Feeling the chill? HVAC pros reveal if you should close your window’s trickle vents in winter

With January in full swing, the colder weather has well and truly set in, with frost, sleet and snow a regular sight.

More often than not, this drop in temperature will also be reflected inside your home, regardless of the heating and draft-proofing measures you may have taken.

So, should you close your window's trickle vents in winter to keep things more cozy? Here, HVAC experts explain how to keep your house warm without turning up the heat, and share why it's actually best to keep your trickle vents open.

Should you close your window's trickle vents in winter?

In short, no.

Whilst in winter, one of the most important things when keeping a home warm all day is using DIY draft-proofing tips to keep the heat in, it may surprise you to know that, in general, HVAC experts don't recommend closing your window's trickle vents.

These are the small air flow vents integrated into window frames and doors, which are often used as a way to ventilate your home in winter without increasing energy bills.

Kevin Goude, experienced HVAC expert and owner at First Choice, says, 'It depends on your home's insulation, HVAC system, and local climate, but generally no, you don't need to close them. These vents help maintain airflow, reduce your home's humidity, and prevent mold growth, even in winter. Closing them may lead to stale air and condensation inside windows, which can affect both your home and health.'

Josh Mitchell, HVAC technician at AirConditionerLab, also points that that without fresh air, pollutants and allergens are unable to escape, 'which might make air quality issues worse for everyone, particularly those with respiratory conditions.' This means closing your window's trickle vents is a mistake compromising your home's air quality that is best avoided.

While Mitchell and Goude both appreciate that a minimal loss of warm air and a slight increase in outdoor noise are potential drawbacks, they can easily be overcome. 'The warm loss can be mitigated with energy-efficient solutions like space heaters (such as the Dreo Space Heater for Inside available at Walmart) and there are modern vents that have a high degree of soundproofing, such as the SF Xtra Sound Attenuator (Acoustic) Vent available at Titon,' recommends Goude.

To get the maximum benefit from your window's trickle vents, Goude recommends using them differently in different rooms.

'In high-moisture areas, like the basement, kitchen and bathrooms, keep them fully open. For all other rooms, such as living rooms, dining rooms and bedrooms, use the partially open mode.

'And, upgrade vents by using activated, cut-to-fit carbon filters in them, such as the Breathe Naturally Universal Cut To Fit Activated Carbon Air Filter available at Amazon – they can be trimmed to fit various vent sizes, including trickle vents.'

If you have a considerable amount of condensation in your home, opening windows in winter will reduce condensation, and balance airflow in your home, even throughout the colder months.

If you're unsure how often you should open windows in winter, this will vary depending on the weather, but, in general, no longer than a few minutes is more than enough to improve ventilation in your home and avoid any habits that increase the risk of mold.

'Though it might feel like you're letting in cold air, the airflow from open trickle vents is minimal but essential,' says HVAC technician Mitchell. 'It helps keep your home's air clean and healthy, which is always a plus during the colder months. If you're worried about losing heat, focus on other ways to keep your home warm, like using draft stoppers (such as the HomeProtect Door Draft Stopper available at Amazon) or improving insulation, without sacrificing good air circulation.'

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