Geothermal and UFH Vs Oil and Rads

freddyuk · 10-01-2011 12:11AM

Oh dear, that is bad news. There are some real fans of HP's on this thread but they have not been active since the cold snap.:D

RavenII · 10-01-2011 02:19PM

Well Well Freddy its been a perfect 21.5 degrees at home right through all the snow, and why wouldn't it be? Lowest temp I saw on my weather station was -7.

Regarding the man with the broken compressor, that's unfortunate, but they are machines and machines do break from time to time whether they are boilers or heatpumps etc. ....what would irritate me is that the supplier has no spare parts and is taking a leisurely two weeks to bring the parts from Austria rather than 2/3 days normal freight time from that part of the world!

freddyuk · 10-01-2011 05:08PM

-7 !! Tropical! We were down to -11 in West Cork. I have blocked up some drafty door and window frames and my UFH has been performing well. The boiler has not been on as much as it used to be. I keep checking the tank and thinking of you. Glad to hear you are still running efficiently. I really will be installing a HP (on test) but currently installing Solar Thermal and PV as I know they work well.
You are correct, poor backup service is inexcuseable.

jimmyging · 10-01-2011 05:12PM

the poor back up is due to the fact that the company we bought the system from is gone bust .Thankfully the insulation is very good and any heat we are producing is staying put . So nobody out there has had a compressor go with a heat pump ??

kingchess · 11-01-2011 10:20PM

hi freddy .also in west cork and only noticed the bad weather when i went out side.heatpump did what heatpumps do-keep house lovely and warm,there was no need to light a fire or even use the rads upstairs.but as an old plumber told me years ago the short answer is if your house is insulated enough you could use a candle to keep house warm

xcross · 12-01-2011 12:04AM

unfortunately another request for advice on my own build but hopefully will prove useful to others in a similar setup. I've read through the previous 7 pages and spent the last month approx looking online for information and getting quotes from suppliers and installers and I am still unwise!
Geo is not an option for me as we don't have land out front or enough access to back garden for boring. Its a Cork city property.
Have been interested in both Solar and Air-to-Water HP solutions but at the moment bing a little under pressure to make a decision I am inclined to wire & pipe for both but install neither yet.
We have a 40 sqm new build area that we are putting UFH into with a 75mm screed. We also have an existing area, 5 beds, 2 living & 2 bath with 10 radiators and a condensing gas boiler.
I'm putting off the decision as I need to do more research on Solar and A2W. I would be more likely to do Solar but the house faces East and West so the panels would have to be mounted on a flat roof at rear to face South to the side of the house. The HP is a big investment so I am hesitant.
AT the moment I would like advice on tanking. I need to cater for the above future possibilities but have very limited space for HW storage or heating buffer tanks, any of these will go in our Utility downstairs next to the gas boiler.
Is a single tank with multiple coils or "tank-in-tank" better for me?
Or if I had two separate tanks can one be mounted on top of the other (2.4m floor to ceiling height). I can accomodate up to approx 700mm diameter tank.
Any comments/suggestions would be great. Thanks

dj01 · 12-01-2011 03:34PM

Indeed Freddy yet another Heatpump fan here to dispell the myth we're all off lighting bonfires. My air source heat pump with UF heating kept our house very toasty during the big chill, happy to say the coldest I got was opening the fridge!

Look's like most people's heatpump's did a pretty good job, and as the other poster said, machines do take a break from time to time. If only my car was as reliable as my heat pump!:D

freddyuk · 13-01-2011 12:20AM

I am pleased there are systems out there that are working. We have some posters that have published figures for their running costs which is what people really want to know to make an informed decision providing those figures are verified.
I have seen some very interesting developments in the UK where the electricity supplier tariffs have been geared towards off peak usage which makes HP technology much more viable.
It does not mean that Airtricity or ESB will follow suit but the market in the UK will expand rapidly on the back of this which will tend to make the technology cheaper for the customer in UK and quite possibly Ireland.
I have half an old drafty house and half a new well insulated house and the difference is remarkable. UFH is brilliant if you use it correctly. You can connect up the old and new quite easily.
For the record I have just ordered an Air to water HP and will be looking forward to experimenting.

Plombier · 13-01-2011 12:37AM

Just to add my bit, if you look back through the posts over the cold spell I think there was one HP that failed but I'm not going to count the number of oil and gas boilers that have, Freddy what are the details of the HP you have ordered and how did you select it ?.

www.ecofitter · 13-01-2011 06:49PM

Hi , just adding to the thread.
Air source HP are much cheaper and easier to install than GSHP. However the efficiency drops dramatically as you get closer to freezing , around -7 they stop working effectively as heat pumps, ( i.e extracting more heat from the atmosphere than power you put in)
Ground Source works better at these temperatiures as you are extracting the heat from 1.2m underground at around 10degrees even on the coldest air temperature day ... However installing an exterior ground loop does in my experience as a fitter double the installation costs... so how maany days at -7 are you going to have regularly when the heat pump will not give you the extra ( above 100%) effectiveness... probably not that many in Cork .. nice and toasty there by the gulf stream.. So take the plumbers advise from the start of the thread INSULATE INSULATE AND THEN INSULATE to about 350mm in the roof , install the heat pump and certainly the solar hot water
( even retro fit into old rads and I have a system I have used for this)
Solar hot water for me in sunny scottish hill farm where its been all nice and white and clean since November not so good on the solar ... but from March to September it does pretty much all my hot water...
and the heat pump heats the house... which given we retained the old oil boiler and its now .. well broken... is a good thing.
If you can please try to produce your own power ( best from wind on a tower not house mounted turbine) , and it sounds like you have a nice flat roof for solar hot water ..
good luck with the build... both Navitron and Dismy have kits for self install please have a look as they are a good baseline price to guide you , feel free to mention me as I have bought from both.
cheers

parkman2010 · 13-01-2011 07:19PM

Hi jimmyging,
I had the same problem as yourself except multiply by two. Have replaced compressor twice and I know the company you are referring to have gone bust. They have just fixed my unit for the second time. Apparently electronic unit overheated, and burned out and this led to valve damage in the compressor. I had to put serious pressure on manufacturer to get it fixed. Whats your situation now?

freddyuk · 14-01-2011 12:37AM

Plombier wrote: »

Just to add my bit, if you look back through the posts over the cold spell I think there was one HP that failed but I'm not going to count the number of oil and gas boilers that have, Freddy what are the details of the HP you have ordered and how did you select it ?.

I have gone to the manufacturer that supplied my Solar thermal kit. Nasty Chinese stuff but I am a big fan of quality Far East equipment.
It is an all in one unit designed for a 300 L tank up to 55c. Specified COP = 3.2. We plan to try and boost performance with solar as this is the key, ie. using as little grid electricity as possible. I think this is one way forward and lots of chat going on regarding this subject.
If it works for my domestic situation it will fit the bill for many rural properties. Only one way to find out.
If you would like full details feel free to PM me.

Will report when we have some results; good or bad.

housebuilder1 · 14-01-2011 02:35AM

Hi guys,

The most common reason for compressor failure is that most heat pumps installed in Ireland are way over sized. This leads to a frequent "start / stop" operation of the compressor. This will reduce the life of the compressor hugely. ive seen them go after 3 - 5 years because of this problem...

Heat pumps like to be running, they like to be left alone and not be over controlled by too many controls. This could also be the reason for compressor failures...

eg. house is 2500 Sqf (235 m2 approx) most guys would say maybe a 12kw - 16kw heat pump with stats in all the rooms... THIS IS MAD... a standard house to Part L 2008 would not need any more than 6 - 8 kw heat pump... this would ensure nice long runs on the compressor and a long life too... most modern heat pumps will also NOT need a buffer vessel if sized correctly. Most good modern heat pumps have full weather compensation, i.e the colder the weather the hotter the floor or rads (yes rads are fine too). Older type machine with NO full weather comp simply have to have a buffer...

Stats will only mess up the CPU weather compensation and cause the heat pump to start / stop too often and also to have higher running costs. Sats should only be used in room you want COLDER i.e bedrooms....

Heat pumps need a min volume of water to cool the hot gas coming from the condensor with a typical delta T of 8 degC. To get this a typcal heat pump needs between 10 - 15 Ltrs of water per Kw output, so if you insist on stats for some strange reason with a heat pump that has full weather comp then u will need a buffer of ( Xkw times 15Ltrs... )

i could go on and on about heat pumps and how the are controled incorrectly in this country... but i wont drive yee all away.. lol..

This experience is coming from having installed / supplied over 1,000 heat pumps so ive made my mistakes and learned fairly quickly the do's and dont's with these machines...

Simple "install me and leave me the hell alone" works best... Oh ya a good experienced installer with good back-up is vital too....

Cheers

mike

heinbloed · 14-01-2011 10:44AM

It might be of interest that HP compressors loose their refrigerant at all times. Even the large fluorine molecules pass through, these are much larger than the modern refrigerants. The smaller the molecules are the faster this process of diffusion happens.

Therefore the HP needs anual checks, at least anual checks. By qualified personal who are able to handle leak detection equipment. And who are literate.
This anual check is part of the guarantee of the manufacturers.
The owner of the HP is responsible to run a " log book " where the maintenance is documented, it is up to him to proove that the inspections - legally required or not- are recorded.

See also:

http://www.fluorocarbons.org/en/debate/regulatory_developments/f_gas_regulation.html

The plug and play advise by those claiming to have installed already thousands of HPs is wrong and shows an absolute disregard to consumers rights, economics and our legal system.

See also here for the legal requirements of the owner:

http://www.bis.gov.uk/files/file31943.pdf

Quote:

" Record Keeping
Operators of the stationary applications referred to in article 3.1 containing
3kg or more of F gases will also have to maintain records on the quantity and
type of F gases installed, any quantities added and the quantity recovered
during maintenance, servicing and final disposal. They shall also maintain
records of other relevant information, including the identification of the
company or technician who performed the servicing or maintenance, as well
as the dates and results of the leakage checks and relevant information
specifically identifying the separate stationary equipment with more than 30kg
of F gases. These records will have to be made available on request to the
competent authority and the Commission. "

housebuilder1 · 14-01-2011 10:45PM

Great advise there. And yea heat pumps do loose a certain amount of gas. I have had to get maybe 4-5 heat pumps re-gassed.

The most important thing like is said above is to make sure you get a good fridge guy. A really good one at that. Is very important that the circuit be evacuated, weighed, tested and refilled properly. Over filling is almost as bad as not enough so make sure u have the manufacturers guide as every type of heat pump does not have the same amount or type of gas.

Getting an average fridge guy will only mean getting a better one back again and paying on the double.

Heat pumps are fairly bullet proof once installed and commissioned properly and most problems are minor. Refrigerant should not be tried by beginners as the machine will never work properly or efficiently after.

Only go by the guides of the previous post.

Well done. Good post.

Mike.

jimmyging · 19-01-2011 12:31AM

parkman2010 wrote: »

Hi jimmyging,
I had the same problem as yourself except multiply by two. Have replaced compressor twice and I know the company you are referring to have gone bust. They have just fixed my unit for the second time. Apparently electronic unit overheated, and burned out and this led to valve damage in the compressor. I had to put serious pressure on manufacturer to get it fixed. Whats your situation now?

parkman,

we have just had the compressor replaced and system is running perfectly again.Our problem seems to have been that our plumber told us to leave the hp to ON constantly when it should have been on auto as we have room stats and a buffer tank.this means that the hp was overheating and tripping itself out all the time so it was only time til it burned itself out..it seems to have been running on average 16 hours a day and since it has been fixed it is between 2-4 hours /day in the cold .I hope this sorts it out and that your problem is solved pman.
jimmyging

housebuilder1 · 19-01-2011 02:22AM

Hi. Glad to hear it's working well now. Can I ask you a question about your heat pump. Does it have weather compensation or just controlled by stats etc...

If it has weather comp try disconnecting the stats and you will find the machine runs even better.

Stats may cause heat pumps to start / stop too often causing eventual compressor failure.

Hope it runs good and for long years to come now for you.

Mike.

jimmyging · 20-01-2011 12:15AM

housebuilder thanks for the advice but i dont have weather comp as far as i know but have room stats and a buffer tank which i have since heard are not the most efficient but i will keep a close eye on it .Is weather comp just another stat ?
again thanks for info
jimmyging

Indieman · 20-01-2011 01:25AM

Hi, very sorry for jumping in on this thread but I have a quick question. I'm in the process of buying a 2600sf house with oil burner & underfloor all round. The house has been left idle all winter and I'm afraid the -14 frost has damaged the system ( burst pipes). Is there a way of testing the system???

housebuilder1 · 21-01-2011 02:38AM

Jimmy. It's not a stat as such. It's an outdoor sensor linked to a controller that has several heating curves. Say it has 20 different curves. Curve one would represent a house with an extremely low heat loss while curve 20 would be crap like living in a shed. Lol. Most houses should be in between 1/2 and 1/3 way from bottom.
The curve is plotted in a graph. The x axis on the bottom is outdoor temp with zero approx half way. To the left is warmer. To the right colder. The y axis on vertical is flow temp. Zero on the bottom getting hotter as it rises.
As the outdoor temp gets colder the flow temp will rise according to the heat loss curve you have selected that best matches your house. This does need tweaking over a few weeks. Also as it gets warmer outside the flow temp reduces.
The affect in the house is a nice constant temp with no cold areas and ZERO reaction times as the floor is always on and always adjusting.
There is never a situation such as a cold start in the morning causing massive energy to get floor or rads unto temp quickly.
Weather comp can also be called floating condensing or non steady state.

Hope that helps. It takes a bit of getting your head around it but when you do it's brill.

Retro fitting is possible but can be complex.

Ta

Mike

housebuilder1 · 21-01-2011 02:45AM

Indieman.

Oops. I've seen this happen so many times mate. It's not an easy one to sort in an existing house. Depends on where the leak is etc.

Only sure way is to pressure test before you purchase. It may cost a few hundred to get a lad out to test but may save you a lot more inthe end. Or it may put your mind at ease buying your home.

I think you may be lucky as the house is somewhat sealed and is not open to the severe frost but no harm in putting your mind at ease.

Let me know how it goes.

Best of luck in new home. Hope no leaks and all goes well.

Mike

freddyuk · 22-01-2011 12:45AM

housebuilder1 wrote: »

Indieman.

Oops. I've seen this happen so many times mate. It's not an easy one to sort in an existing house. Depends on where the leak is etc.

Only sure way is to pressure test before you purchase. It may cost a few hundred to get a lad out to test but may save you a lot more inthe end. Or it may put your mind at ease buying your home.

I think you may be lucky as the house is somewhat sealed and is not open to the severe frost but no harm in putting your mind at ease.

Let me know how it goes.

Best of luck in new home. Hope no leaks and all goes well.

Mike

A few hundred??!! It is very unlikely the U/F has been affected by frost it would be the copper system elsewhere that would suffer damage. Is the system leaking / empty? A leak above ground would be fairly obvious.
If it is pressurised system it should be easy to check if it is holding pressure. If it is open vented then a few checks and procedures will allow you to pressure test it.
Anyway we have hijacked a thread so apologies OP.

housebuilder1 · 22-01-2011 01:28AM

i mean a few hundred as in 200 or so if a leak needs to be found. if its a simple sealed system with fill valve then it will only take 5 min to see if it hold pressure. you could do that easy your self...

if the pipe is in a screed it can burst as easy as above ground. we had a house under air test before xmas and when plumber came back after xmas he filled and vented the system with water. when he cam back a few days later to turn heat pump on the weather got cold again and when discovered pressure was gone, presumed it may have been air but no, a pipe in the screed had frozen and burst. i dug it out and there it was. amazing how it went, it was in middle of house and all... wierd or what. although water freezing has far more pressure that one may think...

All im saying is that for peace of mind it would be easy to pressurize floor and if pressure drops to call a guy out to hopefully find it.

Indieman · 23-01-2011 04:34AM

Is it possible to pressure test a complete working system? I have an idea as to how underfloor works so can all the valves be open at once in the entire house to check everything? There is a stat in every room and space

parkman2010 · 24-01-2011 09:16PM

jimmyging wrote: »

it seems to have been running on average 16 hours a day and since it has been fixed it is between 2-4 hours /day in the cold

Hi jimmyging,
Thanks for your reply, Ya I have my system fixed again thankfully, though it is still not working 100% yet. Just regarding the quote of 16 hours per day and such. I was just wondering what is the average amount of hours a heatpump should be on in weather of about 0 degrees. I know there are alot of variables for this and such.

You say that you have it on for 2-4 hours per day, is this sufficient to keep the house temperature topped up? What temperature do you aim to have in your home? Sorry for all the questions, just nosy!!

jimmyging · 24-01-2011 10:56PM

parkman2010 wrote: »

Hi jimmyging,
Thanks for your reply, Ya I have my system fixed again thankfully, though it is still not working 100% yet. Just regarding the quote of 16 hours per day and such. I was just wondering what is the average amount of hours a heatpump should be on in weather of about 0 degrees. I know there are alot of variables for this and such.

You say that you have it on for 2-4 hours per day, is this sufficient to keep the house temperature topped up? What temperature do you aim to have in your home? Sorry for all the questions, just nosy!!

parkman,

how do you mean it is not working 100 % yet ? is your average temp still low indoors .In answer to your question i dont know how many hours a day the heat pump should be working but ours has been working fine on about 4 hours a day since it was fixed .my brother has the same type of system but having mixed results down to insulation i think.
:pac:

jimmyging · 24-01-2011 10:57PM

sorry didnt mean to put in that pacman..

annie gilpin · 31-01-2011 11:16PM

twenty8 wrote: »

It appears to me that most of the comments so far are from people with Geo and UFH. I have both and would not change. House is approx 3,500 sq ft and the missus loves her heat as too do the kids. It would cost another mortgage to heat this place via oil burner. With the geo I have a very warm and cosy house. At what cost??

Well my yearly electricity bills are roughly €1,400 which I consider reasonable. Don't forget that that cost also includes all my other electricity uses - lights etc etc.

I thoroughly recommend it - but as an earlier poster said there is a larger upfront cost - and you will have to review your budget against that. Any questions - don't hesitate to ask.

im also thinking on installing geothermal.im about to start a new build in donegal.was wondering what tipe of heat pump you have in and what size it is? thanks annie

Pumping Heat · 06-02-2011 12:05PM

I am stunned at the sheer ignorance being displayed about Geothermal underfloor heating, wind and solar energy. obviously "information" being gleaned from the Ph.D of the Bar stool or Dinner Party.

Fact: You need to Keep the heat in and control the levels of heat.
Fact: The number of KW/Hrs needed to heat the house is common to all sources.
Fact: Condensing boilers cease to condense when the return temperatures rise so the "extra efficiency" is not continuous.
Fact: Solar water heating is very green and free in use but still very uneconomical.
Fact:Wind energy in smaller applications is still financial lunacy.
Fact: The difference in cost between modern Air source and ground source geothermal is such that the air source installed correctly in a properly constructed house is the most economical source of home heating at present and will become more so as time goes on.

heinbloed · 06-02-2011 07:43PM

Pumping Heat wrote:

Fact: Condensing boilers cease to condense when the return temperatures rise so the "extra efficiency" is not continuous.

There are modern boilers available which do use the condensing modus AND have a high return temperature. Alas they start at 12 kWh min. output, better suited for larger building/high thermal energy demand.

See here:

http://www.ryll-tech.de/l1/index_l1.html

There are more:

http://www.vollbrennwerttechnik.de/hersteller/hersteller.html

Click onto the www. adresses, text mostly in German. But check the web for more, I'm sure there is a good deal available.

About the

Fact: Solar water heating is very green and free in use but still very uneconomical.

: ST heating can be economical, a price for thermal energy of 3-6 kWh can be guaranteed and charged and profitable.

See here:

http://www.solar-district-heating.eu/Home.aspx

and in particular for detailed prices and economics the Marstall project:

http://www.solar-district-heating.eu/Home.aspx

All sums checked! And the HP from 1 MW (!) onwards is economical. Smaller, ones (maybe 1 for each costumer ) aren't worth it.

As said in the Marstall reports: 3 cents/kWh are the target.

A Danish participant in the Marstall project ( Arcon ) can guarantee 3-4 cents according press releases.

Geothermal and UFH Vs Oil and Rads

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