Ground Source Heat Pumps

JHen1

beardymarrow said:

JHen1 said:

They are def in the correct order

That doesn't make sense then. It's saying you'd used 28529Hrs up until the 11th March, but then a day later you'd used 9hrs less than that in total. Unless your GSHP is also a time-machine that's not possible :-)

These are 100% correct. Please note the figures are reported a negative numbers, which confused me at first.
Perhaps it's just the way my IVT reports these.
I'll check the unit for a door, just incase it is a time machine

beardymarrow

Ah. Gotya! Curiouser and curiouser. I can only assume that the variable that stores those values is a signed 2 byte integer in the internal register and it has been on for so long that it has rolled over to negative and so it's now counting back up from -32768 towards 0.
Oh well, either way they look about right.

lstevensuk

beardymarrow said:

lstevensuk said:

Something strange has happened! I thought I would switch everything back on for the week so I can monitor total hours etc. I've  checked everyday and I've not lost a single drop  This thing has been loosing it every week for months and suddenly after switching back off and on nothing!

Wonderful. To me that sounds very much like you were losing it around valves you turned off and on, and the action of turing it off and on again has just moved things ever so slightly. Either that, or the colder weather has caused the ground to contract ever so slightly and take a tiny bit of pressure off whatever underground joint was leaking.

Ok bad news! It's leaking again (and quite a bit). I went through turning loops off again and yup one of the loops does have a leak!

Has anyone seen or heard of this stuff being used > geo loop leak seal> : 

http://geosystemsusa.com/geothermal/geo-loop-leak-seal-and-conditioner/


Other from that where would I start digging: Thinking of digging a ditch across the grass section to at least find the pipes. There is a funny patch of grass in the middle, however not sure the leak will make it that far up. Or I could start with the tarmac near the manifold, a bit of a dip has appeared just outside it.

I could always start a spot the leak competition

beardymarrow

lstevensuk said:

beardymarrow said:

lstevensuk said:

Something strange has happened! I thought I would switch everything back on for the week so I can monitor total hours etc. I've  checked everyday and I've not lost a single drop  This thing has been loosing it every week for months and suddenly after switching back off and on nothing!

Wonderful. To me that sounds very much like you were losing it around valves you turned off and on, and the action of turing it off and on again has just moved things ever so slightly. Either that, or the colder weather has caused the ground to contract ever so slightly and take a tiny bit of pressure off whatever underground joint was leaking.

Ok bad news! It's leaking again (and quite a bit). I went through turning loops off again and yup one of the loops does have a leak!

Has anyone seen or heard of this stuff being used > geo loop leak seal> : 

http://geosystemsusa.com/geothermal/geo-loop-leak-seal-and-conditioner/


Other from that where would I start digging: Thinking of digging a ditch across the grass section to at least find the pipes. There is a funny patch of grass in the middle, however not sure the leak will make it that far up. Or I could start with the tarmac near the manifold, a bit of a dip has appeared just outside it.

I could always start a spot the leak competition

Oh, that's a shame. I'm sorry I've not got any experience of finding or fixing a leak myself. If it was me though I'd definitely give that stuff a go to save the time and expense of digging everything up. Worth a try in my book.
Alternatively and I know it's obvious, but the leak is most likely around a joint, rather than a pipe itself. I think from memory you've got cassettes, so there'll be loads of joints, not like a slinky, so it could be anywhere. I have read that companies can take the glycol out and replace with a gas and then use a gas detector to find where it is coming out of the ground. Take a look here for more advice.
Good luck and keep us updated.
Beardy

lstevensuk

Thanks, I looked into the gas detector but it was going to cost nearly £2k! I'll give that stuff a try first and maybe dig the ditch at same time so I at least know where the pipes/cassettes are and how deep

edwh

Does anyone have any experience with using a heat pump with a traditional boiler backup?

As I understand it, if a heat pump can't operate efficiently it will switch over to just using electricity to heat the water, which can prove expensive.  What I'm wondering is whether we can fit a heat pump system which switches over to an existing oil boiler if the heat pump is not operating efficiently.  I think that probably rules out any subsidies, but I'm ok with that.  I'm aware you can get hybrid systems but I'm wondering whether you can retrofit.

We currently have an Worcester oil boiler which is around 5 years old.  When we initially got quotes for heat pumps (also around 5 years ago), they were quoting a 30KW system.  We have land which would work for a GSHP, and I would love that very much, but I can't afford the capital cost, so I'm considering an air ASHP.  It's an old property which is hard to insulate well, though we've made improvements in that area with more to come, but that's part of why I'm concerned to minimise the risk.

beardymarrow

edwh said:

Does anyone have any experience with using a heat pump with a traditional boiler backup?

As I understand it, if a heat pump can't operate efficiently it will switch over to just using electricity to heat the water, which can prove expensive.  What I'm wondering is whether we can fit a heat pump system which switches over to an existing oil boiler if the heat pump is not operating efficiently.  I think that probably rules out any subsidies, but I'm ok with that.  I'm aware you can get hybrid systems but I'm wondering whether you can retrofit.

We currently have an Worcester oil boiler which is around 5 years old.  When we initially got quotes for heat pumps (also around 5 years ago), they were quoting a 30KW system.  We have land which would work for a GSHP, and I would love that very much, but I can't afford the capital cost, so I'm considering an air ASHP.  It's an old property which is hard to insulate well, though we've made improvements in that area with more to come, but that's part of why I'm concerned to minimise the risk.

Hiya,
The GSHP won't switch over to using just electricity, it will just boost the GSHP with additional electricity (for example when it's really cold ad it can't meet the heat demand solely using GSHP). For example in the depths of winter ours will have the compressor on pretty much permanently, and occasionally the 3kW, 6kW (or both) elements will kick in as well just to get it that last couple of degrees. I can choose how long that delay is and whether to allow 3, 6 or 9kW to get best efficiency.

A 30kW system seems large. We've got a 5 bed detached 3 storey house and our system is an IVT E11 (so 11kW output), with rarely the additional electric of up to 9kW, but it is very well insulated and partly underfloor heating. Maybe if your insulation is not great that's why they're suggesting a large system. Might be better long term to spend some money on insulation and then be able to get a smaller system?

The Worcester Bosch GSHPs have the option of an additional traditional boiler (see section 8.4 of this manual) but I really wouldn't bother for the amount of time that it would be on, on a properly sized system.

Regarding GSHP vs ASHP, I know ASHP has come on a bit, but in my view they are not as efficient, noisier, and can ice up and if you've got the space for GSHP, then that would be the way to go. I do have a beef though as our neighbour has one which is virtually underneath our bedroom window, whereas we have a nice quiet GSHP :-)

Juleszoemay

We had a ASHP with a gas boiler back up (Hybrid) I say had, as the ASHP failed at just over 2 years old, filled up with water inside and died. So we are now using the gas boiler only in emergency mode, sighs....
I don't know if you can get a hybrid GSHP/Boiler though. 

beardymarrow

Juleszoemay said:

We had a ASHP with a gas boiler back up (Hybrid) I say had, as the ASHP failed at just over 2 years old, filled up with water inside and died. So we are now using the gas boiler only in emergency mode, sighs....
I don't know if you can get a hybrid GSHP/Boiler though. 

You can definitely get a GSHP that will trigger an external conventional boiler (Bosch one above is an example).

lstevensuk

beardymarrow said:

lstevensuk said:

beardymarrow said:

lstevensuk said:

Something strange has happened! I thought I would switch everything back on for the week so I can monitor total hours etc. I've  checked everyday and I've not lost a single drop  This thing has been loosing it every week for months and suddenly after switching back off and on nothing!

Wonderful. To me that sounds very much like you were losing it around valves you turned off and on, and the action of turing it off and on again has just moved things ever so slightly. Either that, or the colder weather has caused the ground to contract ever so slightly and take a tiny bit of pressure off whatever underground joint was leaking.

Ok bad news! It's leaking again (and quite a bit). I went through turning loops off again and yup one of the loops does have a leak!

Has anyone seen or heard of this stuff being used > geo loop leak seal> : 

http://geosystemsusa.com/geothermal/geo-loop-leak-seal-and-conditioner/


Other from that where would I start digging: Thinking of digging a ditch across the grass section to at least find the pipes. There is a funny patch of grass in the middle, however not sure the leak will make it that far up. Or I could start with the tarmac near the manifold, a bit of a dip has appeared just outside it.

I could always start a spot the leak competition

Oh, that's a shame. I'm sorry I've not got any experience of finding or fixing a leak myself. If it was me though I'd definitely give that stuff a go to save the time and expense of digging everything up. Worth a try in my book.
Alternatively and I know it's obvious, but the leak is most likely around a joint, rather than a pipe itself. I think from memory you've got cassettes, so there'll be loads of joints, not like a slinky, so it could be anywhere. I have read that companies can take the glycol out and replace with a gas and then use a gas detector to find where it is coming out of the ground. Take a look here for more advice.
Good luck and keep us updated.
Beardy

Quick update, managed to dig a trench across the garden (by hand) to a depth of 1.2m. Found nothing! As couldn't get it any deeper by hand decided to fill it in and think of something else. And would you believe it it stopped leaking again!! Must be something to do with the wetter ground, no idea. Anyway not a drop lost for a couple of months now!