ASHP replacing bottled LPG or should I go for oil?

buglawton

Geotherm wrote: »

We are talking about ASHP sytems, not GSHP which requires land.
With GSHP you can actually use compact collectors which only need circa 40 sq mtrs of land.

Useful to know.

Does my comment that "Perhaps the best thing is to get an independent, financially disinterested energy systems surveyor in first" still stand?

lovesgshp

buglawton wrote: »

Useful to know.

Does my comment that "Perhaps the best thing is to get an independent, financially disinterested energy systems surveyor in first" still stand?

Yes, why not. A good thermal engineer should give a report on heat /loss requirements for every room etc. Normal reports here, go to minimum 6 pages.
The way we work here in Italy ..... we send a basic questionnaire and from that we give an estimated cost, but we ask that the client gets the above report, or we will caculate if we have the full house details, as we have thermal engineers as well.
Example: Info given by client, our initial estimate 17KW requirement. Actual after thermal calculation 24Kw, by their architect. Installed 2x11kw GSHP on a radiator system ......... 10% reduction on loading for best system performance.

Cardew

TiredGeek wrote: »

If I were doing it again I'd try to get a cast iron money back if it doesn't work warranty before parting with any money.
...

The difficulty is determining if the system is working correctly. i.e. how many kWh has the ASHP used and how many kWh has it produced.

The other important consideration is the capital cost of an installation.

If the ASHP costs, say £4,000 more than a conventional central heating system, that sum invested long term at 4% produces £160 pa in interest(compounded) That is perhaps 25% of the average heating costs.

arty68

From the info so far in terms of money I would say oil is the best thing for you to go with and that comes from someone who is happy with his ASHP (I actually had very little choice as I couldn't have oil or bulk LPG anyway). Just don't buy your oil in the winter if you can get away with it..

TiredGeek

Cardew wrote: »

The difficulty is determining if the system is working correctly. i.e. how many kWh has the ASHP used and how many kWh has it produced.

Valid points, but I was actually thinking more of the thing actually getting through the winter without going wrong

Stuckupahill

Have you thought of running a heating system via a thermal store...
basically it's a large super insulated hot water tank which can take a variety of heating sources....boiler, solar, wood stove, immersion...it gives you a bit more choice .....

We were in a similar situation when we moved into our cottage two years ago....LPG was frighteningly expensive then...heaven knows what it must cost now.
We had a thermal store installed - fed via a solid fuel rayburn.
We';re saving up to install solar and woodstove in the system.
We also dug out the downstairs floor and put in underfloor heating, then replaced the flagstones. It means the floors are lovely and warm for our toddler (we kept the radiators upstairs).
We burn coal mainly plus whatever wood we can get hold of - it probably costs around £1000 a year in fuel...but the plan is to burn more wood than coal in future......
We're installing double glazing and trying to draught proof and insulate the walls this summer ready for next year.
We like the rayburn, but if I were doing it again I'd be tempted to install a more economical/efficient solid fuel boiler - I saw some which burn anthracite beans (German i think) and they were way cheaper to keep going than the rayburn - and alot cleaner!
I can't find it now but it looked similar to this - which burns wood and peat
http://www.mypublicface.com/uploads/frontier/Brochure_for_FKHO_Solid_Fuel_Boiler.pdf

Personally I'd steer clear of oil if you can help it, have you room for a ground source heat pump?

maelstrom

Thanks andygo999, Is what you are suggesting the same as replacing my open fire with a stove that has a backboiler?

Thanks

Stuckupahill

Not really.
Replacing your open fire with a stove and backboiler will give you a way of heating water.
But you need somewhere to put all that hot water you're creating. Usually it's pumped around a radiator circuit and also stored in a conventional hot water tank for domestic hot water (baths, taps etc).

A thermal store replaces the hot water tank. All the hot water goes into the store first and is then pumped around the radiator circuit (and/or underfloor heating). It'll also give you mains pressure hot water to the taps.

It's worth considering if you plan to include other types of heating sources in future. The advantage is that you can have a variety of heat sources all working on the same system - wood stove, solar panels, wind turbine, oil/lpg boiler - can all be used to heat water in the store. You're not reliant on one energy source.

The disadvantage is they are alot bigger than a traditional tank so they do take some heating up. And I don't think you can combine them with Air source or ground source heat pumps.

You need to work out what your main heating source will be and if you will be using other heating sources in future (and how long you plan to live in the house).
They are quite expensive to buy and install so unless you're going to include renewable heat sources at some point then maybe you're better off connecting your wood burning stove to a conventional hot water tank.
Thermal stores have their critics too so do some research if considering one.
For us one of the benefits is that it means we can use underfloor heating...which i really recommend.
We've got ours under the flagstones and it gives off a nice heat, means the floor is toasty for our kid (and cat!) and best of all is cheaper to run, because the water doesn't have to be heated as hot as running normal radiators.
Hope that helps
By the way if your cottage is anything like ours then draftproofing will make a huge difference to your heating bills too
Andy