Tim Lamb wrote:
In message ,
Capitol writes
Tim Lamb wrote:
In message ,
Capitol writes
John Rumm wrote:
I find fully electric in a 17' x 12' workshop that is fully lined
with 2" of PIR foam to be relatively cheap. I have a wall mounted
fan heater with an external stat to keep it about about 5 deg. I
can turn that up when I am using it, and also supplement it with a
standalone halogen heater. Only really needed for 20 mins to get
the place to a comfortable temperature, then the fan heater will
maintain it.


I use a heat pump.

Kindly expand..

I briefly considered an air source heat pump for my carpentry
tenant. AFAIR for around 1000ukp I could get his partitioned off
office up to a reasonable temperature.

Heating the remaining 120 m2 was out of reach. Intermittent
occupation did not help. Ideally something over 10deg.C for gluing.

Currently he is exploring electric fan heating spread across 3
phases. The roof has 75mm of PIR foam but the walls are 4" block.
Internal insulation would be extremely disruptive and external
leaves the thermal delay of heating the walls.

This is a 12K btu aircon unit which puts out 3.6Kw nominal
with a nominal efficiency of 300% into 7 x 20 x 20 ft. The floor is
uninsulated, the walls have 1" of glass fibre insulation, topped by
1/2" ply, with bubble insulated metal doors. The ceiling has 4" of
glass fibre under 1/2" plasterboard, topped by 3/4 inch plywood. Plus
all the rubbish stored in the loft in case it is useful! It takes
about 1/2 an hour to heat up to 26C with 5C outside temperature..
Also useful for perhaps 1 day per year as air conditioner!

That's impressive. How much?

I paid about £230, some years ago. I think the best going price
for a similar unit now is around double that. Many hotels and pubs are
now using these units to reduce heating costs without requiring boiler
installations and oil tanks. Secondhand units can be found for about
£100, but will require regassing. Should be less than £100 for the
service. Cars are £50-85 for the service.