Ground Source Heat Pumps

beardymarrow

lovesgshp wrote: »

Thanks for that info. Think you are going to have to wait for the engineer to arrive, as it is difficult to analyse some problems without being in front of the unit.
Hope you will update on his findings.

Engineer has been, and he was brilliant. Really patient with all my daft questions (as you have been) and very thorough.

3-way valve replaced with the newer LK Armatur sort (was an ESBE which he says he has had to replace loads of). He said even if wasn't suspect he'd have swapped it while he was anyway as the old ones were always going.

It certainly does look like the CH pumps were drawing DHW through them (and therefore through the rads and UFH) because the 3-way was allowing flow between A and B, when the HP was off (as opposed to the CH just circulating its own water through the bypass).

Return CH temp sensor was also moved to before the bypass instead of just as the return entered the HP, and a little leak on the ground loop fitting as it entered the HP was fixed.

The engineer said that there was no problem with it not having a pressure gauge or filling loop on the ground loop, and that the layout I had didn't need one as it had the expansion tank on, so that would keep the pressure correct, and it just gets filled from there if needs be.

The control unit software I've got is newer than the manual, which is why the DHW increase once per week is like it is (you can only specify daily, off, or the day of the week you want it doing). The older sort said how many days between boosts, and the even newer ones have other options for time of day and all sorts as well.

I'll let you know how the electricity consumption improves, as that's the whole point of the exercise (save money) :-)

Cheers

Beardy

lovesgshp

Hi Beardy.
Thanks for the update and info. Will be interesting to see if the 3 way valve does cure the problem, so look forward to hearing if the electricity consumption has dropped.
Must admit, that I found the explanation for no pressure gauge or refilling option very strange, as the expansion tank is just a vessel for expansion/contraction in the system. I have had to repressurise a few over the years and if you had a leak as well, then that would not have helped.
Just as a aside. Had a client call yesterday that they were getting a alarm showing. It was on the GT3 sensor (DHW) tank. A mouse had eaten through the cable, so they could not get any hot water. Temporary repair today, until new sensor arrives. Joys of living in the countryside!!!!

beardymarrow

Hi,
It has fixed it!

Before I loosened up the 3-way, I was consuming an average of 78kWh, with the HP on for 13.5Hrs per day


After I loosened up the 3-way valve, I was consuming an average of 53kWh, with the HP on for 10Hrs per day


After the 3-way was replaced, I have consumed 33kWh, with the HP on for 4Hrs in one day


I think there's some tuning I can do (such as switching the DHW off overnight), but I'm really happy now.

Thank you so much for your help lovesgshp and matelodave.

Beardy

lovesgshp

So glad it worked out OK with changing the valve, the old one must have still been sticking intermittantly, even after you had tried to clean it. Any other help you need, then please get back to us.

edwh

As mentioned some time ago on this thread, I'm looking at a GSHP but I'm struggling to find someone (in the Ribble Valley area) who wants to install it into an old house. They are concerned that the property can't be insulated well enough to avoid running up high bills when the electrical heating kicks in to top up the output when the return temperature is low.

As an alternative, one supplier is pushing thermopanels from Energie, and making quite bold claims for the COP (7!).

Does anyone have any experience with these?

beardymarrow

lovesgshp wrote: »

So glad it worked out OK with changing the valve, the old one must have still been sticking intermittantly, even after you had tried to clean it. Any other help you need, then please get back to us.

FYI - I've got a husdata H10 http://www.husdata.se/produkter.asp?prodid=2 on order now, so I can log the data coming out of my GSHP serial port. Should be interesting and will hopefully pay for itself in lower bills as I'll be able to tweak things a lot more easily and see the results at a really detailed level. I'll let you know how I get on if you've not used one before.

PS Had a sub 30kWh day this week :j! Very pleased with that.

lovesgshp

edwh wrote: »

As mentioned some time ago on this thread, I'm looking at a GSHP but I'm struggling to find someone (in the Ribble Valley area) who wants to install it into an old house. They are concerned that the property can't be insulated well enough to avoid running up high bills when the electrical heating kicks in to top up the output when the return temperature is low.

As an alternative, one supplier is pushing thermopanels from Energie, and making quite bold claims for the COP (7!).

Does anyone have any experience with these?

Get the thermal requirements of the house first of all, that is the priority. The pump will need to be sized correctly, usualy to a maximum of -10% of the heating requirement.
The house here is 250 years old, no cavity wall, but walls are 60cm thick. Altitude is 400 mtrs and close to the mountains. UFH, double glazed windows. No loft insulation as no loft, just straight to the main roof beams, with tiles, plus waterproofing, cork insulation, reinforced concrete for earthquakes and roof tiles.
Electrical heater assistance has only been for 35 hrs over 8 odd years, so that should not be a problem.
With regard to the thermopanels, I do not know them as they seem a relatively new idea and a COP of 7 could probably be in mid summer, as can find no data on them.

lovesgshp

beardymarrow wrote: »

FYI - I've got a husdata H10 http://www.husdata.se/produkter.asp?prodid=2 on order now, so I can log the data coming out of my GSHP serial port. Should be interesting and will hopefully pay for itself in lower bills as I'll be able to tweak things a lot more easily and see the results at a really detailed level. I'll let you know how I get on if you've not used one before.

PS Had a sub 30kWh day this week :j! Very pleased with that.

Good to hear that everything is running smoothly.
Have not used the H10, but looked at their video, unfortunately in Swedish and it appears to be a very good information unit. Very detailed and at least you can change settings from the PC as well. Keep me updated, plus a few more users would probably like to hear of the "tweaks" that you have managed with it once installed.

Patrol

Hello, just registered & could do with some advice both in terms of general efficiency but also whether these systems can get "stuck on". I've tried to put everything down I can think of.

My GSHP has been running for several years but today I find the house is far too hot and the pipes out of the unit are much hotter than normal, and despite this the ground loop is on. Turning it off briefly did the trick but I've had to switch it off a second time for longer while everything cooled down, seems to working OK after that but I'm wary of it happening again. I am now out of warranty and I turned down an "offer" for extended warranty at some eye-watering sum having never required it before.

IVT Greenline HT Plus E6 with separate IVT VB 300/160 cylinder.
2 x 34m x 1m x 1m trenches in waterlogged clay soil + sand bed.
Off-mains water supply (bore hole at approx mains pressure).
Eastern England.
185m ground floor, 55m upstairs.
3 bathrooms, gravity shower from dhw, family with 2 children.
Good insulation levels downstairs. Could improve upstairs eaves.
Built 2007, UFH downstairs, rads upstairs. No shunt valve.
External sensor on east elevation.
Internal sensor in downstairs hallway.
Thermostats in downstairs bedrooms.
I tried using the timer to switch it overnight for about 12-18 months before working out the cassette use went through the roof and it was more efficient to leave it on all the time.
Upstairs is slightly too cold but doors are shut and no thermostat other than radiator valves (which daughter has fully open...)

Annual readings for ground loop and cassette (6kw of 9kw?)
Installed & commissioned Nov-Dec 2007. On 24/7.
Dec 2008: 2709 / 84
Dec 2009: 4968 / 224 Timer switched unit off 10pm-6am at some point
Dec 2010: 6851 / 547 Switched back to 24/7 in April.
Dec 2011: 8243 / 666
Dec 2012: 10150 / 748
Feb 2014: 13324 871

1 Indoor temp settings.
1.1 Temp Incr / Decr range 0-10: 4
1.2 Temp fine tune range +10/-10: 0
1.3 Heat curve adjust (break):
Out / curve
20 / 20
15 / 23.2
10 / 26.4
5 / 29.6
0 / 32.8
-5 / 36
-10 / 39.2
-15 / 42.4
-20 / 45.6
-25 / 48.8
-30 / 52
-35 / 55.2
1.4 Heat curve hysteresis: 4
1.10 Setting of room temperature: 18.8 (just turned down from 21)
1.11 Setting of room sensor inf: 5
1.12 Setting of holiday function: 0 day
1.13 Remote control temp: Not acti
1.14 Setting of summer disc: 20.6

2 Hot water settings
2.1 Duration of add hot water: 0h
2.2 Interval for hot water peak: 7 days (I won't change this)
2.3 Setting of hot water temp: 50.0 (just dropped from 51)
2.4 Setting of hot water hysteresis: 4

3 Monitor all temperatures
Return Radiator GT1 on 8.0 now 32.8
Out GT2: 12
Hot water GT3 TGT 50.0 now 53.6
Room GT5 TGT 18.8 now 29.5
Compressor GT6 75.3
Heat trfluid out GT8 55.9
Heat trfluid in GT9 50.1
Heat trfluid (coll) in GT10 7.8
Heat trfluid (coll) out GT11 5.5

4 Timer control settings
4.1 Clock setting HP according to clock: All off
4.1.1: -2
4.2 Clock setting add heat acc to clock: mo 00:00 - su 00:00
4.3 Clock setting dhw acc to clock: mo22:00-06:00 - su22:00-06:00

6 Timer readings
6.1 DHW peak hour: 0 day 1h 46m
6.2 Read add heat timer: 0h 0m 0s
6.3 Read alarm times: 1h 0m 0s to 0h 59m 59s & back repeated
6.4 Read start delay: 0h 0m 0s

7 Operating time
7.1 loop 13943h
7.2 loop 31% dhw 69% rad
7.3 add heat 898h
7.4 add heat 45% dhw 55% rad

8 Add heat & mixed valve settings
8.1 Add heat timer: 60m
8.2 Block add heat: Not acti
8.3 Mixed add heat
8.3.4 Setting of ramp time open: 20m
8.3.5 Setting of ramp time close: 3m
8.5 Connected elec cap: 2/3

11 Alarms
3-4 alarms in Sep 2007, assume this is in-factory.
1 alarm on 26 Nov 2007 by supplier commissioner before he filled the ground loop.
Nothing subsequent to that.

Would be great for someone to make sense of all the figures.

lovesgshp

Hi Patrol and welcome.
Interesting figures!! Thanks for supplying all the data.
When you took the readings, were they on a heating cycle, or a DHW one, as they look like DHW.
1) Suggest you change summer disconnect to 18C as 20.6 is too high.
2) Time how long the DHW takes, from switch on to off. It should switch in about 2C below the target temp of 50.
3) Can you confirm that all the filters are clean, as GT10/11 look a little on the low side.
4) Remove the front cover of the pump and check when it is operating there are no air bubbles in the refrigerant sight glass.
5) Hold down the far right button on the control panel for approx 15-20 secs, until I/S menu is displayed. Go into 5 and select manual control of all functions and then 3 way valve. Use this to check the valve is fully opening and closing.
Let me know how you get on.