Hybrid Heat Pump Trial

spinaltap

Distinguished Member
If you reside in the West Midlands, British Gas are looking for suitable customers to trial a Vaillant Hybrid Heat Pump in their home. It will be monitored over 2 years.

They will cover 70% of the installation cost - and you will be entitled to RHI payments too.

 

Daniel 70

Active Member
Having had a Heat pump system in a DIY hybrid configuration for about 5 years now .. No experimenting it just works. I got the house rebuilt in about 2007 and while I had requested a pellet burner, my builder convinced me otherwise. ..and put in an oil burner . So mixed radiators and underfloor and oil burner with mixing valve etc all in place. Eventually I got a Heat pump installed in parallel . There was some complex mixing blending valve put in by the installer to allow the oil burner come on under certain circumstances. Unfortunately the combination was not greatly successful. I then basically removed the blending valve and connected the oil burner in series with the heat pump with the flow going from the heat pump into the oil burner and then into house system and the return water going into the heat pump. That way any very hot water from the oil burner went directly into the house, and protected the heat pump. I added more insulation around the boiler .. except at its air intake.
Bottom line .It works a treat. My stats are that the heat pump has run for 17,000 hours .That is the compressor heating water ,and the oil burner for 92 hrs . So as you might imagine, the oil fills are very rare. The oil burner and boiler adds mass and thermal capacity to the heat pump system, so it has less frequent starts and stops .
The major trick with a heat pump is to try and reduce the average temperature that it needs to heat the water to, and this means reducing as far as possible all thermal barriers in the spaces you want heated. .. So all radiators full on, all floor heating full flow. .. Counter intuitive yes .
 
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spinaltap

Distinguished Member
British Gas surveyed my 1975 built home to determine its suitability for the trial.

If selected, all my radiators would have to be replaced with K3 (triple panel/convection) radiators. If not for their discount, this alone would cost the equivalent of replacing a condensing boiler.
 

niceguy1966

Well-known Member
British Gas surveyed my 1975 built home to determine its suitability for the trial.

If selected, all my radiators would have to be replaced with K3 (triple panel/convection) radiators. If not for their discount, this alone would cost the equivalent of replacing a condensing boiler.
Good luck, it sounds interesting, and you'll be getting everything at a discount, so a nice chance to upgrade.

Sadly,I don't live in the area and my house was built in the 1930s with solid walls, so I doubt I'll ever qualify for such a trial.
 

spinaltap

Distinguished Member
After my initial home survey, followed by a visit from the system designer, and then electrician, the installer team visited my home.

All my standard 15mm pipes would have to be replaced with a combination of 22mm and 28mm pipes. Micro-bore pipes are a complete no go (in our wet rooms). So, all the upstairs floorboards require lifting - and all box cowling between ground and first floor opened-up/enlarged to accommodate new pipe work (otherwise they would have to be surface mounted).

In addition to housing a new hot water cylinder in our airing cupboard, an additional 40 litre water buffer tank would have to be located close by. Our roof is shallow, so there’s no room there for the buffer tank. I suggested fitting a horizontal buffer tank instead, but they weren’t willing to do so.

This means that we are unable to take part in the trial. Like me, I doubt that many others will have the necessary space to accommodate all the necessary components required for installing an ASHP.
 

Field Marshall Eccles

Active Member
After my initial home survey, followed by a visit from the system designer, and then electrician, the installer team visited my home.

All my standard 15mm pipes would have to be replaced with a combination of 22mm and 28mm pipes. Micro-bore pipes are a complete no go (in our wet rooms). So, all the upstairs floorboards require lifting - and all box cowling between ground and first floor opened-up/enlarged to accommodate new pipe work (otherwise they would have to be surface mounted).

In addition to housing a new hot water cylinder in our airing cupboard, an additional 40 litre water buffer tank would have to be located close by. Our roof is shallow, so there’s no room there for the buffer tank. I suggested fitting a horizontal buffer tank instead, but they weren’t willing to do so.

This means that we are unable to take part in the trial. Like me, I doubt that many others will have the necessary space to accommodate all the necessary components required for installing an ASHP.
That went well then.
 

spinaltap

Distinguished Member
Having read the literature on Mitsubishi EcoDan Hybrid ASHP, and Daikin Hybrid ASHP, neither company require home owners to replace their existing pipework nor radiators.

With the EcoDan Hybrid ASHP, Combi Boiler owners don’t require a hot water cylinder, either.

If you opt for the stand-alone Daikin High Temperature ASHP, with water flow rates of 70 degrees, you don’t need to replace your existing pipework nor radiators. In this situation, their Hydrobox, plus hot water cylinder are the requisite additional components.
 

edbond

Novice Member
Just had the install by British Gas done at mine. 1960s some, 225m2. Guys did a really good job. You need about 2m of free wall space in 1 location, or an open mind / creativity to house it around the home. Discount is massive (70%)
 

edbond

Novice Member
Do you have external wall insulation?
Did they give you an idea of the savings?
What happens after 2 years?
No, not yet. It's a 60s build which had cavity wall insulation blown in the 80s.

No, nothing on savings or costs other than it could cost slightly more in elec than equiv of gas. I have solar panels so hoping to offset that difference and be the same as gas or cheaper. CoP is well over 4 at the moment....but it is nice out!

Nothing happens after 2 years.
 

edbond

Novice Member
You can see my comments - I can't honestly pass judgement until i have had a cold spell. Some of what he says is correct, some of what he says is wrong....
 

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