Ground Source Heat Pumps

akmodi

lovesgshp wrote: »

Don't worry about the newbie questions, sure we can cut the costs down somewhat.
Just one other thing as a afterthought. You should have 2 x pressure guages, one for the underfloor heating system which should be reading about 1.5 bar, and a second for the ground loop at about 0.5 bar, if you can confirm.
Thanks

Hi lovesgshp, Once again thanks for helping out.

I was told that if the house is fairly well insulated then -- the timing is not of use. The house is to be considered as a heat buffer and the "boiler" needs to get the house to the required temperature. Thereafter the house will loose heat dependant on the insulation.

By switching off the "boiler" we are only increasing the heat requirement when it comes back on -- Thus requiring the "immersion rod" to run, as it may cut in after the heat pump has run for a while.

PLEASE, correct me on the above as required.

I have thus not changed the timings, but correct me "as above"


The GT temps that you require are as follows:
The pump is idle, (I know you want these in the heat cycle, will come back then)

GT1 ON: 23.4 NOw: 27.5
GT2 7.6
GT3 Tgt 45 now 46.5
GT4 TGT 22 now 22.6
GT6 comp 35.7
GT8 28.1
GT9 28.1
GT10 17.7
GT11 10.7

I will need to come back with the GT readings in the RAD/heating cycle.

lovesgshp

Akmodi.
Please remember that we are not decreasing the room temperature by a significant level, by reducing the flow temp return, so if the insulation is good, it will not be that noticeable.
DHW reduction, will stop the pump switching in for say 8 hrs, and then with the DHW tank size will only probably need max 15 mins to reach temperature.
The immersion heater timer is normally set for a 60 minute countdown before it activates.
I think you said earlier that DHW is set at 46C, but it is showing on the GT3 sensor as 45C.
Hope you can get back to me with the sensor readings, as at the moment they do not show anything to analyse.
Thanks

akmodi

Hi lovesgshp,

Got the readings on the heating cycle

GT1 Off: 31.5 NOw: 26.5
GT2 7.5
GT3 Tgt 45 now 44.2
GT4 TGT 22 now 21.8
GT6 comp 69.8
GT8 33.7
GT9 27
GT10 1.1
GT11 -2.0

Once again, Thanks a ton for helping out.

I will be away for till next weekend, so will not be able to give you updates.

NB: I have done the timing changes suggested earlier

lovesgshp

Hi Akmodi.
Thanks for the info. If you have not left already, can you just give me the readings from K2 7.1 & 7.3.
Have a good week away, and we can see what effect those are when you get back.

akmodi

HI lovesgshp

Came in for a moment today,

The readings are as follows:
7.1 18841
7.3 2738

Thanks

akmodi

lovesgshp

Thanks Akmodi for that info. When you are back again, then we just need to have those readings again, plus your comments on how the house temps felt.
I have a number of thoughts, but those are better discussed when you return
As a aside, GT8-9 and GT10-11 are within set limits, so no problems with them.

akmodi

Hi lovesgshp

Am able read the forum -- in how many days do you need the readings?

The house did feel slightly cooler (not much and bearable).

As you can see in 7 days it has used 11 hours of extra heat - should have been about 2-3.

Its the extra heat that is the concern -- that's why I wanted to see if the bivalent part could be by a "gas boiler".

Is that possible ? Do' able ? Does it work well ? Tips and Tricks ? Is it worth it (if we can get the extra heat down to 2 hours a day)

Thanks

lovesgshp

Hi.
In answer to your question, the extra heat should be virtually nil.
I am putting a lot of the info you are giving me into a simulator that I have here, so there is more data that I need to feed in, as think there are possibly a few other adjustments that may have been made in the initial setup of the unit.
When you get back, then I need you to look at a number of extra readings in K2.
You can see the first ones in "heat curve adjust/break. At the setting of 4.5, then you should be looking at 30.8C at a outside temp of 5C.
If higher, then there have been some other adjustments, but we can look at those later.
Everything is possible and I would rather get your extra heat down to virtually nil, plus the pump working less than over 15 hours a day with a outside temp of 7C.
I can see what is happening from the GT10 inlet temp, that because of the high running hours, then it is not getting enough hours to recharge its heat level.

lovesgshp

"Is that possible ? Do' able ? Does it work well ? Tips and Tricks ? Is it worth it (if we can get the extra heat down to 2 hours a day)"

In answer to your extra heat question, bivalentsystem, re gas, this is the answer I had from our design engineers:
"In this case we have to check the wiring diagram and the type of Rego 600: with the earlier series Rego 600 was possible to choose the type of additional heating. With rego 637 instead you could disconnect the internal electrical additional heating to connect a gas boiler, but you can't use both, so in case of emergency you can't do domestic hot water, I suggest to install a small electric element in the DHW tank if possible."

To go back to the original high additional heat use, then my views are these.
1) The room setting @22C is high for a UF system. The norm is 19-20C. This is because a "radiant floor" is far more effective in providing heat evenly. In one of your earlier posts I see that the room temp was at 22.6C.
2) 4.5 on the heat level, is into radiator settings. This may have been set if you have heated towel rails, but would normally have been in conjunction with a buffer tank.
2a) At circa 16 hrs a day for the running hours on the pump, you are far too high, but this could be due to the house temperature setting. Suggest setting room temp influence to level 7, plus reduce to the earlier levels of say 20C.
3) Check the pressures as a earlier post, 1.5bar underfloor and 0.5 ground loop, as these can have a influence on efficiency and running costs.
4) DHW @ 45C is quite low. Suggest you increase it to 48-50C, and from that increase the peak setting to initially 14 days or as we have here 30 days @48C. With high usage, you are very unlikely to get a bacterial infection in the dhw tank, but as always it is up to you to decide.

These are suggestions above and it is entirely up to you to decide on which way you want to move the parameters of the system.

encap

Hi lovesgshp,

I hope you can help me with my problem. We recently moved in to a house with gshp. There is ufh with 6 radiators upstairs. The pump is really high on electricity and we would like to cut the costs. It was set for going on only during night time between 00:00 and 8am to take advantage of cheaper tariff.

Last week I was happy with the indoor temp and decided to change the time heat pump goes on. I reduced that to only 3hrs but I am not sure if I changed the right thing. What I changed was Clock setting HP accord. to clock.(4.1) I then checked the Setting level heat pump +/- (4.1.1) and it is set to -6 degrees, I didn't touch that one, but I think that's too much, manual says up to 3 degrees is ok.

After a day or so the house was little bit colder and the radiators upstairs are cold, so now I changed that back to the previous settings, waiting to see the results, but my question is what I actually changed? Is it the time when the heat pump goes off or the time when the heat pump produce less heat(-6 in this case)? I'm constantly monitoring my electricity meter and I don't see much difference between these two settings. The installer told me the pump will go on only during the night cheaper tariff for 8hrs, did he mean the additional heat will go on or the pump itself?

I know you probably need some more details regarding the pump, I will update that later on, but I'm interested what I changed? Thanks in advance