How Boz

[TPK]

Following on from Nickds1, I understood that most installations needed 3 phase electricity, so apart from the heat pump etc install you also need to consider the cost of changing your electricity supply.

 

[Jameshow]

Also is the infrastructure going to cope to the extra power Requirements????

End connection, substation and power station.

Cheers James

 

[nickds1]

Following on from Nickds1, I understood that most installations needed 3 phase electricity, so apart from the heat pump etc install you also need to consider the cost of changing your electricity supply.

Not as I understand it. We only use 3ph as it was available due the the core of the original building being an Oast house which used 3ph fans, thus we already had 3ph on site.

1ph is perfectly normal - The power consumption of a heat pump is quite low as it's essentially just a couple of circulation pumps (one for the external loop, one internal) and a compressor. Not much more than a large fridge.

The only time significant power is used is during the weekly sterilisation cycle when an electrical jacket (essentially a kettle element) is used to bring the hot water temperature up to a level that kills bacteria in the system - this feature can easily be handled by a typical 1ph supply.

 

[Austin Branson]

Hello folks, I’m just going to add my thruppence worth. We live in a 300 year old ex-farmhouse in Normandy. Weather is very similar to southern Britain. House was re-furbished some 40 odd years ago, some new (barely insulated) walls, the old barn-end converted to habitable space, and I added a well insulated porch some eight years ago. Total area about 160 square metres.
We installed a solid-fuel Rayburn, plus radiators when we moved in 2007, and a couple of years ago I finally gave up on cutting, splitting, stacking and carrying about 12 tons of firewood every year to feed the Rayburn.
We replaced it with a Hitachi integrated ASHP. Ridiculously expensive, even with grants of about £5,000, our bill was still more than £10,000.
It works. Our annual electricity bill was about £900, and firewood was over £1,000. We have no gas. Electricity bill now is about £1,450.
Though when it was installed we had a single phase, 60 amp supply (maximum domestic supply in France), the purchase of an induction range cooker forced us to upgrade to a 240 amp, 3 phase supply.

Heating is programmed on (20 degrees) for 10:00am, and goes to night setting at 10:00pm 16 degrees. In reality the heating generally starts up at about 8:00 am in really cold weather (it’s an intelligent system), and the dining room (where the thermostat is usually) has never got down to 16 degrees. So no heating overnight.
We are pretty happy with it.
Down sides? Other than the horrendous price for purchase/installation, the only real problem is the space taken by the integrated unit (it includes a 200 litre hot water tank).

 

[doctor Bob]

Just a point my GSHP is located in an outbuilding along with 3 very large tanks and a ton of plumbing, in a house it would take up at least an area 4ft x 12ft, and it hums, hence it's located in an out building. The hot water is on a continuous loop to the house via a 40m super insulated pipe, I think the pipe was £50/m.

 

[clogs]

why is the water in the GSHP not kept seperate...or is it....?
the hot water tank has just the normal heating loop......
surley something like anti freeze added to the system would stop bact growing.....
as I see it, the water in the heating system is just a continu loop with some kind of tank for keeping the level correct....
the pumps for this system are only for keeping the water moving....
why the compressor.....?
I have a solar water heating system that works very well.....it has anti freeze in it as standard.....apart from freezing which normally dosen\t happen here the A/Freeze just stops corrosion....ps the hot water tank and the heating loop is St/Steel.....
just an interested party....no axe to grind.....

 

[gcusick]

why is the water in the GSHP not kept seperate...or is it....?
the hot water tank has just the normal heating loop......
surley something like anti freeze added to the system would stop bact growing.....
as I see it, the water in the heating system is just a continu loop with some kind of tank for keeping the level correct....
the pumps for this system are only for keeping the water moving....
why the compressor.....?
I have a solar water heating system that works very well.....it has anti freeze in it as standard.....apart from freezing which normally dosen\t happen here the A/Freeze just stops corrosion....ps the hot water tank and the heating loop is St/Steel.....
just an interested party....no axe to grind.....

The GSHP hot water system is very much as you suggest - the heat pump circulates heated water through a heat-exchanger in the domestic hot water tank; this circuit is sealed. Domestic hot water is supplied from the tank; the legionella cycle raises the temperature of the water in the tank to >60C for an hour, to kill bugs in it. Our house also has a ‘pumped return’ hot water system that reduces the length of dead pipe limbs, and means that hot water arrives pretty well instantly throughout the house - important as some of the pipe runs from the DHW tank are approaching 20m. Also reduces water consumption.

The compressor in the heat pump is intrinsic to its operation. It compresses a refrigerant that absorbs heat from the ground-loop fluid, and releases it to the heating and hot-water systems, just like a refrigerator.

 

[doctor Bob]

why is the water in the GSHP not kept seperate...or is it....?
the hot water tank has just the normal heating loop......
surley something like anti freeze added to the system would stop bact growing.....
as I see it, the water in the heating system is just a continu loop with some kind of tank for keeping the level correct....
the pumps for this system are only for keeping the water moving....
why the compressor.....?
I have a solar water heating system that works very well.....it has anti freeze in it as standard.....apart from freezing which normally dosen\t happen here the A/Freeze just stops corrosion....ps the hot water tank and the heating loop is St/Steel.....
just an interested party....no axe to grind.....

Hi,
So the loops underground are full of a brine like liquid, mine is green in colour and this loop is totally separate from hot water and heating. The brine goes out at about 4deg and comes back at 7degs, the GSHP uses the compressor to extract heat and heats the hot water system and the buffer tanl for the underfloor heating.