Ground Source Heat Pumps
Comments
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Hi,
Have to say I had a quick look at study paper you provided, the point trying to be put over is the fact GSHP through time can deplete thermal energy at a rate where mother nature cannot replace.
I suppose common sense will say compact systems at approx 1.5 metre below ground will stand a better chance to replenish due to being closer to thermal charge source? One main point that appears to have a MAJOR impact on these systems, is overall competence when a property is being surveyed for what it requires.
Test rigs arrived today, will give me a better understanding of equipment used, then better grasp of the over all technology...........hopefully :think:
:beer:0 -
When I posted originally, arguing about heat loss, I was referring to a horizontal system, as that is virtually unchanged. I put the above pdf link as additional from our research and in consideration of the earlier data link, as we know there has to be a recharge, due to the system heat replenishment constraints.Hi,
Have to say I had a quick look at study paper you provided, the point trying to be put over is the fact GSHP through time can deplete thermal energy at a rate where mother nature cannot replace.
I suppose common sense will say compact systems at approx 1.5 metre below ground will stand a better chance to replenish due to being closer to thermal charge source? One main point that appears to have a MAJOR impact on these systems, is overall competence when a property is being surveyed for what it requires.
Test rigs arrived today, will give me a better understanding of equipment used, then better grasp of the over all technology...........hopefully :think:
:beer:As Manuel says in Fawlty Towers: " I Know Nothing"0 -
Have been running some actual scenario tests over the last week and will post the results at the weekend, as have to let the unit stabilise from the last changes ( min 24hrs ).
1) Heat pump working in normal mode for DHW/Heating
2) Internal house log burner working ( no connection to either DHW/Heating ) with pump as in 1
3) Increasing internal temperature by 1C to 20C. (pump usage only ).
Average temps at the time (9.30 a.m. circa 1.5C) with 4 inches of snow on the ground. Internal temp sensor @ 70% influence over external unit. Underloor heating, no buffer tank.As Manuel says in Fawlty Towers: " I Know Nothing"0 -
Results from the above running tests:
1) With the pump running normally @19C for inhouse temp: Ground loop temp in 6.0C out 3.5 (delta 2.5C ) Operating hours 10 - 11 per day x 2.1Kw base = 21/23Kw + approx 2Kw for circulating pumps.
2) With the internal fire and no change in the above settings: House temp increased to 21C and heatpump running hours reduced to 8. Ground loop temperatures rose by over 2C input, showing the recharge was working even with a 2-3 hr reduction in operating times. Cost offset has to be considered here, as we pay circa Euro 12 per 100Kg of wood, so over the few days we probably burnt 30 KG min.
3) Increasing the temp to20C showed a significant change in running times. The first day after the increase, the pump ran for 17hrs, 2nd day 14hrs and has now stabilised @ circa 12 hrs. Ground loop inflow has reduced to 3.5C in/ 1.1 out. Heating delta on the heat transfer system has stayed at a 6.5C in all the above situations.As Manuel says in Fawlty Towers: " I Know Nothing"0 -
Wow your timing is somewhat perfect!
We have just had our first bill after fitting our GSHP two months ago and i am somewhat shocked at how high it is!
Will give as much spec here as I can
Fitted a Ground Source Heat Pump Greenline HT + E11 (Single Phase, Soft Start) (supplier: Ice Energy)
House is chalet bungalow with basement. All UFH and super insulated.
Floor area being heated is somewhere in region of 350m2.
We have a ground loop in the garden and a friend fitted same system but their bills are significantly less!
Been living in house for 2 months now. First bill based on actual reading is £590.
We are 2 adults (though had guests over xmas) and have 2 single ovens, an induction hob (which apparently draws a lot of power!) TVs, washing machine (not been using tumble dryer!).
Am hoping something is set up wrong and future bills wont be £300 per month!
All room stats are set to about 20 or 21 degrees. SOme of the UFH was accidentally set to ON permanently rather than coming on and off during course of day.
Our Elec supplier is E-On. Tariff is
Normal units up to 900 kWhs per year
18.858 pence
Normal units
8.589 pence per kWh
Hope this all makes sense! Why on earth are our bills so high? I know the house is big.. but really????
The GSHP engineer said the Pump was drawing the same power as 2 kettles....!!!!!!???0 -
Wow your timing is somewhat perfect!
We have just had our first bill after fitting our GSHP two months ago and i am somewhat shocked at how high it is!
Will give as much spec here as I can
Fitted a Ground Source Heat Pump Greenline HT + E11 (Single Phase, Soft Start) (supplier: Ice Energy)
House is chalet bungalow with basement. All UFH and super insulated.
Floor area being heated is somewhere in region of 350m2.
We have a ground loop in the garden and a friend fitted same system but their bills are significantly less!
Been living in house for 2 months now. First bill based on actual reading is £590.
We are 2 adults (though had guests over xmas) and have 2 single ovens, an induction hob (which apparently draws a lot of power!) TVs, washing machine (not been using tumble dryer!).
Am hoping something is set up wrong and future bills wont be £300 per month!
All room stats are set to about 20 or 21 degrees. SOme of the UFH was accidentally set to ON permanently rather than coming on and off during course of day.
Our Elec supplier is E-On. Tariff is
Normal units up to 900 kWhs per year
18.858 pence
Normal units
8.589 pence per kWh
Hope this all makes sense! Why on earth are our bills so high? I know the house is big.. but really????
The GSHP engineer said the Pump was drawing the same power as 2 kettles....!!!!!!???
With that EON tariff you have used about 7,000kWh in 2 months.
Let us assume that you have used 1,000kWh in non-heating applications, that is approx 6,000kWh in 2 months for heating and hot water.
If your system has achieved an overall COP of 2.0 that is 12,000kWh
The temperature of the water in the UFH and particularly the DHW has a large influence on the efficiency and how often the immersion heater kicks in.
It has been an extremely cold 2 months and yours is a large house. If the engineer said it was drawing the same power as 2 kettles that is 6kW.
Personally I would have been surprised if a 6kW system(if that is what he means) would cope in such a large house.
Anyway Geotherm has a lot more knowledge on GSHPs and no doubt he will comment.
P.S.
If it is any consolation whilst induction hobs can draw lots of power, they are far more efficient than 'normal' radiant hobs and use less power.0 -
Nosha123.Wow your timing is somewhat perfect!
We have just had our first bill after fitting our GSHP two months ago and i am somewhat shocked at how high it is!
Will give as much spec here as I can
Fitted a Ground Source Heat Pump Greenline HT + E11 (Single Phase, Soft Start) (supplier: Ice Energy)
House is chalet bungalow with basement. All UFH and super insulated.
Floor area being heated is somewhere in region of 350m2.
We have a ground loop in the garden and a friend fitted same system but their bills are significantly less!
Been living in house for 2 months now. First bill based on actual reading is £590.
We are 2 adults (though had guests over xmas) and have 2 single ovens, an induction hob (which apparently draws a lot of power!) TVs, washing machine (not been using tumble dryer!).
Am hoping something is set up wrong and future bills wont be £300 per month!
All room stats are set to about 20 or 21 degrees. SOme of the UFH was accidentally set to ON permanently rather than coming on and off during course of day.
Our Elec supplier is E-On. Tariff is
Normal units up to 900 kWhs per year
18.858 pence
Normal units
8.589 pence per kWh
Hope this all makes sense! Why on earth are our bills so high? I know the house is big.. but really????
The GSHP engineer said the Pump was drawing the same power as 2 kettles....!!!!!!???
Can you please take a number of readings for me from the 2nd customer screen (K2).
I need all within menu 1
All readings from menu 3 after pump has been running on heating cycle for approx 10 - 15mins
Readings from menu 7
Details of recent alarms from menu 11
Thanks
Have you 70% of the underfloor heating open?As Manuel says in Fawlty Towers: " I Know Nothing"0 -
Thanks Chaps.. and thanks Geotherm.
I will have to come back to you with the readings... give me a day or two to get this sorted (am not at home right now!!).
Really appreciate your help on this too!!0 -
Also surprises me Cardew, that the engineer is saying that the unit is using the power of 2 kettles. At 0/35C, the power consumption is 2.2 kw on that model, rising to 3.0 with a 50C temp output, plus circulating pumps. The electric backup heater should not be cutting in under normal operating conditions and this is why I have asked for menu7 readings, as these show normal operation plus electrical immersion input.
With the same model here, I only use around 10k Kw per year in total for the house and all appliances (3kw oven, washing machine, tumble dryer, dishwasher, 2 fridge/freezers etc ).
I need to look at the running figures and temperature deltas to start with and then go from there with other settings.As Manuel says in Fawlty Towers: " I Know Nothing"0 -
I think it is unlikely nosha123 is able to heat 350m2 in the weather conditions we have had in the last 2 months with the heat pump alone.
A rough optimistic guide at 50w/m2 would suggest 17.5 kw is needed.
2.2kw input: what is the output at 0/35C ?
If it was a 6kw input (2 x 3kw kettles) and 18kw output then that would be more realistic.0
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