Build a heated room in a cold storage

[gaidin]

I have an isolated storage unit that I don't heat, but I want to build a heated room inside the unit for storing things like a pressure washer and other items that need to be kept above freezing. I simply want to save some energy by only heating 10m2 instead of 25.

My plan is to frame up a wall with 45x70mm studs, insulate, and cover with panel material.

Am I thinking correctly when I consider the following?
12mm chipboard on the cold side, 70mm insulation, vapor barrier, and then 12mm chipboard again on the warm side.
A storage door for the heated storage room.
In the room, there will be a small wall-mounted heater with a plug connection.

Do I need an air gap? Any material inside the chipboard on the cold side?

 

[klaskarlsson]

I would have constructed it the same way as an exterior wall. Then I prefer a vapor retarder instead of a barrier, so that any moisture that might get in can also get out, and if it is not constantly heated, the dew point can be reversed, but with so little insulation, it probably matters less.

 

[gaidin]

I would have constructed it the same way as an exterior wall.
Then I favor a vapor retarder instead of a barrier, so that any moisture that can get in can also get out, and if it's not constantly heated, the dew point can be reversed, but with that little insulation, it probably matters less.

Thanks for the input.
When you say exterior wall, do you mean wind barrier on the cold side? Or maybe a vapor retarder on both sides?
There's no "weather" on either side in terms of wind or rain.

 

[klaskarlsson]

Thanks for the input.
By outer wall, do you mean wind barrier on the cold side? Or maybe a vapor brake on both sides?
There won't be any "weather" on either side in the form of wind or rain.

Träguiden has a good recommendation.
You don't need to build double protection of course, so "panel" for example is skipped. But at least two of the walls become like outer walls if I understood it correctly? The others become like insulated inner walls?

https://www.traguiden.se/konstruktion/konstruktiv-utformning/stomme/vaggar/yttervaggar/

 

[gaidin]

Träguiden has a good recommendation.
You don't need to build up double protection, of course, so "panel" etc. can be omitted. But at least two of the walls will be like exterior walls if I understood it correctly? The others will be like insulated interior walls?

[link]

I will partition the storage with a wall so there will be three exterior walls and one wall that borders the cold part of the storage.

I will check out the guide, thanks!

 

[Weimik]

Isn't it a bit overkill to make an additional outer wall? I think a regular insulated inner wall is enough. There is wind barrier paper in the existing outer walls, and a vapor barrier shouldn't be needed when there is only 70 mm insulation and presumably relatively little moisture if it's only used for storage.

 

[gaidin]

Isn't it a bit overkill to make another outer wall? I think a standard insulated inner wall is enough. There is wind barrier in the existing outer walls, and a vapor barrier shouldn't be necessary when it's only 70 mm insulation and presumably relatively little moisture if it's just used for storage.

Furthermore, there will be a couple of ducts for natural ventilation so the rest of the storage gets some residual heat; I don't want it completely unheated.

However, it can get humid with standing pressure washers, water hoses, etc., but only temporarily in the fall when I put things away.

 

[Weimik]

However, it can get humid with constant pressure washing, hoses, etc., though it's probably only temporary in the fall when I put things away.

I believe a vapor barrier is normally needed to handle moisture from humans. A human emits about 2 liters of water per day, so the moisture from items you store in the shed should be negligible in this context.