Moving to heat pump?

irewestlad

hey all

I’ve long considered I want to move from oil boiler to heat pump.

For background, I have a large solar array installed with eddi, a 5kWh battery and I also have 2 Nests in the house

If I move to a heat pump I guess the Nests are redundant? I thought about buying a larger battery and running the heat pump from that after night rate charging - is this practical?

Any recommendations for installations in Galway? I also need to get an assessment complete on the house to understand if it’s heat pump ready - again any recommendations for who I could use?

Thanks folks

Biker1

The PV will not run a heat pump unless it is tiny which I assume it would not be in an average house. You will find a list of technical assessors on the SEAI website. What part of Galway are you in?

THE ALM

In a similar boat to yourself and have been doing the homework on changing over from oil also.

Have a good solar set up with 9.6kWh battery and will be looking to charge at the EV rate to offset during the day. Have Eddi also but I would think we would be ditching this as heating with the heat pump would be a more efficient way of doing it.

Looking at bills we are also hoping to have a good credit built up that would cover a large proportion of the heating costs during the winter. We have been going into credit since April and should see this continue into October I would think.

You could PM me as I carry out Assessments in your area if that suits.

We have done a few upgrades to the house and the heating is the final change to be done before making the change.

graememk

As a very rough benchmark on running costs

How much oil do you currently use? Each litre of oil has roughly 10kWh of heat, and depending on how old your oil boiler is, you could be getting 60[old]-95%[new/condensing] of that heat out of it.

PV won't cover the hp use in the winter, batteries could, by charging on night rate, but you'd need roughly 3-4x your storage capacity

kabakuyu

https://www.boards.ie/discussion/2058359157/moving-to-heat-pump

What's your current level of insulation and air tightness?

darraghsherwin

I am in the same boat, my oil boiler needs replacing soon and I am debating whether to go HP or replace it with a more efficient boiler.

how many kWh does a HP require during an average winters day for a 180sqm detached house?

Currently have 20kWh of battery capacity but could add another 20kWh but not sure if I could charge up that much batteries in any existing EV tariff without moving to 3phase

graememk

https://www.boards.ie/discussion/comment/122366911#Comment_122366911

How much oil do you use normally in a season?

150m2 roughly

1980 bungalow, decent attic insulation. Using radiators already in the house, upgraded one in the living room, (2 external walls, and big windows.. and a stove)

https://emoncms.org/app/view?name=EcoAir&readkey=82a75750e2f56ccdc7e96768b9776268&mode=daily&start=1701561600&end=1720742400

Dr.Tom

https://www.boards.ie/discussion/comment/122366938#Comment_122366938

Hello. Just for clarity what are you calling decent attic insulation?

External insulation or cavities full filled?

graememk

https://www.boards.ie/discussion/comment/122367046#Comment_122367046

about a foot of rock wool, on top of what was there when the house was built, Made a huge difference to the house.

No external insulation, Just the standard cavity with about an inch of aeroboard in it.

Mr Q

I run my HP from the house battery over winter, the battery is about 30kWh.

Even in the coldest day over the winter there would be no issue for me. The house is 210sqm.

But I am on a 9 hour night rate so easy to charge it back up fully over night.

randombar

I did just this last year.

Was spending about 1000 on oil per year.

I did retrofit ufh as part of this work (circa 15k including laminate everywhere), milled the ufh into the floor as I had enough insulation underneath.

The UFH is class.

Insurance went down also as I got rid of the Kerosene

Great to get rid of another bill.

Cleaner, don't have to worry about oil levels etc.

20kwh of batteries, 4hrs of cheap rate with energia.

What I need to get used to is to stop looking at the meter on the cold days. I never looked at the oil tank in the same way and I need to get used to it balancing out.

Dr.Tom

https://www.boards.ie/discussion/comment/122368017#Comment_122368017

What's your return on investment for this?

Did you do much sums before pulling the plug on the Heat Pump and retrofit?

randombar

https://www.boards.ie/discussion/comment/122368038#Comment_122368038

I'm an unusual case as I'd a fire in the garage wipe out the boiler.

I'd prefer not to think about the roi to be honest 😂 but you can't really measure roi on the comfort of ufh.

maybe 20k for ufh, new floors and heat pump thanks to some favourable grants (door and window replacement because of fire etc.)

darraghsherwin

probably should have clarified, house built in 2008.

There was 50mm of insulation in the cavity walls but have had them pumped last year with an extra 50mm

Attic insulation upgraded to 400mm

Currently using about 1100 -1200 litres of oil a year

S'

https://www.boards.ie/discussion/comment/122369354#Comment_122369354

Did you notice much improvement in heat loss pumping the cavity?

Was it beads you used?

irewestlad

thanks all, great info in the replies. I’m guessing the first thing I need to do is an assessment of the house to see how heat pump ready it is. Any recommendations for someone in south Galway region?

Dr.Tom

Theres 70s and 80s bungalows (even some Rofab) in my area with spanking new heat pumps perched outside them. I hope they all have supporting works done to assist the heat pump but I doubt it in some cases

Calahonda52

https://www.boards.ie/discussion/2058359157/moving-to-heat-pump

Starting point is to get a BER done on existing and see where the heat loss indicator HLI is at.

Needs to be at least 2-2.3 for the grant but HP works much better the lower the HLI

On pricing: HLI could be 4.5 and it might cost 80k to get to 1.5

PV gives a BER rating uplift but does not help the HLI

darraghsherwin

https://www.boards.ie/discussion/comment/122372188#Comment_122372188

Sorry, I didn't reply sooner, was away on holidays.

Our HLI went from 1.879 W/m2k to 1.755 on external walls according to the BER. (I am not sure I believe this as I think the original HLI is based on an average and not actually measured for the property)

Subjectively, I think it did make a difference. The house seems to be warmer for longer but we control our heating thermostatically with a Hive, so it's always set to 19.5c so the boiler might only kick in for a few minutes. I think our oil bill has decreased.

We used beads from a local crowd here in Sligo

micks_address

Hi folks - not wanting to start a new thread. I'd a question on heat pump placement. Can they be placed outside a kitchen window at the back of the house? We are in a semi d and the side passage is narrow and I've heard they arent the best place for them anyway as you can get cold microclimates down the side of the house where the sun never shines etc..

Nothing happening any time soon but just plotting for the future

Cheers,

Mick

Mr Q

https://www.boards.ie/discussion/comment/122419210#Comment_122419210

Mine is at the back of the house, between the back door and office window.

No issue with where it is for me.