Air Source Heat Pumps

[Deleted User]

What you want is a business that has a solid background in heating systems that is also MCS registered with many installs under their belt. It's amazing how many MCS registered installers there are that have never installed one for real!

And trust me there was only one company in my area that came accross as experts in renewables as well as LPG, Oil, Gas etc Most were complete muppets - I knew more fom reading the Ecodan installer guides than they did!

I don't think the situation has changed much in the last couple of years either no thanks to the RHI fiasco... I've seen a couple of other installs in my area and my first thoughts were, Oh dear...!

Leading on from that it does not surprise me that some COPs are carp.

PS on sunny winter days the PV can reduce the ASHP running cost ~50% Great for days when the wife does not work Cheap heat ~2p kWh + FITS, Export and watered down RHI soon, Nuts!.

Air_Source_Heat_Pump_Man

Jeepjunkie makes the very important point that the quality of the installation is critical, in any system. It is made more so in heat pumps as they do not like being oversized, as hey have compressors and thus they do not have the extra capacity of oil for instance.

There is though, no reason that a heat pump cannot heat any building, it just needs to be big enough and that is usually limited by electricity supplies and or budgets. So yes, insulation insulation insulation, but that is for any heating system.

PV and ASHP are a great match for a good example there is a property that is off every grid - water, gas and electric if you search for RURAL ECO HOME OFF GRID WITH AIR SOURCE HEAT PUMP
ASHP are becoming more and more widespread and are really entering the man stream now.

Air_Source_Heat_Pump_Man

You could try Natural Gas Services in Hull - nearest I know of

Cardew

Air_Source_Heat_Pump_Man wrote: »

Jeepjunkie makes the very important point that the quality of the installation is critical, in any system. It is made more so in heat pumps as they do not like being oversized, as hey have compressors and thus they do not have the extra capacity of oil for instance.

There is though, no reason that a heat pump cannot heat any building, it just needs to be big enough and that is usually limited by electricity supplies and or budgets. So yes, insulation insulation insulation, but that is for any heating system.

PV and ASHP are a great match for a good example there is a property that is off every grid - water, gas and electric if you search for RURAL ECO HOME OFF GRID WITH AIR SOURCE HEAT PUMP
ASHP are becoming more and more widespread and are really entering the man stream now.

25,000 people in the UK do not have mains electricity, according to Resource magazine. - about 0.005%. So we are not talking 'main stream' here!

Googling as you suggest gives this link!

http://www.globalenergysystems.co.uk/residential/rural-eco-home-off-grid-with-air-source-heat-pump

It states the 'annualised cost estimate is £0' whatever that means!

It also states:

'By combining a Stirling Eco Air Boiler with 20 solar PV panels the property is able to generate enough electricity to off set the heating on most days of the year'

Now given that solar PV doesn't generate when dark and often virtually nothing during the day. Presumably 'to generate enough electricity to off set the heating on most days of the year' you must rely on storing the electricity in batteries??

I haven't looked up the weather for the Lancashire moorland but the couple of times I have been to the Forest of Bowland it was misty most of the day.

The data sheet of the ASHP states it requires an input of 3.2kW to 3.6kW; and as we know an ASHP will need to run 24/7 when cold. So it could need as much as 80kWh a day.

There is a thread running on the 'green' board and many people are generating next to nothing on many days in winter(and obviously nothing after 4pm/5pm.)

What capacity are the batteries?

A 20 panel PV system is 5kWp?? in the North-West of UK would generate around 4,000kWh pa?? - most of this in summer. During the season when heating is required it would generate less than 1,500kWh??

Presumably this is a firm you are connected with?? If so can you please explain the theory behind the system - I am not trying to be smart - just interested.

matelodave

I've got a heat pump and I've explored whether Solar PV or even E7 would be worthwhile and I've come to the conclusion that neither of them would match the power requirements of a heat pump.

It's consumption is generally less when the sun shines as you get the benefit of solar gain on the house and the air temperature is higher than when dark, wet and gloomy. The unit works hardest when it's cold and dark, especially in the evenings and early mornings, so even E7 might only give a minor benefit of heating water during the off-peak time however that would be offset by the extra cost of running the system on the higher priced tariff - potentially E10 might work but it would be marginal.


You need to do some complicated sums to decide whether a heatpump & solar PV would be cost effective and what sort of payback you'd get.
For me the heatpump was an easy decision - I needed a heating system anyway so I could justify the additional cost as it has a payback of 5 years or so.

Solar PV is much harder, as it's capital outlay with a payback of 8-9 years. I can think of a lot more to do with £7-10k than screw it on the roof and hope the government keeps it's promises

[Deleted User]

Cardew wrote: »

The data sheet of the ASHP states it requires an input of 3.2kW to 3.6kW; and as we know an ASHP will need to run 24/7 when cold. So it could need as much as 80kWh a day.

80kWh :eek: What size of house would that be for?

Previously I've described my 100+ year large detatched home and even in the thick of winter with temps of minus double figures we knock on 50kWh for everything.

So I reckon the average Wimpy box might be in the 30s?

Cheers

matelodave

We don't measure our consumption daily but our very highest consumption for a month was last January when we used 1499kw/h in 31 days = 48kw/day average.
That's all the energy that we use for heating, hotwater, lighting, cooking, washing, tumble drying, dishwasher, vacuum, TV, computers etc. I reckon at worst the heatpump takes up to 30kw a day, usually much less.
We are home all day every day so we keep the place cosy all day, reducing the temperature in the bedrooms & bathroom during the day. We have temperature set back by 3 degrees on the stats and the unit has a -5 degree set back overnight as well which stops the place getting stone cold overnight as it will take a long time to recover.
I discovered that during the first winter we had it. I had set all the stats to frost protection whilst we were away for several weeks in December and it took a couple of days for the house to reheat.

Cardew

jeepjunkie wrote: »

80kWh :eek: What size of house would that be for?

Previously I've described my 100+ year large detatched home and even in the thick of winter with temps of minus double figures we knock on 50kWh for everything.

So I reckon the average Wimpy box might be in the 30s?

Cheers

You need to read post#1553. This is the link to the house that is not on the electricity grid and in a very cold part of UK - Lancashire moorlands:

http://www.globalenergysystems.co.uk/residential/rural-eco-home-off-grid-with-air-source-heat-pump

I appreciate that 80kWh is the theoretical maximum, but it is the principle I cannot understand - PV panels providing electricity to run an ASHP in winter and at night!!

zeupater

Hi All

I'd hazard a guess, albeit a logical one, that the article referenced is a little misleading in that the property is off-grid for gas, but on-grid for electricity, with the FiT income from the summer pv generation being offset against the winter running cost of the heating ..... this would partly explain the claims of the property being carbon-neutral and the fuel running cost of the system (pv+HP) to be zero if the annual generation & consumption were in balance ... however, the building must be incredibly well insulated to reach this point of equilibrium without a secondary form of heating - if you look at the picture taken from across the water, the right of the building looks to have a stainless-steel flue-pipe topped with a black cowl rising to above the roof ridge, which, to me, suggests that there's a log-burner centred on the end wall.

HTH
Z

Cardew

zeupater wrote: »

Hi All

I'd hazard a guess, albeit a logical one, that the article referenced is a little misleading in that the property is off-grid for gas, but on-grid for electricity, with the FiT income from the summer pv generation being offset against the winter running cost of the heating ..... this would partly explain the claims of the property being carbon-neutral and the fuel running cost of the system (pv+HP) to be zero if the annual generation & consumption were in balance ... however, the building must be incredibly well insulated to reach this point of equilibrium without a secondary form of heating - if you look at the picture taken from across the water, the right of the building looks to have a stainless-steel flue-pipe topped with a black cowl rising to above the roof ridge, which, to me, suggests that there's a log-burner centred on the end wall.

HTH
Z

However in post #1553 'air source heat pump man' posted:

PV and ASHP are a great match for a good example there is a property that is off every grid - water, gas and electric if you search for RURAL ECO HOME OFF GRID WITH AIR SOURCE HEAT PUMP

The brochure states 'When converting this off grid barn' .

The term 'off-grid' is surely only used to mean off the electricity grid. you would hardly expect a house high up on the remote Moorland to have mains gas.