink, akin to the dehumidifier exhausting the water outside of your home.

These dehumidifiers tend to be used for industrial spaces because they can stand up to extremely harsh environments. These dehumidifiers are best for ships, basements, factories, and other environments that get extremely high humidity levels.

Desiccant dehumidifiers are great for the following reasons:

  • No compressor or refrigerant
  • Can work in extremely low temperatures
  • No drainage required
  • No need to install ducts prior to turning it on
  • Plug in and turn on
  • Quiet

However, they also have their downsides too:

  • Raises the temperature inside the space by 10-15 degrees
  • More expensive
  • Take a lot of energy to run
What is a Refrigerant Dehumidifier?

A refrigerant dehumidifier is also called a compressor dehumidifier. This is because it uses a refrigerant or cooling material in combination with a compressor to remove moisture from the air.

It works very differently than a desiccant dehumidifier. A refrigerant dehumidifier takes in humid air and then uses a cooling coil to lower the temperature of the air to the dew point. Water condensates around the coil and then removed through a drainage duct. The remaining air is warmed and then put back into your home.

You can choose the relative humidity level that you want, and it works similar to how you can set your AC/heat temperature to a certain temperature. The dehumidifier won’t run when the relative humidity level is at the desired number.

Refrigerant dehumidifiers are great for the following reasons:

  • Affordable to buy
  • Can get different sized dehumidifiers for different parts of home
  • Lower energy costs to run
  • Can set a desired relative humidity level

However, they also have their downsides too:

  • Requires more maintenance and upkeep and empty regularly
  • Louder due to its compressor
Desiccant VS Refrigerant Dehumidifiers

For a house, a refrigerant dehumidifier is a better and more reasonable option.

It uses much less energy and can regulate the relative humidity level and temperature of your home much better than a desiccant dehumidifier can. They are also more affordable options and have sizes that are appropriate for a single room inside of your home.

Once you get a dehumidifier that suits your needs, make sure that it’s regularly maintained for optimal usage.

Open Your Drapes

Another easy quick fix that can help reduce condensation is to open up your drapes, especially overnight as droplets form as temperatures drop. This helps the air around your windows circulate around your home rather than being stuck near the window.

If the air stays suck there, it’ll get colder and reach its dew point, resulting in higher amounts of condensation.

Condensation around your drapes can also lead to moisture getting trapped and contribute to mold and mildew growth as well.

If opening up your drapes at night is difficult to do because of intrusive street lights or car lights driving by, investing in lighter and thinner drapery will still help with air circulation around your windows.

Keep Your Heat On Constantly

If you’ve done everything so far and you still have condensation forming around your windows, chances are that the internal temperature of your home is too low or the temperatures of your home swings too wildly from cold to warm.

This can happen when you keep temperatures low at night when you sleep but turn it up when awake. The sudden swing in temperature encourages condensation to form.

Keeping the temperature more stable throughout the day can help reduce condensation. A higher temperature prevents the air from hitting its dew point and turning into condensation.

Warmer air can hold more moisture than cold air. If the moisture is in the air, then it can’t be on a glass surface.

This may be a very expensive option for you to do. In this case, you can choose to keep the heat running on low all day or use a burst of energy to make sure the air hits a certain temperature before letting it drop down before running it again.

This way, your furniture and drapes will hold some more warmth and help regulate the air’s temperature.

Make sure that your home has insulated windows and walls before resorting to this option, or else you will lose much of the heat that you’re spending your money on anyways.

Getting Low E, argon-filled, double-pane windows can definitely help with keeping the temperature of your home more level around your desired temperature. It also helps to check the seals around your windows to make sure you aren’t losing precious warm air to the outside.

Add Weather Stripping

Weather stripping is used to seal air leaks around windows. Typically, this is done with caulk.

Weather stripping is only useful if you have checked your windows for air leaks and drafts. If there are none, then your windows are already sealed properly.

Other than caulk, there are types of weather stripping such as:

  • Felt
  • Foam
  • Vinyl
  • Metal
  • Tension seal, also known as V strip
  • Tape
  • Magnetic
  • Fin seal

After you choose your materials, the next step is to measure how much weather stripping you need.

It’s better to have too much than to not have enough, so add about 10% to your measurements.

Most weather stripping materials come with instructions on the package, so follow those closely if you’ve never used it before.

Some common advice prior to weather stripping includes:

  • Have more weather stripping material than you have measured to account for any waste or improper cuts.
  • Apply weather stripping on clean and dry surfaces.
  • Measure twice, cut once.
  • Apply with pressure evenly and make sure the fit is snug from both sides.
  • For windows, apply the weather stripping between the sash and the frame, but make sure your windows still operate properly.

After you’re done applying the weather stripping, check again to make sure it’s a snug fit and that the material compresses when the window is closed.

Also check for any air drafts or improper seals. And that’s all, good job on applying weather stripping. Hopefully, this helps reduce condensation around your windows.

Move Your Indoor Plants Outside

There are different types of plants. Some plants are natural dehumidifiers, where other plants will increase the humidity level of your home.

Releasing moisture into the air is a natural part of a plants “breathing.” They take in water through their roots and release over 90% of that back into the air once they’re done with it.

Having dehumidifying plants is a great thing to try out because it’s a natural solution with no harsh chemicals. Plants also don’t require any electricity to run.

Here is a good list of indoor houseplants that absorb moisture in areas like the bathroom.

This list includes English ivy, peace lilies, orchids, palms, ferns, and more.

If you love your humidifying plants, you can move them outdoors to reduce the moisture they release into your home. It’s also possible to keep them in a place where the relative humidity is lower in your home, so that they don’t make the problem areas worse.

Use a Window Insulation Kit

A window insulation kit is a budget-friendly way to improve the insulation of your windows. It costs about $5 and maybe an hour or two of your time.

It consists of tape and a plastic film that shrinks when exposed to heat. To use these kits, you will need a hair dryer or a heat gun and a pair of scissors.

Here is an example of a window insulation kit that you can find in your local hardware store such as Home Depot or Lowe’s. The kit that’s linked here can insulate about 3 average-sized windows. If your home has 30 windows, it would cost approximately $50 for enough kits to cover them.

These kits are not an end-all-be-all solution because you still want to make sure that your relative humidity levels indoors remain low enough where condensation doesn’t form and mold doesn’t grow. This involves turning up the heat, making sure your windows are properly sealed, having proper insulation and circulation, and all of those things we’ve covered so far.

However, you may be in a situation where those things may not be entirely feasible such as when renting an apartment or a home. A window insulation kit could help you out.

These kits act similar to how a double-pane window acts, although not as good. It adds an extra layer of insulation, albeit a thin one, that can help to prevent heat loss through your windows.

There are mixed reviews on whether these window insulation kits actually work to prevent heat loss and condensation through your windows. Some people swear by it. Others think it’s a waste of money. Because it’s a very affordable solution, it may be worth trying anyways.

Keep Inside Doors Open

Another quick and easy fix is to keep your inside doors open. Similar to turning on the fan, this allows stale air to circulate around your home instead of sitting in one room.

One room in your house may be more humid than the next one. By keeping doors open, you can change out the air more frequently.

The only time when it’s recommend to keep inside doors closed is when you are cooking or showering and running the exhaust fans. This keeps the moisture inside those areas while your exhaust fans are taking that moisture-filled air outside of your time.

When combined with ceiling fans, this is an effective way to circulate warm air throughout your home.

Replace Your Windows

Last, but not least, you can consider window replacements. This is especially helpful if you have single-pane windows where it’s extremely likely to see condensation occur since these windows do not offer much insulation by themselves.

There’s no layer of gas in between to slow down heat exchange or film to reflect heat.

Replacing single-pane windows to double-pane windows makes a gigantic difference when it comes to reducing condensation and improving the insulation abilities of your windows.

If you have double-pane windows area, it would make sense to replace them if you have tried all of the other methods. Perhaps your windows are very old and the air seals are broken beyond repair or your windows are not inoperable or damaged by mold or mildew.

Now it makes sense to consider the pricey investment of a full house window replacement.

Contact your local contractors or window company to get the best prices for your project. It also helps to ask them plenty of questions to ensure that you know all of your options for your window replacement project.

Where Is The Condensation Coming From?

Indoor vs Outdoor Condensation

Outdoor condensation is when moisture appears on the exterior side of your windows – the side facing the outdoors. This is completely normal condensation. It forms when the window is colder than the dew point.

Air naturally has moisture, or water, inside it. The dew point is the temperature when this water vapor goes from being a gas to a liquid, and then you can see it on glass surfaces.

When you have a cold glass soda bottle, warm air surrounding the bottle hits the glass. This decreases its temperature, which makes the water in the air turn into a liquid that appears on the surface of the glass. The same thing occurs to your windows. Your window is the glass. The outside air hits your window and turns in a liquid.

Indoor condensation is condensation that happens in between your window panes. This is when it’s a problem. The moisture is stuck between two pieces of glass. You can’t wipe it from the outside or from the inside.

The humidity level inside of your house is too high. Ideally, your home should be around 30% humidity in the winter time. Most thermostats come with a humidity meter, and you can check it on there.

If the indoor temperature of your home is between 77°F and 86°F with relative humidity above 55%, mold will grow rapidly. The relative humidity level inside of your home should not be higher than 60%.

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