Contrary to common belief, closing off a room can actually make your heating less efficient. When interior doors are kept shut, the pressure in the room increases because the flow of air is now blocked.
The simple answer is, leave them open.
You see, when an HVAC system is operating, it functions best as a whole unit, circulating air throughout your entire home. So, when you shut several doors in and around your home, you're actually disrupting the nature of how your HVAC system operates.
During the day, it's best to keep your windows and doors shut in order to keep the hot air from entering the home and keep the air circulating with fan.
Contrary to popular belief, closing your bedroom doors does not improve the efficiency of your HVAC system and may actually increase your utility bills. When you close a bedroom door, you effectively block the air's pathway, and that blockage can lead to issues with airflow.
In light of all these situations, the best thing to do in order to maintain the efficiency of your HVAC system during the winter and summer months is to keep your interior doors open. Proper air flow will allow the HVAC system to work at optimum capacity.
Closing a bedroom door reduces the air flow into the room and the air flow through the system. When the system puts air into a room and it gets trapped, it pressurizes the bedroom. This positive pressure forces the cooled, or conditioned, air out of the house through any opening in the room that the air can find.
When you shut a door, the air that's still blowing out of the vent builds in the room, pressurizing it. At the same time, the return is making an extra effort to suck in enough air to cool the entire house (not just the rooms with open doors).
The ideal thermostat temperature in the winter is 68 degrees Fahrenheit when you're at home. Energy.gov suggests that 68 degrees is a good room temperature while you're awake at home but recommends lowering it while you're asleep or away.
Opening the windows simply lets cool air escape and hot air to enter, resulting in hotter interiors. Before deciding to open all your windows at home during hot weather, grab a thermometer, and check if it's hotter outside the house. If it's cooler indoors, just close your windows.
Research from UL's Firefighter Safety Research Institute (FRSI) shows that closing your bedroom door helps prevent a fire from spreading, lessens smoke damage and could even save lives. Just like having the right homeowners insurance, a little preparation can go a long way to help you rest easy.
You might think that it's a good idea to have the window open and let in some fresh air. But in actual fact, you should definitely keep your windows shut and shades drawn during the hottest part of the day, according to the NHS.
3% of Your Home's Lost Heat is Through Doors
You can find doors that are Energy Star Rated here.
The lower the temperature is inside of the home, the slower the rate of thermal energy loss. To achieve optimal comfort, it is recommended for homeowners to set their thermostats between 68 to 72 degrees while there are people inside of the home.
Set your thermostat to 68 degrees Fahrenheit in the winter
According to ENERGY STAR, setting your thermostat to 68 degrees Fahrenheit (20 degrees Celsius) when you're home is the ideal balance of comfort and energy efficiency.
To maximize efficiency, it's best to keep your furnace (or AC) at the same consistent temperature for long periods of time.
Many homeowners think it's a good idea to close air vents in unused or infrequently-used rooms during the winter months in order to save money on heating. Should you do the same? The short answer is no. As a matter of fact, doing this can lead to the need for a home furnace repair.
Closed doors don't allow the conditioned air to circulate throughout the house, creating uncomfortable hot and cold spots throughout.
The first is to check your vents. You might have heavy furniture or items covering up your vents, absorbing all the heat. This is a very common reason why one room in a house is always cold, and it's easily solved by simply moving the items away from your vents, allowing an unobstructed flow of warm or cool air.
When you are done baking, it doesn't hurt anything to leave the door open when you turn it off. All it will do is add some heat to the thermal mass, whether it's all up at the ceiling or not, it's still in the room and helps even if just incrementally. Highly active question.
On inspection, you'll be able to see how much insulation there is, and possibly what type. Looking up your type of insulation will allow you to determine if it should be replaced or increased in its R value. A home energy audit may find that the walls are actually the most significant cause of heat loss in your home.