ground source project so far

[Servotech]

Hi Mikey, sorry to hear about the person you know problems surrounding the freezing of their unit.
Lucky I was passing because I'm one of the real experts on here who knows all about GS heating.

What you and your coleague need to do is to install another cylinder(heat bank) which will store previously heated water and keep it up to temp via a thermostatic three way valve.
So when the temperature next plumets to below zero the heat pump then takes the heat from the storage cylinder(heat bank) inside the property and then deposits it back into the ground thus preventing it freezing.
Don't worry about losing the heat because you are merely putting it back into the ground only for it to be re-collected at a later date once the temperature lifts to above zero again.
Look upon it as a heat bank (which is what it is).
GS is a very simple method of heating but you really need to know what you are doing with it (like I do), then once you do it's win win win all the way!
Good luck with your project and I hope this information is a big help to you.
Servotech
(Technical help at your service)

 

[Agile]

"""A Coefficient of Performance (COP) of around 50 can be achieved using AWADUKT Thermo which, compared with a typical COP of between 3-4 for a ground-source heat pump, makes it a very efficient source of renewable energy. It has attracted interest from both Germany’s Passive House Institute and the UK’s Carbon Trust.

REHAU’s RAUGEO ground-source range extracts energy from the ground via pipework used in conjunction with a heat-pump. Ground-source probes are manufactured from cross-linked polyethylene (PE-Xa) and are sunk in boreholes at depths of up to 100m, whereas ground-source collectors are buried typically at 1.5m deep over a large area of around 200m².Ground-source systems can typically supply up to 75% of a building’s heating requirements. It is ideally combined with a low-flow temperature underfloor heating system to provide optimum efficiency. To reach the temperatures required for radiators, the heat pump would require more energy and hence, the whole system would be much less efficient."""

How do they claim a COP of 50 ???

Digging a 100m deep hole would be a chalenge for the OP's digger machine!

The OP seems to have 12 m² rather than the suggested 200 m² suggested above!

All this free advice he has used to desing and self-install looks set to meet just 5% of his heat needs! And even thats only going to be until the ground is frozen!

It would make me smile if one of the "advisers" attending free intentionally gave him incorrect information because he realised that he was a free-loading DIYer!

Tony

 

[simond]

Lucky I was passing because I'm one of the real experts on here who knows all about GS heating

They're coming along like buses at the moment, pal. My local ASDA has sold out of Superman suits.

 

[yourmoneyoryourwife]

Servotit you haven't got a clue bet youve never seen a heat pump let alone installed one

 

[Agile]

Its getting even better!

The COP has just gone up from 50 to 100 ! That means for just 100watts ( the power of an old light bulb! ) you can get the 10 kW of heat needed for your three bed semi !

To quote AWADUKT:-

Ground-air Heat Exchanger

GRAND DESIGNS FINALIST - BEST INNOVATIVE PRODUCT 2009

Our AWADUKT Thermo ground – air heat exchanger is a unique product which uses the natural temperature of the earth at 1.5m below ground to pre-cool or pre-warm fresh air as it is drawn into a building through a network of underground polymer pipes.

Fast and easy to install, AWADUKT Thermo offers a class leading Coefficient of Performance (COP) of up to 100 which means that for every 1KW of energy consumed, up to 100KW is generated.

Makes you wonder why anybody bothers to burn gas any more!

For that one you only need 40m of 200mm diameter pipe buried 1.5m to 2.0m deep. The sewer in the main road is about 200mm so perhaps I could tap into that? Dont know how good it would be though if I froze the sewer.

With COPs of 50 and 100 available why is anyone selling heat pumps with the more usual COPs of 2-3 ( under ideal conditions )?

Tony

 

[htgeng]

It would make me smile if one of the "advisers" attending free intentionally gave him incorrect information because he realised that he was a free-loading DIYer!
Tony

*cough* not that any of us have ever done that.

 

[doitall]

A COP of 5 was quite realistic in my days in the field Tony, so perhaps they are even better now.

The main problem we had was 3phrase supplies, but with inverter technology, that has been overcome.

 

[Servotech]

Servotit you haven't got a clue bet youve never seen a heat pump let alone installed one

I've kept it simple so that dummies like you will be able to understand.
Read my post and learn.

 

[Onetap]

Its getting even better!

The COP has just gone up from 50 to 100 ! That means for just 100watts ( the power of an old light bulb! ) you can get the 10 kW of heat needed for your three bed semi !

I think you may be confusing this with the CoP used in relation to chillers, ASHPs or GSHPs. This is just a simple ratio of the energy input to the metered energy expended.

This system is just a series of large diameter pipes buried in the ground and works with large ventilation plants. The metered energy input is the additional fan energy needed to draw the air through the large pipes. The energy input is the heat transfer from the ground to the air.

It works; I attended one of those CPD seminars (eat free sandwiches whilst sales representative drones on about summat until eyes glaze over) about a similar system.There's a huge amount of digging involved in installation, so the disadvantage is the big capital cost.

There's no refrigeration compressor involved; it has nothing to do with GSHPs.

 

[Agile]

Even with big pipes and even if they were 100m down I dont see how a 100w fan could even move 10kW of heat even if that heat was at 15°C..

In any case what use is cool air at 15°C for any heating for occupation without a heat pump to increase the temperature?

In return for free sandwiches I try to stay awake. Gas Safe only gave us coffee!

Tony

 

[yourmoneyoryourwife]

servotit the idea of a gshp is to recover heat from the ground not to cool the water that youve already paid to heat by pumping through the ground loop.
You can preheat the ground using solar and a separate ground loop i think youre getting confused and its obvious youv'e never touched a heat pump before. By the way whats a collage!

 

[manortim]

ahhh....another fool and his money being parted!

love it!

 

[mysteryman]

A 'collage' may be something that 'plumets'.

I find it hard to trust a self-proclaimed expert who is unable to spell.

 

[Onetap]

Even with big pipes and even if they were 100m down I dont see how a 100w fan could even move 10kW of heat even if that heat was at 15°C..

In any case what use is cool air at 15°C for any heating for occupation without a heat pump to increase the temperature?

It's not a separate fan. The energy is the additional energy required to draw the intake air through the network of buried ducts. There would probably be times when you didn't want to pre-heat or pre-cool the air. Most AHUs have soft-start inverter drives now, rather than star-delta starters; the belts last longer too. I don't reacll a CoP being quoted for these installations, but it would be above 10.

Air at 15 degC would probably need additional heating, but if it were 0 degC outside, you've obviously saved some energy on the heating costs.

 

[Onetap]

one of my main concerns is freezing the ground as the person i purchased the heat pump from had just that happen to them thus they was forced to sell the pump, there ground collectors were in the front garden and during the cold spell at the beginning of the year they returned from holiday to find the water board diging the road up outside the front of there house, the pump had not only froze there garden and drive but also permutated out into the street and froze the main water pipes to the rest of the road!,

Interesting. They went on holiday, left the GSHP running and froze the water mains!

I wonder whether his PLI covered him for split water mains. Was it a DIY installation?
Are you covered for frost heave claims if your foundations, or a neighbours, are affected? Could be expensive.