A common wisdom in the energy savings world is to turn down the temperature on your thermostat at night to save money. While it is sound advice, there are several factors you should consider before determining what temperature will save you the most money and conserve the most energy, while making your home comfortable.
Gas furnaces, as well as electric, oil, and propane furnaces are able to heat the house up to daytime temperatures quite quickly after being turned down at night. On these furnaces that have a well sealed and insulated duct system, we recommend turning the thermostat down 5-6 degrees when you go to bed. Heat pumps, on the other hand, take much longer to recover to normal daytime temperatures, so we only recommend setting the thermostat back 3-4 degrees. If you set it back much farther than that, the heat pump will kick into auxiliary mode in the morning, which to explain it quickly is essentially a “booster mode” used to help the temperature in your home rise faster, but it only ends up costing you more money over time.
However, there is a wild card that affects how swiftly your furnace or heat pump can recover in the mornings when you wake up. Most people don’t think about it, but the duct system that carries the air from your furnace to the individual rooms of your home has to be in good condition to rapidly heat the home back up. If the duct work is not properly sealed and insulated, then we recommend not setting the thermostat back as many degrees at night, simply because it will take much longer to recover in the morning. If you think about it, a lot of heat is lost from duct work that has holes or minimal insulation, so the heat that should be getting to your house is instead heating your crawl space or attic.
During extremely cold weather, we strongly advise you to keep the temperature constant both day and night. If a furnace or heat pump is trying to recover in the morning during a cold snap, it will have a difficult time getting to the temperature that you want it to be at. The reason is because not only are you heating the air in the home, but you’re also heating the walls, furniture, floors, and all other objects in the home. Once those items get cold, the heating system is going to have to constantly run to warm them back up again, which will end up costing you more money in the end and will provide less comfort within the home.