Gshp diy/selfmade

[Patrick]

Hi,

 

Thinking about heating atm and a Gshp is quite nice, but seems outstanding expensive. I get that it just cost a certain amount for someone to install it for you.

But if you have a digger on site, what's stopping you burying a few hundred meters of Pex pipe in 1-2meters depths and connect it to a Gshp unit yourself.

maybe even let a professional connect it and calibrate the system.

I seen 10kw units for 1000£ and Pipework is something around 0.5£/meter.

The antifreeze-water mix that goes into it is around 250£ for a 350m pipework.

That's a lot less then the often quoted 10.000-15.000£ for Gshp.

I wondered if any of you have done this himself and if it was successful and if not what where the problems.

Digging a whole and sinking a cable shouldn't be the problem, but if that isn't, what is?

 

[hallega]

We are about to install GS in about 2 months time. My husband is reluctant to dig the trenches and install the pipework himself even though we have the diggers etc., I know you have to be careful when you backfill the pipe in case there are any sharp stones and so sand is put over the pipes. spacing is important too. I did see one bloke who put it in himself somewhere on line and he had trouble with frost, I think he put them too close together and it didn't work. We will get back quite a bit of the money over 7 years from the government, plus it won't cost us £3000.00 a year in oil costs, the new house will be insulated up to the max.

Personally I'm all for DIY but in this case not...yes it's expensive, putting in the UFH pipe looks a doddle, so maybe we will attempt that and also the pipework for the MVHR.

You also get conflicting advice as to what size boiler, we have been told 8kw/10kw/12/kw and 18kw.....goodness it's a mindfield out there. Gone for the 12kw with an option to switch to a pool if we ever get around to it. 388sq m house but again loads of insulation, fingers crossed it works! Going for straight pipes not slinkies, better we think.

[joe90]

If you read threads on here it appears ASHP,s are a better bet than GSHP,s. I have the room and machines to instal my own GSHP but went with an ASHP (self instal) and it was soooo much easier. I am sure others will chip in soon.

[Jeremy Harris]

Very true, @joe90, we were originally going to install a GSHP (it's on our planning consent) but switched to an ASHP when I looked at the whole life cost, which was astronomical when compared with an ASHP.  The cost difference was massive, around £2k for the ASHP versus around £8k for the GSHP (both installed cost).  The tiny difference in theoretical efficiency (which almost certainly wouldn't have been real in practice, due to collector loop pump running cost over the year) would never have come close to making up for the massive difference in initial cost, let alone the ongoing servicing cost that a GSHP invariably incurs.  We could easily fit three replacement ASHPs over the next 30 years or so and still come out on top, although I don't envisage having to do this, as the ASHP just does it's stuff and works, needing no attention other than cleaning cobwebs out of the grill every year or so..