Should the shed (home of the heater) have its own radiator?

[Garald]

Works proceeds apace. The heat-pump is being installed - no surprises so far.

 

Question. The internal unit of the heat-pump (DHW included) will sit in the following space. Formerly a small garage, it will now be a bike shed/storage space/technical room; we'll replace the outside metal door by a wooden door. Should we also put a small radiator in that space?

 

 

I imagine the heat-pump's internal unit and the water heater:

- have a certain minimal ambient temperature they need to work (that being what? 5C? I can't find it in the documentation)

- emit some heat to the ambient air (but perhaps not much).

 

Given the solid wooden door, the fact that the garage is under a heated space (my living room), bounded by an inhabited space (a GP's office) on one side and the coop's corridor on the other, etc., it seems sensible to assume that its temperature will be very, very roughly the arithmetic mean of the inside temperature and the outside temperature.

 

In other words, if I heat to 20 C, and the outside temperature is -10 C (a rarity; that happens only every few years - the Eurostar grinds to a halt, etc.) then this place will be ca. 5 C, which is roughly OK. On the other hand, if I am away on a trip and set the house to be heated to 10 C in my absence (sounds safe, right?) then the garage will be at around 0 C when it is -10 C outside. Then it does seem sensible to put a small radiator.

 

Am I being naïve or estimating anything wrongly?

[gaz_moose]

sounds like you have answered your own question.

you could always just plug a 1KW fan heater in set to frost protection if you were leaving the building empty over the winter months and was worried.

[DanDee]

11 hours ago, Garald said:

Works proceeds apace. The heat-pump is being installed - no surprises so far.

 

Question. The internal unit of the heat-pump (DHW included) will sit in the following space. Formerly a small garage, it will now be a bike shed/storage space/technical room; we'll replace the outside metal door by a wooden door. Should we also put a small radiator in that space?

 

 

I imagine the heat-pump's internal unit and the water heater:

- have a certain minimal ambient temperature they need to work (that being what? 5C? I can't find it in the documentation)

- emit some heat to the ambient air (but perhaps not much).

 

Given the solid wooden door, the fact that the garage is under a heated space (my living room), bounded by an inhabited space (a GP's office) on one side and the coop's corridor on the other, etc., it seems sensible to assume that its temperature will be very, very roughly the arithmetic mean of the inside temperature and the outside temperature.

 

In other words, if I heat to 20 C, and the outside temperature is -10 C (a rarity; that happens only every few years - the Eurostar grinds to a halt, etc.) then this place will be ca. 5 C, which is roughly OK. On the other hand, if I am away on a trip and set the house to be heated to 10 C in my absence (sounds safe, right?) then the garage will be at around 0 C when it is -10 C outside. Then it does seem sensible to put a small radiator.

 

Am I being naïve or estimating anything wrongly?

 

If in the space where the heat store is placed is too cold, you don't need a radiator, you need to insulate the space so you don't loose heat, rather than waste even more.

[Garald]

23 minutes ago, DanDee said:

 

If in the space where the heat store is placed is too cold, you don't need a radiator, you need to insulate the space so you don't loose heat, rather than waste even more.

 

So the answer is: 

- wait until it is a problem

- if it is ever a problem, put a conventional heater in front of it at the worst of times, and insulate the door better? (And/or the wall with the unheated corridor, but I doubt that the corridor will ever get cold enough for the internal unit to stop operating. What is the minimal temperature of these things?)

 

I'd rather get all work done, while the workers are still around, though.

Edited March 22, 2023 by Garald

[JohnMo]

1 hour ago, Garald said:

wait until it is a problem

No make sure every pipe is insulated ideally with at least 25mm thick insulation.

 

I would also look to box the lot in an insulated box, so any heat leaking out of the cylinder and or piping is contained and forms a warm space for it to live in.  Then who cars about the the rest of the room space.