How did people keep houses warm 100 years ago?

Hundred years ago, the world was not like nowadays, as the electricity was limited and heater wasn’t invented yet. Therefore, to keep their houses warm, most of them chose to use the natural resources and widely used the advantages of their physical environment. How did the people keep their houses warm hundred years ago when all they had was fire and sunlightas a source of heat energy? the fire transfers heat to the rest of the room by convection.

Hundred years ago, almost every house had a big fire place and long chimneys with black smoke coming out during winter when it is cold. People chop down trees and cut them into small pieces so they can burn them during winter when it is cold. Air inside the house is heated up by the fire and it rises because hot air has a less density because particles move around faster and further away from each other. later, as the air cools down, and gets heated up again. That is how a fire place work and that was one of the major ways people kept their houses warm 100 years ago.

another source of heat energy they used was solar energy. People who lived in countries experiencing cool temperature 100 years ago painted their houses into dark colors. As the sun radiates down radiation, dark colors can absorb heat more efficiently than light colors. Dark colorsdoes not reflect sunlight like light colors, instead they will absorb.
so radiation from the sun is converted to heat energy after been absorbed, and this warm the houses. Result in the change of room temperature.

People built their houses
with large amounts of glasson the south side, for the full capture of sunlight in day time. During night time, they would close the thick curtain to prevent rapid heat lost. Windows shut off properly can reduce all three kinds of heat transfer which are convection, conduction and raidiation. To achieve this, some of the people used cement to fill the gap in between the window frames, for reducing air flow. And this which can reduce heat loose.The other way is to create a thicker glass, this increase insulation and reduce heat loose from conduction.

The walls are thick for heat to soak up then slowly radiate into the houses, also to reduce heat from moving out. Because of the heat soaked inside the thick walls during daytime, the heat will still continue to radiate in during night time. When its morning, the walls are totally cooled and they get heated up again by the sun.

other than this, people built their houses with double walls. they could have concrete wall on the outside and a wood wall inside. Since air is a good insulator, this could help to reduce heat loss and most importantly it does not require electricity.

Some ancient people even have floor heaters, of course those were different from what we have today. The general idea is that there was a large stone under a living space. And then smoke from cooking used fire is trapped under the stone and goes to the other side. Heat in the smoke heats the floor up by conduction and when it gets hot enough we are able to actually feel it. The advantage was that even if you remove the direct source of heat, there still remains the heat, it was a long lasting system. But the danger was if the floor cracks causing the floor to have a gap, the smoke can rise up and cause 'carbon monoxide poisoning'. adding to the disadvantage, the floor would only heat up when people are cooking and people usually do not spend a whole lot of time cooking all the day so the floor heater might not be really useful. Still many people would chose this way to heat their houses as this didn’t need to pay extra money. The heating source is from the fire you use to cook. Why are they having heaters on floor rather than on ceiling? This is because, hot air rises and cool air sinks. If they have heaters on ceiling, the results will not as efficient as having them on the floor. When you having heaters on the floor, you will not feel temperature change that much as the air is doing convection continuously. Hot air is rising while cool air sinking.

although the ways to insulate their house are limited by the technology and resources they have, people still managed to get their houses as insulated as possible 100 years ago.