Alternative Heating - Water Source Heat Pump

riccol1966

I have been looking at the other threads on alternative energy, firstly thanks to all contributors which have certainly helped me to separate the good from the not-so-good.

I built a 1900sq ft bungalow in 2000 and I have a typical timer based oil burner, feeding radiators. I did some calculations and my overall heating costs appear to be in the region of EUR1100 per year, made up of appx 1000 for oil costs and 100 for the electricity to the oil burner (might be a bit much but I don't have any Kw/h costs for running a standard boiler).

Firsly, in payback terms I am looking at something that is going to cut my bills in half, and am not too concerned about the initial costs. So I have 3 questions for the forum:

Q1) In terms of efficiency, not cost, am I right in saying water source heat pumps (WSHP) are the most efficient, followed by ground source (GSHP), followed by air sourced (ASHP)?

Q2) I already have a drilled well with submersible pump (appx 320ft down), 100ft from the house. Can I use this borehole for connecting to a water sourced heat pump, or do I need a separate borehole? I saw a thread earlier that suggested having a 2nd borehole done when drilling for well water, but it is not clear to me why this would be needed.

Q3) Does anyone have, or know of someone who has a well based WSHP set up, or perhaps a list of the companies that have some experience in this?

Thanks

Richard.

yop

Richard -
First off yes I would agree that in terms of efficency that the WSHP is the most efficent, followed by the GSHP then the ASHP.

I have not investigated the WSHP but I would presume that you could use this bore hole.
There was a guy on one of the geothermal threads, either here or in DIY, Nordic I think, he has experience of the WSHP, worth a talk with him

riccol1966

thanks Yop - have asked Nordic to post a reponse if he can. I have not yet come across a website with enough info on WSHP but will post details back here once the info is to hand.

Richard.

yop

have a look here

http://www.eere.energy.gov/RE/geo_heat_pumps.html

shanea

The main differences between the two are

Ground Source Heat Pumps take the heat from a closed loop of water/gycol mix (sometimes brine - rare). This anti-freeze mix circulates between the ground and the heat pump collecting heat continously. As the heat is extracted then the ground cools and the heat pump has a harder time extracting the heat.

With

Water Source Heat Pumps the well supplies a continous supply of a constant temperature water to the heat pump and will therefore maintain a higher efficiency irrespective of the time of year or ground conditions. And so is more efficient

OR IS IT?

GSHP would be circulating the water with a 300 watt circulating pump.
WSHP needs a deep well pump. The wattage required is dependant on the well depth ( can be up to 4000watts) and may exceed the running amperage of the heat pump it self, therefore being less than half the efficiency of the above.

So if the water is very high in the well, it is an option, if not don't go there.

This is by DX units have an edge on the above but then they have there disadvantages too.

Nordic

riccol1966 wrote:

thanks Yop - have asked Nordic to post a reponse if he can. I have not yet come across a website with enough info on WSHP but will post details back here once the info is to hand.

Richard.

Richard
Nordic here. Haven't been on here for quite some time. You can e-mail us at info@nordic-geothermal.com Web-site is www.nordic-geothermal.com Just popped on here to have a look busy now but e-mail me and I'll try to answer your questions.
Regards
Niall

Nordic

shanea wrote:

The main differences between the two are

Ground Source Heat Pumps take the heat from a closed loop of water/gycol mix (sometimes brine - rare). This anti-freeze mix circulates between the ground and the heat pump collecting heat continously. As the heat is extracted then the ground cools and the heat pump has a harder time extracting the heat.

With

Water Source Heat Pumps the well supplies a continous supply of a constant temperature water to the heat pump and will therefore maintain a higher efficiency irrespective of the time of year or ground conditions. And so is more efficient

OR IS IT?

GSHP would be circulating the water with a 300 watt circulating pump.
WSHP needs a deep well pump. The wattage required is dependant on the well depth ( can be up to 4000watts) and may exceed the running amperage of the heat pump it self, therefore being less than half the efficiency of the above.

So if the water is very high in the well, it is an option, if not don't go there.

This is by DX units have an edge on the above but then they have there disadvantages too.

The well water pump is only pumping the head of water from the top of the water level in the well to the surface. The water from the point at which it has levelled off due to atmospheric pressure down to the pump level is actually helping the pump pump the water. Most well would never need more than a 1.5hp pump (1250W) and these would be multi-stage and while capable of pumping up to 150l/min would only be required to pump 30l/min or so to the heat pump, so would only be using about 500W. Given that the same heat pump (picking some real data here) would be 22.6kW output with 12°C source from a well when at 35°C the electrical load is 3,050W + even 750W for a well pump would be 3.8kW input and 22.6kW output giving 5.94 COP. The same heat pump on a ground loop at -3°C source (mid-winter cold night) would be 13.9kW output when at 35°C and the electrical load is 3,691W + even only 300W for a loop pump would be 3.991kW input and 13.9kW output giving 3.48 COP. Big difference.

Nordic

BTW.. as regards heat pumps we distribute Nordic heat pumps to all of Western Europe, and don't sell UF or rads.

Some may see this as a disadvantage but in reality we can give us information on the heat pump efficiency rather than being swayed by selling you under-floor or rads.

We give free of charge training to your own plumber 1. to spread training amoungst the trade, 2. so the guy on hand when you have a leaking tap knows what it's all about, and 3 so you're not held to ransom by one company that makes you think it's rocket science and over charges for the whole "complete" job.

We don't ask you to show your house - what company is going to give the contact details of an unhappy customer? We keep your details completely confidential even to the point of losing a sale, and offer you commissions for any customers you find off your own bat.

We do:
Water-to-Water (underfloor units and radiator units)
Water-to-Air
DX-to-water
DX-to-Air

The Water source units are available for numberous water sources:
Wells
Ground loops
Streams & Rivers
Sea-water
Milking parlours

Typically a radiator syste,well source heat pump with 20/22kW output is about Eur6-7k + VAT and a well source underfloor heat pump with 20/22kW output is about Eur9k + VAT, but includes the buffer tank, floor circulation pump, stainless steel case, refrigerant gauges etc, and you can omit the floor mixing system on each manifold (about Eur600 each) and the floor circ pumps.

We are now also offering Solar panels and wind turbines to existing or new customers at low prices:
2kW turbine (complete with 8m mast, inverter,etc) for Eur2,700 + VAT
20 vacuum tube solar panels for Eur1,400 + VAT

Don't always have time to check out forums (weekends or late night generally) but e-mail me info@nordic-geothermal.com with any queries.