My parents still live in the house I grew up in, a small two story house in rural Illinois.
My parents share a bedroom on the main floor, where the kitchen and living room also reside. The upstairs mostly just contains two bedrooms and a small “landing” connecting the two.
Since it’s just the two of them living there now, there’s little use for them to go upstairs most of the time. So, in order to save money, they’ve just installed a thick curtain leading to the upstairs and closed all of the air vents up there. They open up the vents a day or so before guests come so those rooms can reach a reasonable temperature.
In the summer, it gets stifling hot up there without the vents open. It’s pretty chilly up there during the winter without the vents, but not freezing (thanks to the rising heat from below).
The thing is, the climate upstairs really doesn’t matter to my parents. They almost never go up there, so why should they bother spending a dime heating or cooling that area?
Closing that area off simply saves them money. They’re not wasting energy cooling the hot upstairs during the summer or heating the cold upstairs during the winter, and that savings is reflected on their energy bill.
At our house, we only have one room worth closing off – the guest bedroom. Most of the time, we keep the door shut and the vent in that room closed. We only open it up a day or two before guests come so that the room will be pleasant for them.
How much does that save us? It’s really hard to accurately judge it, but I can say that during the summer, we don’t save very much because the guest bedroom is usually cool except on the hottest of days. During the winter, however, it can get downright cold in there, which means we’re saving money on heating.
Closing off a room is pretty simple. If you have forced air heating and cooling, just close the vent in that room and keep the door closed. You can also stuff a towel or something like that underneath the door to stop the air flow even more.
If you’re closing off an entire floor, as my parents are doing, you might want to check out the ventilation coming out of your blower unit, which you’ll usually find near your furnace. Often, there will be a separate vent for each floor in your home, so simply shutting off that single vent will do the trick. In these cases, there’s often a small wing-tipped bold that you can turn to close off the air flow to the desired floor. This isn’t true for all forced air systems, but it’s true for many of them, particularly newer ones.
If you have baseboard heating, see if there are specific controls for the room you wish to cool and turn them all off.
How much will you save? It depends on a lot of factors, ranging from the insulation in your home to how well the room is sealed off. The simplest way to see that you’re saving money is to compare the temperatures inside and outside of the sealed room. The greater the difference, the more you’re saving.
If you have a room that you’re not using, take the simple steps of closing the vents in there and keeping the door closed. Those steps will save you on your energy bill.