navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address - following recent spam/hack attempts on the forum, all security is set to "high", and "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: 1 2 [3]   Go Down
  Print  
Author Topic: Air or ground source + solar  (Read 9049 times)
neilydun
Newbie
*
Offline Offline

Posts: 22


« Reply #30 on: May 18, 2010, 07:50:00 PM »

Thanks billie, not forgeting I don`t really know what i`m talking about, and thats why I originally posted on here---

If I was to have about 25 Sq. M of solar thermal on my roof, in the winter that (might) be enough to heat my underfloor, and water.
In the summer that would be oversize, and someone posted earlier I would probably have to dump up to 75% of heat produced.
So, if I dug out for a GSHP, during the summer months could the process be reversed, and the excess heat produced from the solar, be dumped back into the earth?
Either via running the GSHP in reverse Huh or running another pipe alongside the collecter???

Like I say I don`t know if i`m talking out of my a*** its just I hate to think of 75% of what is produced during the summer months going to waste, and I dont have enough room to build a lake in my garden, it looks lovely by the way !
Logged
martin
Hero Member
*****
Offline Offline

Posts: 15733



WWW
« Reply #31 on: May 18, 2010, 08:24:20 PM »

There are all sorts of arcane schemes to use solar to heat homes in winter, to be frank, it's all usually a colossal expenditure for very little return (it's that "law of sod" again) - when you  most need the heat, it ain't there......... Most people end up with a pragmatic April - October heating of domestic hot water by solar... Wink
Logged

Unpaid volunteer administrator and moderator (not employed by Navitron) - Views expressed are my own - curmudgeonly babyboomer! - http://www.farmco.co.uk
dhaslam
Hero Member
*****
Offline Offline

Posts: 6775



« Reply #32 on: May 18, 2010, 09:01:49 PM »

Thanks billie, not forgeting I don`t really know what i`m talking about, and thats why I originally posted on here---
So, if I dug out for a GSHP, during the summer months could the process be reversed, and the excess heat produced from the solar, be dumped back into the earth?
Either via running the GSHP in reverse Huh or running another pipe alongside the collecter???

I think that the problem with the  GSHP coils is that they are normally spread over a large area this allows the pipes to pick up some natural heat from the ground in winter.   The problem is that being spread out they would also lose heat as well.    It would be better to have a more compact storage area separate from the  normal collector.    I am using above ground store because the ground is very rocky but it would be possible to store the heat underground if there is insulation, at least on top.   
Logged

DHW 250 litre cylinder  60 X 47mm tubes
Heating  180,000 litre straw insulated seasonal store, 90X58mm tubes + 7 sqm flat collectors, 1 kW VAWT, 3 kW heatpump plus Walltherm gasifying stove
daftlad
Hero Member
*****
Offline Offline

Posts: 1732



« Reply #33 on: May 18, 2010, 09:15:16 PM »

There are all sorts of arcane schemes to use solar to heat homes in winter, to be frank, it's all usually a colossal expenditure for very little return (it's that "law of sod" again) - when you  most need the heat, it ain't there......... Most people end up with a pragmatic April - October heating of domestic hot water by solar... Wink

Except if your house is designed to work as a passive solar heater, they work very well, even in the UK.
It is possible to heat your home with virtually no fuel, even in the UK.
ta ta
Logged

I WILL KEEP BANGING ON ABOUT MASONRY STOVES
MR GUS
Hero Member
*****
Offline Offline

Posts: 3405


Officially "Awesome" because Frotter said so!


« Reply #34 on: May 18, 2010, 09:15:39 PM »

Went to avail myself of mispriced goods @Tesco's (spit) yesterday basically buy 1 get 14 free  whistlie
The tarmac in the carpark was sizzling, shame theres no  GSHP layed down in Englands car-parks, they DO HAVE ROOM after all to at least make a contribution.
Logged

Austroflamm stove & lot's of Lowe alpine fleeces, A "finger" of Solar Sad
Noli Timere Messorem
Screw FITS
Leaf Owner (1st gen)
billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8944



WWW
« Reply #35 on: May 18, 2010, 09:16:02 PM »

Billi

neilydun  ... nearlydone  

It is the same pipe work , the surplus of the overspec solar  is pumped into (example) ground store and then the heatpump  benefits in higher COP of the preheated ground , or the heatpump does not need to work at al cause solar is providing heat


Billi

PS :
Quote
There are all sorts of arcane schemes to use solar to heat homes in winter
 that work fine  Wink
Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
neilydun
Newbie
*
Offline Offline

Posts: 22


« Reply #36 on: May 18, 2010, 09:30:36 PM »

Can`t knock Tesco (spit spit) at the mo. My HiLux runs on veg oil and Tesco has been punting it out at 42p a litre.
Happy days !
Logged
MR GUS
Hero Member
*****
Offline Offline

Posts: 3405


Officially "Awesome" because Frotter said so!


« Reply #37 on: May 18, 2010, 09:37:13 PM »

That's it though use em & abuse em, we simply take advantage of specific deals then Heinz off to waitrose for a proper shop with quality food.

 However the deal on cartons of chopped  (multi flavour) tomatoes are working out ideal for  batch cooking spags for the nipper & vacuum sealing.
System glitch, that gives you a moneyback reduction too, thought it had been fixed.
 If I see a cheap veg oil deal I'll remember to put it here!
Logged

Austroflamm stove & lot's of Lowe alpine fleeces, A "finger" of Solar Sad
Noli Timere Messorem
Screw FITS
Leaf Owner (1st gen)
billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8944



WWW
« Reply #38 on: May 18, 2010, 09:40:20 PM »

Quote
My HiLux runs on veg oil and Tesco has been punting it out at 42p a litre.
Happy days !


 Grin have to check prices here again cause my Pick-up is converted as well
Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
neilydun
Newbie
*
Offline Offline

Posts: 22


« Reply #39 on: May 18, 2010, 09:44:17 PM »

Offer finished yesterday I think. I will post any others I hear of.
Was on a BOGOF
Logged
martin
Hero Member
*****
Offline Offline

Posts: 15733



WWW
« Reply #40 on: May 18, 2010, 10:21:14 PM »

I'll reiterate what I said - despite the best efforts (via Tesco) to go completely off track, yes it is possible to concoct schemes involving hundreds of solar tubes, thousands of litres of insulated storage, heat pumps, and doubtless several donkeys in treadmills too......... yes, it's possible to heat a home using solar in the UK -it's also possible to build a passivhaus, and use virtually no input of energy all winter.......... BUT, down here in the real world, we have someone with a barn conversion, with not an enormous plot of land, who's looking for possible, practical ways to heat his home............. Roll Eyes
I always take questions like this seriously, and apply "what would I do in his shoes" to it.... I doubt there are bottomless pits of money to be wasted, and we're "starting from where we are"....... to that end, my recommendations to minimise outlay, both on putting in the system and running it would be along the lines of solar DHW for the summer months, wood/oil for the winter, having taken all reasonable measures to insulate as well................. simple, relatively inexpensive, reasonably "future proof" - boring but pragmatic! ralph
Logged

Unpaid volunteer administrator and moderator (not employed by Navitron) - Views expressed are my own - curmudgeonly babyboomer! - http://www.farmco.co.uk
billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8944



WWW
« Reply #41 on: May 18, 2010, 11:21:06 PM »

 
Quote
boring but pragmatic!
Pragmatic in my point of view is  10 kwP of PV installed  for 25000 $ and a heatpump then  Grin

Billi


And get the grants or the FIT  Tongue  , and why should i need any solar tubes then  Roll Eyes , just joking  laugh

But  even without any cash help and of grid i think of that

Billi
« Last Edit: May 18, 2010, 11:45:18 PM by billi » Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
Bodidly
Hero Member
*****
Offline Offline

Posts: 1527



« Reply #42 on: May 19, 2010, 08:58:22 AM »

A word of warning on underground thermal storage with heat pump.
I have a 6kW ground source heat pump. I regularly monitor the temperature of  the incoming ground loop. During the winter this temperature will tend to slowly drop away due to cooling of  the ground near the loop but after periods of heavy rain the ground  temperature will return to near 10degrees in a mater of hours. This is great in winter but if you had raised your underground storage to 15degrees and this went down to 10degrees in a mater of hours not so good.

So I would recommend that any underground heat store is protected from the ingress of ground water.
Logged
rt29781
Hero Member
*****
Offline Offline

Posts: 1247


« Reply #43 on: May 19, 2010, 12:44:49 PM »

We have 150 tubes on a sw facing roof in SW France and get heat into the house most of the time.  We top up with heat from an air to water heat pump and this next year we will have our woodburner working.  On the really cold cloudy days there is obviously no solar and there is very little heat coming from the heat pump (anything below freezing and the heatpump struggles).  So on real cold cloudy days use the woodburner or take a hit on the electricity cost.  On cold clear days (even in a howling gale) the solar thermal heats the house no issues.  It depends where you live and how much cloud you have as to whether solar thermal will be worth it for you.  If I were to start again, and was bothered about the cost, I would just make the whole roof a solar collector.  Simple black plastic tubes with a polycarbonate cover and take the output straight into the floor using a variable speed pump controller to get the temperature constant (40C) for the floor.  I cannot fault the Navitron solar tubes but they are expensive and we have a massive roof area so we have choices.  However the solar heating system is very easy to manage.  In summer there is excess heat and that continues to be an issue.  We were also in a dilemma about choosing an air or water source heat pump.  We inherited 2 air to air heat pumps and they work well but don't heat the floor area so you end up with a warm head and cold feet.  We went for an inexpensive Trianco air to water heat pump which although rated at 12kW only puts out 6 to 9 kW when it is required.  It does munch electric (2.6kW/hr) but it was a breeze to fit and complements the solar heating.  We also like the house warm (23C) as we live in SW france we are used to being warm now. Use the house floor as the storage system as much as you can.  We have a storage tank which is a 500lt plastic bucket in 1 tonne of concrete and this captures excess heat from the system in the day and puts it back into the house in the evening.  We did try seasonal storage by pumping excess summer heat into the ground under our pool but killed one of our trees so stopped doing that.  We spend very little ongoing on heating now but have to recoup about 6000 for the heat pump and solar tubes.  I doubt we will use the woodburner for more than a month in winter.  We will probably use the heat pump for another month and the rest of the time we will use solar.  It is a long term investment even in the south of France.  However today it is cool and windy outside but very cosy inside for 170m2 house.  It is quite cloudy but there is enough sun to heat the house.  I hope this helps.
Logged

Nowt currently, Aberdeen.....well actually very well insulated extension with passive solar that seems to heat the house....
neilydun
Newbie
*
Offline Offline

Posts: 22


« Reply #44 on: May 19, 2010, 04:21:27 PM »

I just wanted to say thanks to everyone who`s posted a response.
I`m not sure i`m that much clearer, but its good to hear different people`s opinions, experiances, and I will try and take as much as possible on board.
Thanks again !
Logged
Pages: 1 2 [3]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!