While fall might be just around the corner, temperatures don't show any sign of dropping anytime soon. In fact, in some parts of the US, they're still climbing. But with energy costs also continuing to climb*, how can you beat the heat without spending a penny?
Well, say our HVAC experts, there's one unusual hack that homeowners are relying on to keep cool and comfortable – opening their attic to allow heat to rise.
Here, they explain this clever way to keep a home cool this summer.
How does opening your attic work to reduce temperatures at home?
According to Josh Mitchell, HVAC technician at AirConditionerLab, 'Opening your loft hatch to help cool the house is a simple trick that actually works better than people expect, especially in homes without central AC.
'When you open the loft hatch, think of it like opening a damper. You’re creating a low-resistance path for heat to rise out of your living space. It works even better if your attic already has some form of passive ventilation like ridge, soffit, or gable vents.'
Alex Atkinson, plumbing and HVAC expert at Super Brothers, also agrees that this is a clever and effective way to keep your home cool. In fact, he says, 'Leaving your loft hatch ajar to allow air to circulate through and bring cooler air in can be surprisingly effective in keeping a home at a comfortable temperature, especially during summer.
'The principle behind this trick lies in the fact that cold air sinks and hot air rises,' he explains. 'Leaving the loft hatch open creates a means of escape for hot air that is trapped against the ceiling while allowing cooler air from lower levels to circulate more readily.
'Essentially, it helps your property get to an even temperature without having to resort to air conditioning immediately,' or in cases where you don't have AC to use.
How to use this hack effectively in your own home
If you'd like to try this unusual method to keep a home cool in a heatwave, it really couldn't be simpler. The best way to do it, advises Josh, is to speed up the process by making use of your best fans, as 'you want to move the air, not just rely on natural flow.'
'A fan pointed upward at the loft hatch pushes warm air through the hatch and into the attic space, accelerating the stack effect,' he shares. 'At the same time, set up box fans or window fans on the lowest floor to pull in cooler air from outside.
'This creates a full airflow path: Cool air in, hot air out. This setup can drop upstairs bedroom temps by four to seven degrees Fahrenheit within two hours, depending on how well the home is insulated and how cool it is outside.'
If you only have one fan, he adds, put it at the base of the stairs pointing upward – Josh assures that even a small 12-inch fan, like this Comfort Zone Table Fan available at Amazon, can help to significantly improve circulation.
In any case, you'll get even better results if you crack a window.
'It will perform even better if you also employ cross-ventilation by having windows on the shaded side of your home open to bring in cooler air and vent out the warm air through the loft,' says Alex.
'It is like a natural ventilation system, removing stagnant warm pockets of air that make your home feel suffocated.'
As with anything, though, stresses Josh, safety is key – if your loft hatch opens down with a pull-down ladder, make sure it's locked in place, he directs, as a loose hatch can shake or even fall with a strong breeze from a fan.
'One more thing,' he adds. 'Check to make sure your attic is actually vented. If you open the loft hatch and your attic has no ridge or soffit vents, you’re only pushing hot air into an even hotter space.
'If the attic feels like an oven with no airflow, you may need to add passive vents or install a solar attic fan [such as the iLIVING HYBRID Ready Smart Thermostat Solar Roof Attic Exhaust Fan available at Amazon]. Those usually cost around $100 to $300 and can help long-term.
'If your attic has insulation blocking the soffit vents – which I see all the time – even passive airflow gets choked off. Pull that insulation back or use baffles so that hot air can actually move upward and out.'
What to shop
All prices were correct at the time of publication.
'For attic airflow, I like using this Lasko box fan,' says Josh. 'It’s cheap, durable, and moves a lot of air fast.'
'If you want something quieter for overnight use, this one from Vornado is a solid pick,' recommends Josh. 'It moves air across a room and won’t sound like a jet engine.'
'You can also add a smart plug like this to control the fans based on time or temperature using your phone,' suggests Josh. 'That way, you can set it to run only at night when the outdoor temperatures are cooler.'
'For longer-term attic venting, solar-powered attic fans like the this are worth a look,' says Josh. 'They install on the roof and start moving air out as soon as the sun hits them.'
'I usually suggest high-quality energy-efficient fans like this, which is very effective at boosting airflow without being excessively noisy,' says Alex.
This attic ladder pull-down system kit is super quick to install, and makes it easy to open and close your attic door as and when you need to.
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'If you don’t have central air and rely on portable or window AC units, this method reduces the workload on those units and can improve efficiency,' concludes Josh. 'Less trapped heat means shorter runtimes.'
It's also crucial to ventilate an attic, particularly if you want to avoid mold growth and musty odors.
*According to the U.S. Energy Information Administration.
