Air source heat pump

Crazy Harry said:
I want to build the heat up so all the machines are warm as well - so I'm not working the lathe with the gearbox full of cold / stiff oil for example or the metal stock I'm using are like blocks of ice to hold - and I'm sick of lying on a cold floor at my age let alone the fact its often too cold to paint. Spot heaters are fine until you move and you can end up with one side of your work hot and the other cold. To my mind constant low level heating will provide a happier working environment. I've read a few sales pitches for air source and they talk about £250 /£300 electric use. I'm sure conventional heating by oil or electric is going to be more than that.

Forgot to say I'm retired so some weeks in autumn and spring I can spend days on end in the workshop.
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A heat pump air conditioning unit to "just take the edge off" is not really the way to go. If it is undersized, it will just run flat out all the time as will try to achieve a set temperature. Also you won't get a small one installed for less than £1500 plus running costs. You could buy a lot of electricity for that!
Are you able to put a wood burning stove in? If you have an outside wall you should be able to. I put one in my last garage, bought from eBay for £100, fitted it myself. Burned excess wood. It was brilliant. You also don't have to get any approval for them as they are not installed in a habitable space!
 
Pondrew said:
Crazy Harry said:
I want to build the heat up so all the machines are warm as well - so I'm not working the lathe with the gearbox full of cold / stiff oil for example or the metal stock I'm using are like blocks of ice to hold - and I'm sick of lying on a cold floor at my age let alone the fact its often too cold to paint. Spot heaters are fine until you move and you can end up with one side of your work hot and the other cold. To my mind constant low level heating will provide a happier working environment. I've read a few sales pitches for air source and they talk about £250 /£300 electric use. I'm sure conventional heating by oil or electric is going to be more than that.

Forgot to say I'm retired so some weeks in autumn and spring I can spend days on end in the workshop.
Click to expand...

A heat pump air conditioning unit to "just take the edge off" is not really the way to go. If it is undersized, it will just run flat out all the time as will try to achieve a set temperature. Also you won't get a small one installed for less than £1500 plus running costs. You could buy a lot of electricity for that!
Are you able to put a wood burning stove in? If you have an outside wall you should be able to. I put one in my last garage, bought from eBay for £100, fitted it myself. Burned excess wood. It was brilliant. You also don't have to get any approval for them as they are not installed in a habitable space!
Click to expand...

I thought about another oil fired system; and a wood burner but they both take up valuable space where I could get a machine in - and I've seen some close calls with volatile fumes igniting when idiots weld and that also puts me off having a stove with an open flame. I was looking at an air source heat pump at around £3-4K until I read your posts at the start of the thread. I have a nice south facing wall that traps warm air close to the building. I also liked the notion of being a little more green - payback for all the gallons of petrol I've burnt over the years commuting and having fun.

The intention was to starting heating the workshop in late summer / early autumn and maintain that through to spring so its always warm (I liked the option of the inverter AC cooling it in summer). It doesn't have to be hot like a house otherwise it would get unbearable doing physical work. Its 3m x 9m single story with open roof void.
 
ronk said:
I am giving serious consideration to going down the ASHP route to replace my 19 year old conventional gas boiler - Has anyone else on here done it and with what results please?
I would like to know, warts and all - I would rather believe users than the advertising blurb :thumbsup:
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Why does it need replacing? Ours is 25 years old and still runs ok. We have had a couple of faults in the 19 years we have lived here and they were fixed for a reasonable price. Other than that the motorised valves sometimes go but I keep a spare and can do that job myself. Even if the heating isn't working we can heat the hot water tank as it has an immersion heater.
 
"It's like if you stuck a moped engine on a shopping trolley, it could be marketed as the most fuel efficient roadster." :rofl:
 
Very interesting discussion though as I have plans to build something so was thinking of ground source heating.
 
pvr said:
Very interesting discussion though as I have plans to build something so was thinking of ground source heating.
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Ground source is good. You need a lot of outside space to sink the pipework, though. and a lot of groundworks/ excavations and backfilling.
There have been cases of people just going "down" with ground source to keep the area to a minimum. This doesn't work either. It's all to do with the subsoil below about a metre being a constant 10-15 degrees c.
 
It's very simple thermo-dynamics, really. To heat something (anything), you have to get that heat from somewhere. If you can transfer that heat from a reliable and sustainable source, then it's all good.

Energy cannot be created or destroyed. It can only be changed. A superb example of this is the ICE.
 
Pondrew said:
pvr said:
Very interesting discussion though as I have plans to build something so was thinking of ground source heating.
Click to expand...
Ground source is good. You need a lot of outside space to sink the pipework, though. and a lot of groundworks/ excavations and backfilling.
There have been cases of people just going "down" with ground source to keep the area to a minimum. This doesn't work either. It's all to do with the subsoil below about a metre being a constant 10-15 degrees c.
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Space is not an issue, just cost versus benefit really. How far can the groundwork be from the building as I would rather dig up a field then the garden.
 
pvr said:
Space is not an issue, just cost versus benefit really. How far can the groundwork be from the building as I would rather dig up a field then the garden.
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It doesn't really matter, as long as you have a big enough pump to circulate the water. If you run the pipework on the surface from wherever it's going to be submerged to the building, though, you will see it and it will have to be super-insulated to maintain any kind of efficiency. If you bury the flow and return (ie just a strip of digging) it would add to the efficiency therefore your heat transfer area would be smaller.
 
pvr said:
Space is not an issue, just cost versus benefit really
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The cost will be quite high, unless you have access to a digger and can excavate and backfill yourself. Also, the deeper the pipework, the better.
 
I will expense the cost against the business as it will be another office building. Just want to keep the running costs down as my electric bills are already £200 a month for running the equipment.
 
pvr said:
I will expense the cost against the business as it will be another office building. Just want to keep the running costs down as my electric bills are already £200 a month for running the equipment.
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You could try a mole plow, just tow it behind a tractor and it will lay the pipe below the ground, with little disturbance :thumbsup:
 
Hello. I have seen a second hand, 7kw Fujitsu air con split unit for sale for £175 which appears to be enough to heat my home office . Can I ask if you think it’s worth pursuing this (finding a suitable fitter) please? I want it to keep warm in winter/ cool in summer. I have GCH but try to keep it to a minimum during the day when it’s just me at home. The room is on the side of the house and it could be fitted on the garage flat roof below.
Appreciate this may be a ‘how long is a piece of string’ question .
Thank you
 
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