Tips for avoiding uneven cooling with AC

“Why is the upstairs not as cool as the downstairs and what can we do to even it out?“ This has become a popular question as Seattle is having more 80 degree days, and adding air conditioning is getting more common. We custom install AC systems throughout the Puget Sound and have tips to maximize your overall cooling comfort.

Your house was built for heating

Northwest houses, even ones built recently, are built with ductwork that supports efficient heating, not cooling. (Many older homes weren’t built with enough ducts even for the heating.) The majority of Northwest homes don’t have sufficient airflow in upper floors of the house for effective cooling. Our ducts aren’t large enough and they are in the wrong spots. It takes a lot of cool air to overcome the heat gain on higher floors. Case in point, your registers are most likely in the floor, because hot air rises through the room. But cold air sinks! So that cold air is fighting gravity to get to you. In southern US homes, where cooling is the major season, their registers are in the ceiling.

Say no to vent closing

Many people want to try to even out cooling between floors by shutting the registers downstairs in hope that more cool air goes upstairs. This is not a good idea and does not work. Your system was sized to fit your house based on having those registers open to provide air flow to and from the equipment. Shutting one or two in a whole house is okay, but more than that and you put undue static pressure on the equipment. Said another way, this could damage your coil and greatly shorten the life of your AC equipment. Think of it like driving your car with the parking brake on!

Tips to improve upstairs cooling

If you have a big remodel of your upstairs in mind, that would be the time to permanently solve this issue by adding or enlarging duct work through the walls and ceiling. Another option, especially good for larger homes, is to have two separate heating and cooling systems – one for each floor. These are expensive solutions, and if this type of remodel is not in the plan, we have more practical tips:

1. Start your AC early in the day

Heat rises so by the time you get
home the natural forces will make your upstairs hotter than the downstairs. Cranking the AC will start the process of cooling it down, but the upstairs will take longer because it had a chance to get hotter. Newer air conditioning systems are energy efficient, so the extra electricity used from running it on low during the day vs cranking it up when you get home, will be minimal. And you are giving it a better chance of overcoming the heat gain throughout the house.

2. Insulate your attic and upstairs walls

Insulation will keep the cool air in, and proper sealing and caulking of bathroom fans, windows and balcony doors will keep heat outside. Insulation is a great year round energy saving investment and there are excellent utility rebates to help you do this affordably.

3. Add a solar attic fan

Adding a solar attic fan can affordably drop your upstairs a few degrees by pulling cool air upstairs and sending the hot air out of the roof. It will help to even out the temperature in a cost effective way.

4. Add a return air vent to improve system air flow.

This is less expensive than new ductwork and may make a small improvement.

5. Get good blinds

Keep heat out. Get good blinds, particularly on the south and west sides of the house, and keep them shut during the day. Keep windows closed until evening. Remember that heat will rise, so leaving windows and blinds open downstairs will disproportionately heat the upstairs.

6. Consider a ductless heat pump

For an old Craftsman house where the upstairs has little to no ducting and is too cold in the winter, and too hot in the summer, consider a ductless heat pump for the upstairs, as it will independently heat and cool that area without the need for ductwork.

Whatever you choose, Washington Energy Services is Puget Sound’s leading contractor providing tailored home comfort solutions including: energy efficient air conditioning, heat pumps, ductless split systems, insulation and solar attic fans. Are you planning to add air conditioning to your home? Contact us for a free estimate and stay cool this summer.