Air source heat pump feed back

googlefast

Mintyrbc said:

I would research makes of heat pump, for £11k id be wanting a Dakin, Viessmann or Mitsibishi with a decent sized cylinder containing an inline buffer for that sort of money.

That cylinder looks massive, how many litres is it? The quote I've got is for a Grant unit, I don't think I'll be upgrading our heating system anymore, our renewal quote for leccy is 15p per kw, it was around 12.5p before!

googlefast

shinytop said:

googlefast said:

Mintyrbc said:

What system have you been quoted £11k for? I can tell you if they quote is a rip off.

The quote is just for a basic installation of 10kw condenser, plus the cylinder and the bare minimum of what's needed to make it run. They aren't making any changes to the pipes, radiators, or anything really, just connecting the new system to the old radiators, their quotation does mention 4k for labour though.

Here's what I've found out so far, apparently the company that manages the GHG scheme is rejecting some quotes and saying that they're not realistic, that's what I heard from one company. It's a shame really because the idea behind scheme is great, but the implementation of it and being able to only work with a few hand picked companies just makes it not fit for purpose.

That sounds a lot.  I've had 2 quotes for a 14kW Mitsubishi heat pump, cylinder, and a full system with all controls including 12 rads and pipework both 16-17k. My house is very easy for pipework and wiring being a bungalow but still... 

I had a feeling that I was being ripped off! Are you going ahead with the installation?

matelodave

Don't even think about just hanging it off the existing plumbing and radiators unless you get some guarantees regarding heating and efficiency performance. Anyone who is just offering to replace a boiler with a heatpump without doing a proper system evaluation should be avoided at all costs

Rads for gas or oil systems are usually sized for a flow temps or around 60-70 degrees and heatpumps just don't perform well at anything above 50 (ideally you want it down to around 40 to avoid compromising efficiency) so your rads, and possibly some of the plumbing, needs to be sized to perform at lower flow temperatures - that means rads at least 50% larger than the ones you've got.

Trying to run a system at high flow temps will cost you a lot of money, especially if you crank it up so the backup/boost heating has to be activated. This is one of the biggest causes of dissatifsaction with ASHP. You'll be both cold and skint.

Mintyrbc

googlefast said:

Mintyrbc said:

I would research makes of heat pump, for £11k id be wanting a Dakin, Viessmann or Mitsibishi with a decent sized cylinder containing an inline buffer for that sort of money.

That cylinder looks massive, how many litres is it? The quote I've got is for a Grant unit, I don't think I'll be upgrading our heating system anymore, our renewal quote for leccy is 15p per kw, it was around 12.5p before!

Its huge, i had to cut the ceiling out of the plant room a bit too fit it in. Its 250L hot water with a 90L buffer for the heating on the top so 340L in total. I have young kids so go through loads of water every day so needed the capacity.
It's a point people don't realise, you need space for all the kit. I was lucky, mine is in what was an old outdoor toilet, I tiled and insulated it and ran electric to it and turned it into a tiny plant room. I could never have that in my house, it would take up way too much space. 

shinytop

googlefast said:

shinytop said:

googlefast said:

Mintyrbc said:

What system have you been quoted £11k for? I can tell you if they quote is a rip off.

The quote is just for a basic installation of 10kw condenser, plus the cylinder and the bare minimum of what's needed to make it run. They aren't making any changes to the pipes, radiators, or anything really, just connecting the new system to the old radiators, their quotation does mention 4k for labour though.

Here's what I've found out so far, apparently the company that manages the GHG scheme is rejecting some quotes and saying that they're not realistic, that's what I heard from one company. It's a shame really because the idea behind scheme is great, but the implementation of it and being able to only work with a few hand picked companies just makes it not fit for purpose.

That sounds a lot.  I've had 2 quotes for a 14kW Mitsubishi heat pump, cylinder, and a full system with all controls including 12 rads and pipework both 16-17k. My house is very easy for pipework and wiring being a bungalow but still... 

I had a feeling that I was being ripped off! Are you going ahead with the installation?

Yes I am.  Our house is quite well insulated and we're getting new doors and windows anyway.  We have no mains gas so the alternative would be to stick with/renew storage heaters or install oil CH.  The system can be designed for the ASHP and the RHI (I will get the maximum) plus likely savings vs storage heaters and various electric heaters make it worth a try.   

I'm not using the Green Homes grant though; I have a suspicion prices are inflated by suppliers when you do.  If you want any more details of my quote PM me.