ground source heat pumps

[foxbox]

May i ask what sort of electric bill do you get of do you have solar aswell?

We're feeding it in part from a solar array however this was only budgeted to supply around 25% of the power required. Difficult to be sure what % is actually supplied by it as it is also supplying the fans on the grainstore and the other farm buildings too and we haven't got clever enough metering to take all of this in to account.

Simplistic version of the economics behind it though; the install cost roughly twice as much as a conservative projected cost of the oil and boiler maintenance for the next 20 years. RHI and associated savings/income will return 1.5x the investment. So even if the system massively under-performs and the RHI only repays the investment (and we end up with a 0 balance) we're still considerably better off than if we'd just burnt oil for the fun of it for 20 years. And yes; these figures did factor in cost of financing, interest, tax implications etc as best we can too. So far we're achieving what was projected and we're therefore happy . I've no intention of discussing the economics of it further than this but the point remains; technically heating water to 55C with GSHP's can and does work and financially (vs oil and LPG) it pays too.

 

[Mur Huwcun]

How’s everyone’s GSHP system coping with recent weather? We had a power cut for 24hrs which did not help things but I cheated and used some add in heat to get back up and running.

Our brine temp in the loops has dropped significantly in the last week, we’re now on around 0 degree incoming and going out at around -4. It’s not been this low before but seems to cope. Interesting to compare with soneone else’s data.

 

[Grassman]

How’s everyone’s GSHP system coping with recent weather? We had a power cut for 24hrs which did not help things but I cheated and used some add in heat to get back up and running.

Our brine temp in the loops has dropped significantly in the last week, we’re now on around 0 degree incoming and going out at around -4. It’s not been this low before but seems to cope. Interesting to compare with soneone else’s data.

I will look later. Ours has been excellent. Only put the log burner on for a couple hours on 2 days. The mrs moaned it was too hot when the living room got to 27 degrees!!
The windows had to be opened for a bit and let the log burner go out.

 

[e3120]

I will look later. Ours has been excellent. Only put the log burner on for a couple hours on 2 days. The mrs moaned it was too hot when the living room got to 27 degrees!!
The windows had to be opened for a bit and let the log burner go out.

Are you on rads or underfloor? Modern with decent level of insulation? Like the idea of GSHP, but barely warm enough here with rads at 75 degrees this week.

 

[Grassman]

Are you on rads or underfloor? Modern with decent level of insulation? Like the idea of GSHP, but barely warm enough here with rads at 75 degrees this week.

I knocked the old crappy farmhouse down. Built a new 3 bed bungalow. Underfloor heating and insulated to modern standards.

 

[suffolksmallholder]

How’s everyone’s GSHP system coping with recent weather? We had a power cut for 24hrs which did not help things but I cheated and used some add in heat to get back up and running.

Our brine temp in the loops has dropped significantly in the last week, we’re now on around 0 degree incoming and going out at around -4. It’s not been this low before but seems to cope. Interesting to compare with soneone else’s data.

We fitted a GSHP in a small dwelling in 2009. Two trenches totalling 160 metres in length 1.0 meter deep & 1 metre wide. I always thought it ran out of umph about this time of year when the ground was coldest. It then relied heavily on the immersion. If there was space & there wasn't any, I'd have liked to have fitted a small boiler for just this time of year. Otherwise the machine performed well. Mitsubishi pump & the tenants were happy.
In the past we had two ASHP's fitted in 1983 & 1987 respectively. Made in Manchester by a British co. Superb but they were both coulpled to oil boilers for the same yearly reason. It's too long ago to provide any calc's on these but I simply remember they saved considerable £'s each year until they needed servicing which took out any gains! Being pre-micro-chip the interior workings resembled a telephone exchange!
Both ran until the late 90's when the properties were sold to London commuters who just used the oil CH boilers. The ASHP was likned to grant aid & the two earlier were simply a money saving excersise which over time they were.
SS

 

[Mur Huwcun]

Ours has had a proper test this year, we’ve had much colder weather and more than enough of this eastern wind. Our utility room which contain the HP and plumbings etc (stone build cow shed or similar that’s been incorporated into the house) faces East and therefore gets all the wind. This room always feels colder when the wind is from this direction. We’ve not yet quite finished the renovations and the log burner has not been fitted therefore the GSHP and underfloor have been heating the whole house. Next winter should be easier on the system.

Just had a look at pump now and brine in is 0.8 degree now and out is up to -3.5. The only negative to the whole system is it’s taken since 5 o clock on Friday (when power came back on) for the house to come back up to temp. It’s 19 degree inside now. I have the imersion set to off so that we wont have a surprise electric bill but used 4kw of it on Friday night to start things off

 

[Biomass Bart]

Interesting that no one talks about cooling with GSHP - it can be used for example for cooling milk, saving on average £15/cow/year, and recuperated heat can be used for heating sheds or houses. Same goes for Cold Storage, for example for potatoes, again heat pump can be used to remove heat from the storage, saving up to 50% of cooling cost.
The heat removed from cold storage or milk can be then used to generate income from RHI, lowering the cost of running GSHP.
Good GSHP will have SCOP of 5 when running at 30C, when running at 55C it will be 3. And they can be fitted with superchargers, to provide water temperatures up to 70C.
All benefits of biomass but with far less hassle and maintenance.
If anyone is interested in finding out more please PM me. Dunster.biz 07961 490 667

 

[Turra farmer]

It

Can anyone explain how GSHP is worth the extra cost over ASHP . Just curious.

It's not

 

[Vader]

It


It's not

until you get a cold winter and air source don't work.

 

[Turra farmer]

until you get a cold winter and air source don't work.

They work down to -22 degrees c

 

[f0ster]

yes but at that temp the cop is very poor

 

[Biomass Bart]

It


It's not

I disagree...
Water/Ground-source heat pumps Ground-source heat pumps & Water-source heat pumps All capacities Tier 1 9.36
All capacities Tier 2 2.79
Air-source heat pumps (commissioned on or after 4 December 2013) Air-source heat pumps All capacities 2.69

Almost 4 time the payback - ofcourse we are talking about commercial size. And they can go up to 1.5MW

 

[akaPABLO01]

yes but at that temp the cop is very poor

But over a year it’s balanced

 

[Courier]

until you get a cold winter and air source don't work.

Well our ASHP worked without a hiccup last winter which was supposed to be one of the coldest recently - biggest problem in when the weather warms up und the 7” thick concrete floor (laid in 1995) is holding too much low grade heat