Air to Water Heat Pump

swededmonkey

We've recently gone sale agreed on an older property and looking at replacing the heating system. Given the focus on sustainable energy and carbon emissions we're considering an air to water heat pump. Has anyone any experience with this and can give an idea of cost? SEAI are offering grants up to €3500

_Brian

The key with this type of technology is the detailing on the house.

I’d worry with an older property that the airtightness and insulation properties will be insufficient to let the heat pump do the job.

If your looking at an overall upgrade then it’s worth considering.

swededmonkey

First jobs being done are cavity wall and attic insulations. They're both pretty much non existent at the minute. Would you reckon that would be sufficient to get the benefit for what we're proposing?

MicktheMan

No, more than likely not.

_Brian

No I don’t.
The heat pump technology relies on super detailing and I’d worry without a deep retrofit you won’t have enough heat and be having mad esb bills.

That’s the most common complaint I see, poor heat retention causing the pump to run constantly, the house is cold but the bills are monstrous.

Sleeper12

My own home was built in 1964. I have it well insulated with 100mm foam boards and attic insulation. I'm a plumber myself but specialise in showers. I'm not up to date with the latest heating. I asked on a plumbing group that I'm a member of. Every plumber that replied said that my home isn't suitable for heat pump. All of the ground floor flooring would need to come up & underneath insulated. The house will need to be made airtight. Every one of the plumbers said its not worth my while.

Another thread I read here but can't find now had a poster with a heat pump. He did the calculations & it's costing his 450 euros per year just to have his system on standby. He can't turn it off because even in the summer he needs to for hot water. They are not all that expensive to run but worth thinking about

Toyotafanboi

We bought a 1960's bungalow last year and are going with an air to water heat pump. The renovations aren't fully complete yet so I cant comment on the running costs but we're hoping for the best.

The house had 9" cavity block walls, suspended timber floors.

We did hire a BER advisor for his thoughts on the matter.

We've structurally removed the existing chimneys, went with 100-120mm (where practical) external insulation, 300mm earthwool in the attic and 150mm earthwool under the floors on his advice. All window and door jambs are being taped before re plastering, the floors will have a membrane, taped at the edges, all light and electrical fittings taped, tape galore, really.

The proposed HLI after the retrofit works is 2.24 w/km2, which is apparently more than the advisable 2.0 or less for a heat pump to be viable but were going to take a chance on it, first fix is already in for it so no going back now. Could be eating my words.

Alf Veedersane

Toyotafanboi wrote: »

We bought a 1960's bungalow last year and are going with an air to water heat pump. The renovations aren't fully complete yet so I cant comment on the running costs but we're hoping for the best.

The house had 9" cavity block walls, suspended timber floors.

We did hire a BER advisor for his thoughts on the matter.

We've structurally removed the existing chimneys, went with 100-120mm (where practical) external insulation, 300mm earthwool in the attic and 150mm earthwool under the floors on his advice. All window and door jambs are being taped before re plastering, the floors will have a membrane, taped at the edges, all light and electrical fittings taped, tape galore, really.

The proposed HLI after the retrofit works is 2.24 w/km2, which is apparently more than the advisable 2.0 or less for a heat pump to be viable but were going to take a chance on it, first fix is already in for it so no going back now. Could be eating my words.

Is it a bungalow?

swededmonkey

swededmonkey wrote: »

First jobs being done are cavity wall and attic insulations. They're both pretty much non existent at the minute. Would you reckon that would be sufficient to get the benefit for what we're proposing?

I know my parents looked into it with their 1980’s built house and the outcome was sticking to oil would be cheaper than all the upgrades required before even installing the heat pump and has they have a limited lifespan it would not pay for itself compared to sticking with oil.

If building a new house (which I am) it’s still debatable if going with rads but if going for underfloor then the heat pump is the better option. I haven’t got to the stage of deciding yet but it won’t be a “no brainer” going for the heat pump there will be a decision to be made.

Qrt

A deep retrofit (ie to at least A level) is basically needed for a heat pump to work right. RTÉ got Duncan Stewart to do one of those programmes on it, a couple in Templeogue deep-retrofitted their house (those monstrously large ones of the 50s/60s).

michealkc

_Brian wrote: »

The key with this type of technology is the detailing on the house.

I’d worry with an older property that the airtightness and insulation properties will be insufficient to let the heat pump do the job.

If your looking at an overall upgrade then it’s worth considering.

How does the system work?

Would a 12 year old house built to 2006 regs be viable? C1 Ber rated. 2000 square foot

mcbert

michealkc wrote: »

How does the system work?

Would a 12 year old house built to 2006 regs be viable? C1 Ber rated. 2000 square foot

I've another thread going in Construction & Planning trying to work out and cost what is neede for something similar. If anyone has any more feedback on any of it, I'd love to hear it...

Alf Veedersane

michealkc wrote: »

How does the system work?

Would a 12 year old house built to 2006 regs be viable? C1 Ber rated. 2000 square foot

From what I can tell, the threshold for the heat loss indicator is based on a standard C1/C2 built to regs of their time so possibly even to 2002 Regs.

It would still need a technical assessment to verify that it meets the heat loss requirements without any additional work but I suspect yours would meet it.

That said, any additional work to insulation and airtightness will mean better performance of the system.

Gumbo

michealkc wrote: »

How does the system work?

Would a 12 year old house built to 2006 regs be viable? C1 Ber rated. 2000 square foot

2006 regs had very very little emphasis on air tightness so my
Opinion is that A2W would still require significant upgrades to this property.