Keeping warm in the house during Winter — Radiative Heat Loss

It’s that time of year when discussions about “what temp do you keep your house” pop up on this sub.

In one camp, you have folks who set their thermostat below 70, and in the other camp are folks that set their thermostat above 70. All of us have lived with others who prefer a different temp than our personal preference, so there is an amicable and shared understanding that we each have differences.

I’d just like to remind folks about some reasons why your house may feel colder in the Winter despite maintaining the same temperature as the Summer months, AND what you can do about it.

1. Radiative Heat Loss: Everything emits thermal radiation (including us). During the Winter, the objects around us cool – for example, your windows – go touch them right now. They are probably very, very cool/cold. Also under/un-insulated patches in your exterior walls. Your flooring on ground floor. Any surface with clear line of sight to your body that is cooler than you will pull thermal energy from your body. This is the biggest factor.
2. Heat index: A function of temperature and humidity. Colder weather = less humid = lower heat index. Less of a factor than #1.
3. External factors: During Winter, your house does not benefit from heat sink (heating of house/external), and cold winter air (convection) can enter your home depending on air tightness (ACH – air changes per hour).

So what can you do?

1. Layer. Put on long pants and long sleeves. Wear slippers. See #1 above – add buffer between the radiative heat loss. This is easy, and simply put the most effective solution to “feeling cold”.

Higher cost/more effort options:

1. Seal your house. Check door seals (weather stripping), add door sweeps. Blower tests will measure “air tightness” of your home, but this will only inform and not fix your issues.
2. Insulate where you can. ie, in crawl spaces/attic of your home. Ground flooring is a major contributor of heat loss.
3. Add a rug if your floors are cold. Cold floors will pull heat from your body very quickly.
4. Circulate air on your home if there are cool/warm spots. Use a fan.
5. Crank the heat

I won’t get into double/triple pane/low E windows as no one is going to shell out that much money.