my GSHP installation + experiences since

[zippy7272]

 

If you have any questions - I'll try to help!

We live in an area that doesn't have mains gas.  When we bought the house (June 2010) we'd already decided on changing the perfectly good oil boiler to a GSHP.  The GSHP was finally installed in Feb 2011 - we had an unexpected wait having to get our electricity supply upgraded to 3 Phase (We also bought a 10kw PV system at the same time - which made  the 3 phase cost more justifiable)

We bought a GSHP, and not an ASHP as we are concerned that an ASHP just wouldn't work when the temperatures down to minus numbers.  We're assured that the GSHP will!

We now have an Ice energy 17kw (IVT) GSHP with approx 1km of underground pipes.  The purchase, delivery and ultimately the commission was painless.  We have a buffer tank, and a separate hot water tank.  So we now have the house at a constant 23 (ish) degrees (we like it warm!) and a permanent 42 degrees supply of hot water.

Since Feb 2011 we've only had a few days of frost (no snow) so I'm perhaps speaking too soon - but it has not given us a problem yet (nor would you expect one in the first 9 months) (We have 10yrs warranty on the GSHP.......just in case).

We had a wide variety of quotes for the installation (not the GSHP, buffer, hot water tank, or underground pipework and manifold)  from £33k down to £8k...As you can see a HUGE variation.  I won't name the installer (as there's probably rules about doing that) but they were the cheapest and they certainly did a FANTASTIC job.

We don't have have underfloor heating, just regular radiators, the building is over 150yrs old.  Though some of the walls have been rebuilt with cavity insulted walls + the loft has a foot or so - of blown wool (it's not big enough to roll insulation in).  And it has double glazed windows.

If your considering a GSHP and certainly if you're moving away from Oil I'd defiantly recommend it.  I estimated we would have spent around £2k a year on oil alone.....now our electricity bill (heating, electric and hot water) is just under £70 pm.  I know the PV have reduced the electric consumption a little.

NB we're also on economy 7 - as I guess it'll be coldest between 1am and 8am most days when the heating needed the most.

Oh - we're a regular family with 2 kids - 10yrs and 12yrs in a good (dare I say it large) 5 bedroom house.

Just my experiences, and as I say happy to help if anyone has any questions / thoughts.

[mpooley]

Thanks very much for that, it's nice to see how other people are getting on with the GSHP as we are thinking very seriously of having it fitted ourselves.
I Hope you let us know how it works this winter.

I am particularly interested in your " cavity insulted walls " as this sounds very cheap!
did you have to think of really good insults or did you just swear at it?

LOL     sorry I couldn't resist that one.

Mike

 

[JonG]

Hi Zippy 1 thing to think about, Ice generally use slinkys, I am guessing they will have in your installation. There are concerns in the industry about the potential for them to extract too much heat from too small an area of earth.

This generally manifests itself slowly over time (years sometimes), but in order to give yourself  a heads up of a possible issue, record the temperature of the incoming glycol annually during the depths of winter. If the temp is dropping year on year the earth is not recovering sufficiently over the summer.

The data is available from the Rego under the "Monitor All Temperatures" section.

Cheers

J

[titan]

Ice generally use slinkys, I am guessing they will have in your installation. There are concerns in the industry about the potential for them to extract too much heat from too small an area of earth.

Any type of ground array has the potential to do the same if it is undersized. The only cases where  I have read about problems with slinkies are where they were undersized, Slinkies have been in use around the world for many years if there was a generic problem it would be very public by now. I would be interested to know who are these industry people who have these concerns, obviously not the ones that use slinkies.

[zippy7272]

Hi Zippy 1 thing to think about, Ice generally use slinkys, I am guessing they will have in your installation. There are concerns in the industry about the potential for them to extract too much heat from too small an area of earth.

This generally manifests itself slowly over time (years sometimes), but in order to give yourself  a heads up of a possible issue, record the temperature of the incoming glycol annually during the depths of winter. If the temp is dropping year on year the earth is not recovering sufficiently over the summer.

The data is available from the Rego under the "Monitor All Temperatures" section.

Cheers

J

My installer insisted on a non-slinky installation, so as we have the extra land, it wasn't a problem for us to agree.  Our installation uses 1km (200m x 5) of pipes + 50m

@Mike - my walls' mother used to be in a treatment works - so the insults were pretty easy - LOL! 

Temperatures so far have been fine in the house, OK so I don't think it's been much below 0 too often outside so far.  So far so good, a nice steady 23.