Author Topic: Ground source heat pump - advice needed please (Read 18964 times)

egbert · « **Reply #15 on:** January 31, 2011, 07:51:58 pm »

Oh - to add. The insulation was being done anyway, as was changing the radiators. So, it runs through standard radiators with TRVs - the gravity fed hot water cylinder was removed and there was piping and electrics put into the garage. They made no mess in the house at all.

Oh - and we have 4 solar panels on the roof which provide all the summer hot water, so no need for the pump to do it.

luissousa · « **Reply #16 on:** February 04, 2012, 06:16:30 am »

The European Ground Source Heat Pump Association (EGSHPA) website is a business tool dedicated to helping professionals and delivering up to date news and training to further their knowledge and business connections.This website site is designed to make everyone feel part of the community in a totally proactive manner. The European Ground Source Heat Pump Association (EGSHPA) was founded as a non-profit making association and built with the aim of communicating to the industry and consumers the benefits of a new form of renewable energy.
EGSHPA is the ideal bridging point between the latest green energy technologies and the people who benefit from these developments. GSHP is benefial for the enviroment as well as its installation help in saving money, save energy, operating cost.
I would suggest you to install Ground source heat pump as they are electrically
powered systems that tap the stored energy of the greatest solar collector
in existence: the earth.
It benefit the enviroment as well as its installation help in saving money,
save energy, operating cost.

For detail visit:
http://www.egshpa.com/

chrismahon · « **Reply #17 on:** February 04, 2012, 06:28:21 pm »

I've recently been on a course all about this. I'll start by saying the most enviromentally friendly heating is wood.

Heat pumps are only cheaper than basic electric heating because they produce more heat than the energy you put into the pump. This ratio is the CoP, coefficient of performance. At best 1:4 at worst 1:1.5.

What affects the CoP is the heat source extraction efficiency and the output temperature, plus obviously system running efficiency.

With ground source there is a trend to run radiators at 50 degrees instead of underfloor heating at 30 degrees. The net result is to reduce the CoP from between 1:4 to 1:3 down to 1:2 ,at which point the cost of installation, maintainence and repair (including replacement boreholes) renders the system little better, if at all, than simple electric heating.

Air source heat pumps ice up in the humidity of the UK. They then reverse, taking heat back out of the building to clear the ice. This can happen up to 3 times an hour. So the pump needs to be sized 30% bigger than calculated and sited well away from footpaths or driveways.

You would be amazed at the saleman claims made before the course started. Then the experts and installers started to speak! "And it all went quiet over there".

janeislay · « **Reply #18 on:** March 21, 2012, 04:56:15 pm »

We've had an air exchange system installed. Costs about £3500 to install and about £280 a year to run all the heating in the house except water. It's brilliant and works in both old and new houses when temperatures go as low as minus 20 degrees C.

This is their website: www.eheatgroup.com

Norfolk Newby · « **Reply #19 on:** March 23, 2012, 02:52:41 pm »

The heat pump idea goes back quite a long way. When the Royal Festival Hall was built in the early 1950's, a redundant merlin engine from a Spitfire or Lancaster bomber was installed to provide the heating. It used its supercharger to compress gas which then provided heat all around the building. The gas then expanded cooling it. Water from the Thames then reheated the gas. It achieve a COP of 4 which was pretty good for the time and the technology used.

There are a couple of lessons here for anyone considering a heat pump system. The merlin engine required a lot of maintenance and the idea was dropped after a few years. Modern heat pumps are very similar to a big fridge compressor. They should run happily for 10 years but will need replacing and are not cheap.

The source of heat is important. Soil is probably better than air but if you have any local heat source like a stream, large pond or waste heat from a factory or brewery, it will help the COP a lot. A figure of 6 or more is then possible.

Also, you could use a small engine to drive the compressor. Something like a small diesel engine from a tractor. You would only need a few horsepower continuously as 1hp=0.75Kw. Multiply this by the COP to get the heat output. This means heating oil could be used as fuel rather than electricity. Waste heat from the engine can then be collected to heat the house as well as the heat from the compressor so that the exhaust gas and the engine cooling system all contribute.

The downside of this idea is the noise and maintenance costs. But it is worth considering.

Dizzycow · « **Reply #20 on:** March 23, 2012, 03:18:50 pm »

We have it, we love it. We were advised two things which we did and would advise anyone to do the same.... Don't mix radiators with underfloor heating, it's less effective apparently. The second thing is to over spec your tanks, again it makes the system more efficient. We don't have a back up system, at the moment (we have HelpXers staying) there are 7 of us living here and we never run out of hot water.

cloddopper · « **Reply #21 on:** November 14, 2013, 09:44:15 pm »

I've found this topic thoroughly interesting especially the heat exchange air pumps from eheatgroup.com .
We are spending around two & 1/2 tanks worth of oil for heating & hot water a year (in excess of £2.5 k perhaps ) despite having a complete new latest bees knees heating system and full wall & roof thermal insulation. . Seeing as we have a Wi-Fi room stat we can drop that to zero and still have plenty of hot water from the balanced flue oil combi boiler . It sounds like these heat systems could be good for us

Can any one tell me ........ does the warm air in help dry out damp musty places. I ask because :-

We got flooded out 4 yrs. ago due to " Mr Nearly" who we purchased the property from playing at being plumber , builder & electrician when the hidden central heating pipes leaked and flooded the whole bungalow floor slab . It took over a year to try and get it dried out and repaired whilst we lived elsewhere .

This last 18 months we've noticed we get a musty smell if the bedrooms doors are closed. We don't usually heat them unless it's a heavy frost forecast though we do have trickle vents in all windows for which the smallest air flap is always open to keep an air flow going as well as we opening most windows for fifteen minutes to half an hour or so each day to sweeten the home up.

perdita_fysh · « **Reply #22 on:** August 03, 2014, 08:32:48 am »

Thanks for all the useful advice here, we are looking into replacing the oil system here in our very old house with a GSHP system. We've had one quote so far but it was a commercial one to include heating the chicken shed. If we were chicken farming it would represent a great saving, but as we're not it would be far too expensive so I'll be getting some domestic quotes shortly.

The guy we saw said that several deep holes would be cheaper to install than the equivalent shallow hole, which surprised me but perhaps that was because of the scale proposed. But he never mentioned streams or ponds so I was really interested in the comments on here about that. We have 3 streams and a pond on our land, although only one stream is near the house. How do you install a GSHP to make use of the advantage of a stream?

Dreich Pete · « **Reply #23 on:** August 03, 2014, 08:49:23 am »

I can't offer advice as such because we bought the house with GSHP already installed, and I haven't calculated the bills yet - there's a very odd situation with the eclectic it's company - but our estimated monthly payment is not much more than our total gas & electric payments at our old house, and now we have constants hot water (ok, a big storage tank) and underfloor heating around the whole ground floor and two radiators upstairs.

It seems to me that GSHPs aren't fantastically cheap to run but you do get a cosier house - assuming it's well insulated as mentioned here before - and there are options to make it more efficient and even off-grid safe.

We've been told by a couple of professionals that we should consider a solar hot water panel or two that would be fitted in front of the heating system to pre-warm the water and therefore reducing the energy required to heat the water. Obviously this only works during the day, and better on sunny days than dull ones, but it works out a much cheaper and more efficient option than solar PV. We'll probably get solar PV too, but at the same time as the solar hot water to save on installation costs.

One downside to GSHP powered undefloor heating is that if you don't have room thermostats installed you won't be able to control the house temperature very quickly - our system takes at least 12 hours to adjust because of course it is dependent on the loop and heating process. We tend to leave it quite low all the time and it balances out. During the summer I've even turned it so low that the floors are almost cold, and in the winter we crank it up but support it with the log burner in the living room.

After a year with this system I don't think I would pay my own money to instal it, but as it was included in the house when we bought it I'm happy to have it.

happyharry · « **Reply #24 on:** March 11, 2015, 01:49:12 pm »

We installed a GSHP about 18 months ago and have monitored performance and costs.
Our house dates back to 16thC. We did upgrade insulation where possible but that was limited because of clay lump walls. All radiators had to be replaced, and we also opted to put in some under floor heating whilst carrying out other works in some of the ground floor areas.
The first full year of operation cost us an additional £490 in electricity compared to our electricity consumption the previous year. Consumption over the past last six months is very much in line with the first six months so I would expect our 2nd full year additional electricity cost to be in-line with year 1.

Previously, we were using an oil fired boiler and spending around £2000pa on heating oil.

The past two winters have been relatively mild so accurate comparisons with earlier years are almost difficult to achieve.
A further big plus is that the house is much warmer. The old oil boiler used to be on about 8 hours a day so we had significant parts of the day without heating, whereas the GSHP system runs 24/7 and the house is cosy all of the time

So: a warmer house, a 4:1 energy efficiency resulting in a 75% reduction in energy spending

What did it cost ?: around £30,000, excluding the under floor heating which was part of a larger project

What about the RHI payments ?: We get a quarterly RHI payment which, over the 7 year period that it will be paid, will amount to around £30,000. So we get our money back (without interest) and will also save around £1500 a year on oil

Conclusion: It's a big outlay. £30K would buy a lot of oil. Without the RHI it would never stack up. It works for us, and we are very happy with the performance