Condensation on the windows

Condensation is not exclusively a winter-time effect. As the warmer weather arrives, we start using air conditioning to cool our homes inside, and condensation can form on the exterior sides of windows. In summer, the weather outside heats up. Inside your home, the air conditioning cools the air to make it colder than the outdoor temperature. This sets up the conditions for condensation when warm, humid outside air meets the colder glass surface of your windows.

In cold months, you may have noticed that condensation is more noticeable in the early mornings or after sunset or late at night. This happens because dawn and dusk hours and late-night are usually the cooler periods of the day, so condensation on windows is more likely to occur during those hours.

In hot months, condensation is most likely during the peak heat hours of the day, from early- to mid-afternoon. In the part of the day that requires the most home heating in winter and the most home cooling in summer, condensation is more likely to happen.

In other words, condensation is more likely during whichever hours there is the greatest contrast between indoor and outdoor air temperatures. Then, depending on temperature and humidity variations, the condensation may dry up as temperatures rise through the day.

Seeing condensation on your windows might seem like a problem. You may worry that your windows are defective or not energy efficient enough. But, the reality is actually the opposite. The condensation indicates that windows are doing their job well in providing a barrier against the transfer of heat or cold from outside air into your home.

You are using air conditioning or heating to create interior conditions that are significantly warmer or cooler than the outside environment. Condensation on windows confirms that you have succeeded in controlling your indoor environment. The condensation indicates that high-quality window construction and good workmanship in the installation are likely contributing to the optimum performance of your energy-efficient windows.

It further means that the window seals and weatherstripping are airtight and that your window glass type is performing well in protecting your home against external heat and cold.

Additionally, it can mean that the vapor barrier material and insulation around your windows are also doing their part to aid indoor climate control. Certain degrees of difference between inside and outside air temperatures and humidity can lead to condensation on energy-efficient windows. Condensation happens if the windows are sufficiently energy-efficient to prevent:. For maximum energy-efficient performance, have your energy-efficient windows installed by factory-trained and industry-certified professionals.

Low-E glass coating helps block heat or cold from transferring from the outside to the inside of your home. By minimizing the transfer, low-E glass enables the exterior surface of window glass to cool along with the outside air, while the indoor side of the glass remains warmer.

When indoor and outdoor temperatures and humidity levels combine in certain ratios, condensation can develop on the Low-E window coating. Alternatively, less energy-efficient windows are less likely to have condensation.

Condensation in hot or cold months is a good indicator that your new energy-efficient replacement windows are performing well to help make your home comfortable in summer and winter. It may be necessary to investigate other possible causes and determine how to prevent window condensation if it is due to special issues in or around the window installation. You can reach our friendly, knowledgeable customer service team by calling or reach us online.

Because, as explained, condensation is a natural response to the successful blocking of hot and cold air transfer between the interior and exterior of your home, occasional condensation is to be expected. Most homeowners will simply elect to wait briefly for the temperature contrasts to reduce naturally during the day. Some people may choose to wipe condensation off windows. Remember that it can reappear as long as the temperature and humidity conditions for its redevelopment are present.

As mentioned, if you are concerned that the cause of condensation is not the temporary contrast between indoor and outdoor conditions, ask for help. Examine conditions in and around the room for potential issues with plumbing, HVAC outlets, leaks, etc. If no external issues appear to exist, contact your Advanced Window Products expert to assess possible issues with the window installation. We are Utah's leading window manufacturing company. We build the best energy-efficient vinyl windows and glass doors for Utah homes.

Download PDF. If the room was originally constructed with a fireplace, but this has since been blocked up, check that adequate ventilation has been installed, which usually means wall vents or air bricks. Pay close attention to the ventilation in rooms where steam is produced, ensuring that bathrooms are fitted with extractor fans where possible.

After a shower or bath close the bathroom door and open the window to allow the moist air to escape outside, not into the rest of your home. Try to dry clothes outside when possible to avoid hanging them in the house and causing more moisture to form in the air.

You might find a dehumidifier of particular use in a conservatory or orangery over winter. Single glazed windows will inevitably cause condensation over the colder months as the glass cannot warm up. Replacing single glazing with double or triple glazing will give the window an internal layer of glass, insulated from the temperatures outside, which can warm up with your room and reduce condensation. This will also help to keep the room warmer, enabling the air to hold onto more moisture.

Slightly increasing the temperature in your home will help the air retain water rather than allowing it to condensate. You still need to ventilate the rooms well, which will allow the water vapour to escape. Installing radiators under your windows can also be useful as it will help to keep the inner pane of glass warm and prevent water vapour condensating on it. The same applies to heated towel rails in bathrooms.

Water vapour has nowhere to go and the glass is being kept cold, so condensation will inevitably occur. Consider keeping the heating on in that room, perhaps installing thermostatic radiator valves so you can control the temperature separately to the rest of the house.

You should also ensure that the room is well ventilated, perhaps by keeping the windows open a little or installing a dehumidifier. There is little you can do to prevent external condensation. You should find that external condensation only lasts for a few hours in the morning before the warmth of the sun or air movement from the wind dries it.

This has a hydrophilic coating that repels water, minimising the effects of condensation. In standard double or triple glazing this should not occur as the unit should be hermetically sealed to prevent any water vapour getting in. So, if you do have condensation between your window panes, this is a sign that the seal has failed and the unit should be replaced.

If you have secondary glazing installed alongside single glazed windows, the unit will not be hermetically sealed, and therefore some condensation in the cavity may occur. Pop into our showroom for a chat or call us on 45 71 45 to speak to one of our experts.

What is condensation? Edit this Article. We use cookies to make wikiHow great. By using our site, you agree to our cookie policy. Cookie Settings. Learn why people trust wikiHow. Download Article Explore this Article parts. Related Articles. Article Summary. Part 1. Install a hygrometer. A hygrometer is a device that measures moisture levels in the air.

Since condensation forms when warm moisture in the air collects on a cold surface, such as a window, tracking the humidity level in your house can help you stop condensation. When the moisture levels in the house get too high, take steps to reduce the humidity. When the temperature outside is below 0 F C , keep the humidity in your house between 15 and 25 percent. When the temperature outside is between 0 and 40 F and 4 C , keep the humidity inside between 25 and 40 percent.

Use exhaust fans and vents throughout the house. One of the best ways to get humidity out of your house is to vent it outside through exhaust fans. Using exhaust fans is important in certain rooms and with certain appliances that produce moisture. Run them for at least 20 minutes after your shower. Use kitchen and stove fans when you're cooking. Run them for about 15 minutes after you finish cooking.

Make sure your dryer vents to the outside for when you're doing laundry. A gas fireplace must have a chimney that vents outside, and you should always keep the damper open when you're having a fire in a wood burning fireplace. Take your plants outside. Indoor plants can be great in your home, but if you have trouble with condensation, you should keep them outside whenever possible.

This is because plants produce moisture, so keeping them inside can exacerbate condensation issues. If you have a sun room that stays dry, you can also keep your plants there. Line dry clothes outside. If you must line dry your clothes, take them outside to prevent water from evaporating off the clothes and adding excess moisture to the air inside.

If you must line dry clothes inside, keep them in a well-ventilated room, and open a door or window. Close doors when bathing and cooking. When you shower or bathe, close the door to the bathroom to keep steam and moisture from escaping into the rest of the house. When cooking, close doors to the kitchen to keep moisture contained. When you are cooking or bathing in a closed off room, open windows to help remove the moisture.

Use lids when cooking. Another great way to contain moisture when you're cooking is to use lids that will keep liquids inside the pans and pots. This is especially important when you're steaming and boiling food. When you do remove the lid from your dishes, do so in front of an open window, and make sure the exhaust vent is running.

Turn off any humidifiers. Humidifiers are designed to add more moisture to the air in your house, so they will cause more condensation to form on your windows. When you're experiencing moisture problems, turn off all the humidifiers in your house, including ones that are attached to the furnace. Use a dehumidifier. On the other hand, dehumidifiers are designed to remove moisture from the air, so these are ideal devices if your home is prone to condensation.

You can either install a whole-home dehumidifier, or invest in a portable one that you can move around the house.

Part 2. Keep your house at the right temperature. Managing the temperature inside your house is an important part of controlling condensation. Condensation can only form if there's a cold surface where the moisture can pool, so keeping windows and walls warm is essential. During the cooler months, use your furnace to increase the temperature, especially if humidity levels start to get too high. If the humidity levels start to exceed 50 percent, take steps to lower the humidity and increase the temperature until the humidity drops below 50 percent.

Install weather stripping.