Why is There Condensation on My Drive-Thru Windows?

If you’ve been in the restaurant business for some time, you may have noticed your drive thru service windows fog up occasionally.

Due to the insulating properties of energy efficient glass, condensation can collect on the window in certain conditions. Not every type of window will experience condensation, and certain times of the year cause more condensation than others.

Exterior Condensation

Exterior condensation on your restaurant drive-thru window is created by the same conditions that create dew or frost on grass and vehicles overnight. The condensation is created because moist air comes into contact with cooler surfaces, like glass, and the dew point of the air is higher than the temperature of the surface. This occurs primarily during Spring and Fall, when nights are cooler than the days.

You may notice condensation not appearing on your less energy efficient drive-thru windows, and that is because of the heat from the interior escapes through the window. This keeps the exterior temperature of the glass warm enough to prevent condensation from forming.

Condensation appears on energy efficient drive-through windows because the window is functioning properly. The window does not allow as much warm interior air to escape, so the exterior of the window stays cool, causing condensation but lowering your heat loss and utility costs.

Interior Condensation

Interior condensation on your drive thru service windows is caused by high humidity and low air exchange inside the facility. In older buildings, gaps were often in the windows which allowed for the exchange of air between the interior and exterior and was usually adequate at preventing the buildup of condensation.

Modern day service windows are designed to keep the air inside of buildings, reducing heat loss. This, however, also reduces air flow. The most efficient way to prevent interior condensation is to use an air curtain, which keeps ambient or heated air flowing in front of the inside of the window. If an air curtain isn’t a solution you’d like to explore, you could increase the interior’s ventilation by opening the windows for a few minutes each day – especially during steam-producing activities like grilling or frying.

Apart from the above, there are some other factors that can influence condensation, which include:

Window Size: Larger drive thru or patio windows may be more likely to show condensation;

Window Location: Small differences in placement can result in condensation on some windows but not others, even if they’re side by side. Windows more exposed to the wind are less likely to show condensation;

Air Circulation: The more air flow to the outside and inside of your window, the less likely it is to show condensation;

Weather Changes: When there is a drastic shift between outdoor and indoor temperatures over a short period, condensation is more likely to form;

Moisture Between Panes: Moisture build up between panes of glass could be due to a failed insulating unit, and should be repaired.

At Easi-Serv, a drive thru windows manufacturer, we offer a variety of drive thru service windows that can suit your every need. All of our windows are durable, have a 5-year best-in-industry warranty, and are guaranteed weatherproof. We not only manufacture ready-made windows but can build the perfect custom window to address your needs.

If you have any questions about our services or products we would be happy to assist you. You can reach out online or by phone at 1-888-591-0106.