The upgrade to 1.26 introduced temperature and moisture effects that the player has to deal with. If you wish to build a house in the colder biomes, you will need to provide some heating so your character does not freeze to death. You could constantly wear heavy furs and replenish them since they wear out fast. Or you could build fires in your living areas.
To heat a smaller area without walls, a basic fireplace can be used. This can be as simple as a few blocks removed from a (non-flammable) wall with a burning coal block inside. It can be the central focus of a larger room as well. It could be a traditional looking fireplace, or it can even be hidden from view.
This is an example of the most basic indoor fire. The glass blocks protect the character from catching fire. It is not very efficient but works well enough for small rooms.
This is an example of a firepit style fire. Again, the glass blocks are to protect the character. The spaces between the limestone must be left open to let the heated air out.
This is an example of a fireplace in a house. All materials used in the fireplace and surrounding it are not flammable.
Here is an example of a 'hidden' fire. The actual fire is in the room below this one. The hole in the wall (and floor) allows the heated air to enter this room. As long as there is an air path from the fire into the room, it will be heated. The fire does have to be close enough to the room to heat it properly, too. That means no more than 30 blocks from the farthest corner in the room.
It is very important to be careful where you make your fire. You can easily burn down your entire house or a forest, if the fire gets out of control. A small fire can ignite blocks on the other side of a wall, 2 blocks away.
I (Stanimus) have recently done some extensive testing on the heating effects of fire and have some interesting conclusions. For the full report, see my blog. Here, I present one of the more exciting results - you can build a hot-air furnace and run ductwork to heat your house!
This lets you put doors on your rooms without cutting off the heat supply and you don't have to put a fireplace in every room.
The first thing you need to know is that a fire will heat a sealed area up to 30 blocks from it. At 30 blocks, you will have a temp of '5' (on the thermometer) even when the outside temp is '0' or lower. At 10 blocks or less, the temp will be at least '8'. A '5' is warm enough to keep you from freezing even without clothing on, so you can have a reasonably sized house and heat it from just one fire block.
Any room within this 30 block sphere will receive heat from the fire IF there is at least a one block air path between the room and the fire. The actual length of the path is not critical. This lets us use ductwork to connect to the heat source. The room will be heated almost as well as if it had a direct, line-of-sight path to the fire. If you are concerned about leaving an opening to each room, you could place a door at the opening and only leave it open when you wish to heat that room. Unfortunately, a trap door will not work. It seems the game still regards a trap door (or fence gate) as a seal - open or closed.
The hot air furnace needs to be designed properly for the best results. You need a space at least 3 x 3 blocks and 2 blocks high. Place the coal block on the floor in the center and light it. Connect your ductwork to this furnace at the same level as the fire block, not the coal block for the most heating.
Careful layout of your house will let you put your ductwork so nobody can tell it's there. For instance you can run it in the floor, in the block directly under walls. Then if you leave out just one block at the bottom of that wall, it will create a heat vent to the rooms on either side of that wall.
If you have a corner where 4 walls meet, the duct can be run up (or down) through the very corner and the walls will hide it.
The duct can weave around as much as you need as long as it stays inside the 30 block radius.
- Almost every placed item will block air flow, even if it is not a full block in size. Doors will block air flow when closed but allow it when open. Trap doors and fence gates will block air flow whether open or closed.
- Carpet and snow will block air flow so be careful when using heat vents. If your vent is at the bottom of the wall and you place a carpet right in front it, you will prevent the heat from entering the room.
- Glass will allow some heat to pass through it. With a solid glass wall around a fire, you can still get heat from the fire to about 3-4 blocks away from it.
- See also Body Temperature.