I don't think I understand heaters

[loki_racer]

I have a small colony, all enclosed with walls and a single exit door.  I have plenty of power and batteries and 5 heaters.

All my prisons freeze to death.  What am I not understanding about heaters?

I have tried setting target temps to anything from 20 C to 40 C.

[Tynan]

Ensure the room is actually enclosed. That means the roof too!

[loki_racer]

Ya, I double checked that.  Is a floor required?

[Tynan]

No floor needed.

When you mouse over the room, does it say 'indoor' in the bottom right of the screen?

[loki_racer]

Here's a more advanced building I have going: http://imgur.com/a/kHNMr

[Tynan]

From the look of it, that interior space should be enclosed.

[cliodne]

You might want to equip each bedroom with a heater as well.

[Zerohero20]

For a room that size I had to use around 10 heaters to keep it stable and warm. Just add more heaters to see if that works.

[DaNewb]

I understand its a large room but he has three heaters and a cooler that has heat pumping into the same room.  There is no way that room should be -2 degrees...

[Drahkon]

The main room shouldn't be -2, but I can't see where the mouse is. Those sub rooms have no heaters and are closed off, they could be -2.