Ground Source Heat Pumps

lovesgshp

If you go for the gshp, you will not need a hybrid system, as it works down to around -35C. Yes, additional heat will kick in if needed, but it is not a normal thing if the pump is sized correctly. Here it is about 46 hours over 10 years.

albyota

Lovesgshp, what is the highest capacity can GSHP be on single phase?
I thought 14 /16kW was the highest from most manufacturers like Danfoss Dimplex Stiebel Eltron Nibe etc.

Edit. OP must have 3 phase as he has 10 kWp PV system.

lovesgshp

albyota wrote: »

Lovesgshp, what is the highest capacity can GSHP be on single phase?
I thought 14 /16kW was the highest from most manufacturers like Danfoss Dimplex Stiebel Eltron Nibe etc.

It varies between manufacturers. IVT go to 11Kw, then to 3 phase over. Single phase normally needs a soft starter, whereas 3 phase does not

edwh

I'm single phase currently - we got lucky on the PV.

captainhindsight_2

edwh wrote: »

Lovegshp - doesn't it kill you on the operating costs if you're using the immersion heater?

Albyota, what's the heat metering package? I've not considered a hybrid system but that would mean replacing the oil tank too, so the cost might be quite high.

I think you question about the heat meter got mist....

The domestec rhi is calculated and paid in two ways.

Option 1 the renewable technology meets 100% of the properties heat demand and there is no fossil fuel back upand the rhi payments are calculated using the figure shown on the EPC.

Option 2, the renewable technology does not meet the heat demand of the house or it does and a fossil fuel back up is left installed. In this situation you must have a heat meter installed to measure the amount of renewable heat being generated/used and you will receive the rhi based on this figure but capped at the figure shown on the epc .
The installer should know this as it is very basic information about the incentives around the technology so I would question how much they know about renewables and the industry if they are going to be any good.

Have you chosen a heat pump yet, and if you don't have three phase you may have to cascade multiple smaller single phase heat pumps to meet you heat demand.

captainhindsight_2

albyota wrote: »

Lovesgshp, what is the highest capacity can GSHP be on single phase?
I thought 14 /16kW was the highest from most manufacturers like Danfoss Dimplex Stiebel Eltron Nibe etc.

Edit. OP must have 3 phase as he has 10 kWp PV system.

I would stay away from those manufactures !

You need to stick with vaillant as they are the only manufacturer to offer good back up and support to the consumer and the installers.

If you use a vaillant approved installer you get 7 years parts and labour warranty and this is covered by vaillant engineers not partner installers like Nibe etc rely on.so if something did go wrong under the warranty period a vaillant engineer would be with you within 24 hours with a van full of spare parts.

Any other manufacturer your installer will come diagnose the problem, order the parts and come back maybe a week later once the part has come in and it may be the wrong part etc etc etc . And your left with out heating for over a week

No other manufacture even come close to Vaillantt

Most Manufactures highest single phase capacity is 10kw

lovesgshp

Never have any problem getting parts, usually sent on a overnight express delivery.
As regards to being left without heating, unless it is a major problem, then the back-up electrical supply can be used.

Patrol

Some stats I noted while running on the backup cassette. Does a jump from 18 to 59 units mean a ground loop COP of circa 3.25?

2 Jan - 17 Jan, compressor. 32 units/day total consumption. 18.6 on GSHP.
17 Jan - 4 Feb, cassette. 72 units/day total consumption. 59.2 on GSHP.
4 Feb - 14 Feb, compressor. 31 units/day, 16.8 on GSHP.

GSHP use is approximated as not metered separately.
- % of hours on DHW at 1.7kw.
- % of hours on heating at 1.4kw.
- Hours on cassette at 6kw.

(figures for the GSHP range from 2 units/day during the hottest parts of summer to 42 units/day in December 2010 and January 2011 when external temperatures were dropping beyond -10c).

lovesgshp

Without me looking back through the posts, what model is the unit.

Patrol

I couldn't open your spreadsheet edwh.

Thermal store may be possible, have you spoken to any suppliers. Example one I see advertised is Chelmer Heating with mention of different heat sources and controls/timers. Might work well with oil too, e.g. 1 boiler and 2 supplies from the store.

GSHP ground work will depend on the land and your approach. e.g. our digger driver did the trenchwork in a morning and I did the 2 150m coils in the same day, then we backfilled after a pressure test. I'd say that is the minimum cost but have read of cases costing 5k+.

ASHP's seem popular now, one was installed near us last year but I've not seen the owner this winter to ask how it is performing.