14 replies to this topic

[FLD]

I need a new boiler so I'm looking at sir source heat pump systems. Anyone on anything like this? Looking into a heat pump and solar panels to run it. Just wondering how good they are.

[Madmitch]

I'm somewhat out of date on this but from memory - look at the rating plate and you will see two numbers quoted in watts, absorption and output.  Absorption is what the pump consumes from it's mains connection and output is what it will deliver in heat.  The ratio used to be around 1:3 but I believe now it is nearer to 1:4 so, 1000w electricity consumed gives heat output around 4000w.  Another point to bear in mind is the noise these things make / made, maybe they are quieter now but you will have some sort of constant background noise, probably audible even though it will be outside the house.  Last point is the solar panels which don't deliver when it is dark which is when it is cold, also it would need to be a big array to deliver the sort of power required and then it would need batteries and an inverter, much simpler to have grid linked solar panels and a mains powered heat pump.  Hope that helps a bit.  

[Jetpilot]

I need a new boiler so I'm looking at sir source heat pump systems. Anyone on anything like this? Looking into a heat pump and solar panels to run it. Just wondering how good they are.

 

A very brief answer, for the amount of money it will cost you, it will take years and years for you to actually be back in the red for the outlay and by then, the tech will be out of date, not taking into account any repair bills etc.

[KurtVerbose]

My house came with a ground source heat pump. It was almost 20 years old and broke down a month or two after buying the house (I knew it would need replacing).

 

They're a great technology, but the installation has to be right. Mine was connected to radiators. A heat pump is only effective over a narrow temperature range. Radiators have a low surface area so require +60°C, which is beyond the efficiency of a heat pump. I installed underfloor heating and bought a new heat pump - which wasn't cheap, but the house is now warm and much cheaper to run than electric or oil - which were the alternatives. The heat pump rarely heats the water beyond 30°C, and never beyond 40°C. It's also connected to the hot water tank, so it uses the heat pump to get warm water, then the electric hot water system heats it further to 60°C.

 

They do make noise. It's normally not continuous because the hot water goes to a buffer tank. I wouldn't want it in my lounge though - I have a machine room for it. The old one was very noisy, and also in the house. Used to wake me up when it came on in the night with a bang. It was also enormous. So they're getting smaller and quieter.

 

Ground source heat pumps are more efficient than air heat pumps, but there's not much difference until the air temp really drops - which it does here in Switzerland, but rarely does in the UK.

 

In the UK you have gas, which isn't available where I live. As JetPilot has pointed out, it may be a very long payback time.

Edited by KurtVerbose, 13 February 2018 - 11:58 AM.

[jim61]

Great idea to go green , was thinking about solar water heating as a secondary to our gas boiler, even installing yourself as has bern said it just doesn't stack up economically.

[Madmitch]

We have had solar water heating panels since 2005 and there is no doubt that they make a big difference although we have much more sun here than in the UK.  For about four months of the year we do not run the immersion and for about four months in the winter they contribute little.  As above it is all about having enough time to amortise the cost.  

[siztenboots]

We have had solar water heating panels since 2005 and there is no doubt that they make a big difference although we have much more sun here than in the UK.  For about four months of the year we do not run the immersion and for about four months in the winter they contribute little.  As above it is all about having enough time to amortise the cost.  

 

if you have a large pool to heat , then it makes a lot more sense

[FLD]

The government have grants that pay out over 7 years for people having them fitted. It doesn't cover the cost but nearly does. You can get finance over 7 years which is timed in with the grant payments which is why I'm considering it. The radiators worry me if they'll put out enough heat.

[hairy]

My mate has a system installed - as Kurt points out, they will only heat up to 30C or so, consequently you need relatively large radiators to heat the house.

[KurtVerbose]

Here was my old heat pump and buffer tank. When I removed the buffer tank it looked like the space shuttle external tank. Only just went through the door.

 

 

Here's the new one. Heat pump on the left (with the VX soft top on it), buffer tank in the middle, hot water tank on the right.

 

 

It's way below freezing outside, nice and warm inside, but this is the temperature of the heating system at the moment.

 

[FLD]

This is great stuff! Thanks.

[KurtVerbose]

Of course, this helps.

 

[nicollow]

Of course, this helps.

 

 

A foot helps how? 
 

[Jetpilot]

I have just had a chat with my eco mate and he is off this week to do a course on a new air source heat pump that also has a pv panel built in, way more efficient than normal ones and the next level apparently, may be worth checking them out, will try and get a link.

[FLD]