Air Source Heat Pumps

Arraswold

Hi,

I was wondering if anyone could offer advice on air source. I don't have the space etc for ground source so my plumber has suggested a air source. It is to be used in a single storey holiday cottage conversion which will have underfloor heating as well as plenty of insulation. The size of the building is approx 150 sq/m and we are situated in east yorkshire. Basically I wanted to know which are the best machines and roughly the correct size to be looking at??? Also wheather the pump will be sufficient in the winter months?? I know it's quite a broad spectrum but thought I'd try to do some research before my plumber tells me a load of rubbish!?!

[Deleted User]

UFH is ideal for ASHPs but you need to do heat loss calcs in order to size the pump.

Sugest inviting round as many installers as you can find and take them up on visiting reference sites to speak to people who have them. Read as much as you can then work out if it will suit your requirements.

Properly installed/Spec'd ASHP work fine in winter. Last Dec with snow/ice our total electric bill for the house was £100ish, ASHP on 24/7. LPG the previous year with minimal use was 3-4 times that.

Ecokev

Just had a customer confirm his winter bill running 4 bed detached in middle of nowhere, est £90 a month for hot water and heat with his ashp

TiredGeek

Cardew wrote: »

I thought the system was going to be ripped out??

Please keep us updated on consumption through winter.

Yep, getting ripped out soon

We left it on frost 'stat at 10'c from early December '11 thru to early Jan '12, 33 days of mild weather (very unusual, it barely dropped near freezing).
In that time the system sucked up 3290 units, or £428 at current rates!
For 10'c. :mad:
Clearly this system is not suited to our property / micro climate, and so it's coming out.
Houses around us don't use anywhere near that in oil, and they're occupied and heated to 20' or more.

It's been a costly experiment, but **** this line deleted for legal reasons **** so we're only a few grand out of pocket.
At least we can still use the rads and most of the pipework for an oil system

Cardew

TiredGeek wrote: »

Yep, getting ripped out soon

We left it on frost 'stat at 10'c from early December '11 thru to early Jan '12, 33 days of mild weather (very unusual, it barely dropped near freezing).
In that time the system sucked up 3290 units, or £428 at current rates!
For 10'c. :mad:
Clearly this system is not suited to our property / micro climate, and so it's coming out.
Houses around us don't use anywhere near that in oil, and they're occupied and heated to 20' or more.

It's been a costly experiment, but **** this line deleted for legal reasons **** so we're only a few grand out of pocket.
At least we can still use the rads and most of the pipework for an oil system

It appears some people are lucky - and some are not!

I would never invest in a heating system where you take 'pot luck' if you are going to get a decent system or a disaster - and there are too many 'disasters' documented on MSE and all over the web.

The other aspect is that people are 'investing' £10,000 plus on an ASHP. That invested in a long term bank account will produce about £350 after tax - which will go along way to offsetting oil or storage heating running costs.

bernithebiker

I'm happy enough with our ASHPs. You MUST choose a good installer who knows his stuff, otherwise you are doomed to failure, no matter how good the machine you use.

zeupater

Arraswold wrote: »

Hi,

I was wondering if anyone could offer advice on air source. I don't have the space etc for ground source so my plumber has suggested a air source. It is to be used in a single storey holiday cottage conversion which will have underfloor heating as well as plenty of insulation. The size of the building is approx 150 sq/m and we are situated in east yorkshire. Basically I wanted to know which are the best machines and roughly the correct size to be looking at??? Also wheather the pump will be sufficient in the winter months?? I know it's quite a broad spectrum but thought I'd try to do some research before my plumber tells me a load of rubbish!?!

Hi

Regarding - "I don't have the space etc for ground source" ... have you considered vertical (bore-hole) ground heat exchangers ?

HTH
Z

lovesgshp

zeupater wrote: »

Hi

Regarding - "I don't have the space etc for ground source" ... have you considered vertical (bore-hole) ground heat exchangers ?

HTH
Z

Alternative and cheaper option to a borehole for small gardens. Copy & Paste into browser to view.

doc.ivt.se/download.asp?pt=pdf&fn=Brochure_News_Eng.pdf

zeupater

Geotherm wrote: »

Alternative and cheaper option to a borehole for small gardens. Copy & Paste into browser to view.

doc.ivt.se/download.asp?pt=pdf&fn=Brochure_News_Eng.pdf

Hi G

I've seen similar heat exchangers from other suppliers (Worcester Bosch ?), but have been told that they work best if penetrating the water table and take advantage of any downslope water migration and that if this isn't the case the units are so compact that they cool the immediate area around them too much and reduce the GSHP efficiency ... it made sense when it was explained to me and the guy seemed to be knowledgeable and sincere .... do you have an idea of whether this is the case ?

Z

lovesgshp

zeupater wrote: »

Hi

I've seen similar heat exchangers from other suppliers (Worcester Bosch ?), but have been told that they work best if penetrating the water table and take advantage of any downslope water migration and that if this isn't the case the units are so compact that they cool the immediate area around them too much and reduce the GSHP efficiency ... it made sense when it was explained to me and the guy seemed to be knowledgeable and sincere .... do you have an idea of whether this is the case ?

Z

All the WB heat pumps are IVT units, just rebadged, so they also use their compact collectors. Recharge is by a VBX heat recovery unit. We have a few of these installations here with no reported problems.
No need to penetrate the water table, but like conventional loops, damp soil is always better.

http://www.ivt.ee/pdf/Brochure_VBX_Eng.pdf