Why does it still get hot indoors in the cool months?

I've always wondered why when it's in the 50's or 60's outside it can still get hot inside if you don't open a window?

Is it the heat from appliances, lights, and electronics?

 

My house has shitty insulation so its usually the same temp inside as it is outside unless we have the air or heat on.

If your home gets a lot of natural light and its a sunny day its probably due to heat from the sun. Otherwise I dunno lol, just good insulation?

 

if you are in one of the upper floors of your building, it could be that the heat is rising up

 

The greenhouse effect. Heat from the sun gets trapped. Kind of like my car sitting in the sun right now that I have to drive in a few minutes. It's probably about 120f inside.

 

Lights and appliances do generate heat, so does your body so if there's a cold room and you fill it with several people it will inevitably heat up.

 

some buildings have furnaces.

 

A generally guess of the energy effeciancy of a product can be made through how much energy is lost through heat. You remember how hot old school incandescent light bulbs got. Some of it is due to the heat from electrcity and some to do from the greenhouse insulative effects.

 

I always thought that my computer had to contribute to a lot of it, when my computer is mining dogecoins its like a little heater almost.

I suppose the heat just can't escape fast enough since it's not really "cold" outside. I think it probably takes a while for all the heat in the walls and stuff to seep out too

 

This house is heavily insulated, so insulation holds heat a long time. Maybe your building is, too.
The upside of that here, is that heat does not escape so easily in winter and cold months.....but it is too hot in this house in the hot months. I also hate humidity.....

Some things and materials hold heat longer, as well.

 

the people downstairs grow weed..

 

insulation also helps to keep the cold in, or rather the heat out also. it helps the room maintain whatever temperature it is. thicker insulation is better i just couldn't imagine that appliances and lights could add that much heat but this is the top floor so i'm sure even when my heat is turned off that heat from the other apartments seeps up here.

there's also a steam pipe that runs through my kitchen for heat, but there's no way to turn that off so whenever the boiler in the basement decides to let steam out, it heats up.

this building was built in the 40's i think, so i wouldn't think it would be insulated that good but they've probably done some upgrades over the decades