Owners of two-story homes know the dilemma well: The upstairs tends to be hotter and the downstairs cooler. This makes managing the thermostat challenging. Why does your home have these temperature differences, and what can you do to make things more comfortable throughout the house?
Baby, it’s cold downstairs
The problem is one of thermodynamics. Heat transference makes colder air sink to lower spaces while warmer air rises to higher ones. In winter, your HVAC has a hard time keeping the downstairs comfortably warm because the heat rises to the second floor. In the summer, the cooler air downstairs feels nice, but the upstairs is warmer than you want.
Here are steps you can take to help moderate home temperature differences.
Start with temperature differences in the attic
To make the upstairs more comfortable, start at the very top. Make sure you have plenty of insulation in the rafters between the attic spaces and the upstairs rooms. If you don’t already have a radiant barrier on the underside of the roof decking overhead, consider having one added.
Examine recessed lighting fixtures and return air vents in the attic to ensure there’s a good seal around them. Make sure you have adequate weather stripping around the edges of attic doors and ceiling hatches. Put a layer of insulation on hatch doors.
Windows and their coverings
The upstairs windows can be another source of heat transference that contributes to temperature differences. Keep shades drawn to insulate from the hot rays of the sun. If your windows themselves are older and not energy efficient, shop for new ones, particularly those with “low-E” glass, which inhibits heat transference.
When you are upstairs, use ceiling fans. They don’t actually cool the air but they keep it moving, which makes you more comfortable.
Addressing the temperature difference in the HVAC system
Have your HVAC system inspected and serviced once a year. Head off problems in advance that could contribute to inefficient operation. Have the HVAC pro inspect the ducts for any leaks, especially the ones that service the upstairs. Perhaps it’s warmer there in summer in part because the cool air is leaking out before it even arrives in upstairs rooms. Inadequately sized ducts and return registers upstairs can also contribute to temperature differences, so have an HVAC pro check to see that they’re the proper size.
Keep your heating and air-conditioning filters changed on a regular basis. Allowing air filters to become clogged with dust makes your HVAC system work harder, contributing to uncomfortable air temperatures and higher energy bills.
If you have one HVAC system and one thermostat to service both stories of your house, talk to your HVAC professional about investing in a zoned system. This would provide each floor with its own heating and air as well as thermostat. Although a significant investment, zoned systems make it much easier to achieve balanced air temperatures than does a single system servicing both floors.
Related – Saving Green With a Home Energy Audit