Heat Pumps - post here.

redmagic68

https://www.boards.ie/discussion/comment/120552520#Comment_120552520

Been running a heat pump for 12 years with 3 breakdowns 2 caused by rodents and the third an installation issue fixed under warranty. The unit gets serviced every two years for €250 and that covered the two wiring issues from my furry friends. Otherwise the unit has been bullet proof.

not sure where your coming from with the post above but my running cost are less than they would be with oil, require no delivery and now with solar Pv I can produce my own fuel.

the house was designed around this type of heating systems so obviously it’s horses for courses but again the savings will easy accommodate the replacement cost in probably 8 years time which will likely be grant aided. I’m estimating that the difference in cost for replacing a heatpump with similar rated oil boiler would run to approximately 4k but open to correction there but looks to me like the savings will more than make up the replacement cost.

Tar.Aldarion

https://www.boards.ie/discussion/comment/120550603#Comment_120550603

Good to know that that is possible thanks. Mine seems to just have the ability to choose when the coil comes on. From what I've observed it just stays in heat pump mode, takes the same amount of time and electricity, which is very little. When the heating coil is on the energy usage is huge, I'd definitely know :D There is a symbol if it is on. Last night the total usage was 2.5Kwh for water heating or around 50 cent but that will vary.

I might turn it down to 60 or so and see how I get on gradually lowering it until I find a sweet spot that not all the water is used but nearly.

Snugbugrug28

Has anyone used their Heat Pump to provide cooling in summer? I'm pretty sure my Panasonic could do this per photo attached.

Wife likes to keep the little ones room cool and can really open windows due to plane noise

graememk

https://www.boards.ie/discussion/comment/120552936#Comment_120552936

Yes. But it's complicated heat geek explain it well

https://youtu.be/dn4Ja_q5M9g

Mr Q

https://www.boards.ie/discussion/comment/120552936#Comment_120552936

Yes, I do in the summer. Not a Panasonic but I have had no issues doing this with UFH.

Snugbugrug28

https://www.boards.ie/discussion/comment/120553945#Comment_120553945

How does this work? Do you need an Aircon unit or does it simply cool down the radiators?

Mr Q

https://www.boards.ie/discussion/comment/120554392#Comment_120554392

I just set it to cool on the control panel, NIBE unit.

Mine cools through the underfloor heating pipes and it works well for me.

Not sure how it would work with radiators but I have heard not very well before.

Snugbugrug28

https://www.boards.ie/discussion/comment/120554435#Comment_120554435

Thanks. I couldn't see it working well via the radiators myself tbh.

the_amazing_raisin

https://www.boards.ie/discussion/comment/120555587#Comment_120555587

You need something to circulate the cool air, convection unfortunately doesn't really work in reverse 😁

Maybe something like this would help, although preferably without the £76 price tag for what is basically a few computer fans 😕

https://www.amazon.co.uk/dp/B0968S45JJ?ref_=cm_sw_r_apann_dp_S65VE0K6PW0401T4HCZC

Another solution might be to just have a fan going in the room pointed down a bit to force the air around. If it's only for a few days in the summer then it's a simple enough option

When my current heating only one packs in or if I extend the house then I'll definitely be upgrading to one with cooling. I'll probably have to budget for replacing the upstairs rads with fan assisted ones, but personally I think it'd be worth it as the bedrooms can get unbearably hot in July and August

graememk

https://www.boards.ie/discussion/comment/120555923#Comment_120555923

Could be cheaper to just get some Aircon now, youll have the solar to run them!, Just need somewhere convenient to vent them out

JayBee66

Cooling? For an Irish summer? Unless Dublin has become a heat island, wanting to cool down is not a thing outside The Pale.

If I want to cool down in summer, I just wait 5 minutes for the inevitable clouds, rain and wind. Our house is well insulated from cold and heat. Even at the height of summer and the clouds abate for a few days, the indoor temperature might get to 23C but rarely does so.

sydthebeat

https://www.boards.ie/discussion/comment/120557201#Comment_120557201

Over heating is actually a big problem for some poorly designed new houses in Ireland, and as averages temps rise and building regulations tighten, it will be become more and more of a problem.

Of course, the issue should be able to be solved by design and passive measures, rather than high energy means

DC999

https://www.boards.ie/discussion/comment/120557235#Comment_120557235

Yep, in terms of house design we suffer. We've an old, small red brick house. Lovely to look at :) But the dark bricks absorb the sun all day and pumps it into the house at night. Bedroom stays in high 20s all night during sunny spells. So that's hard to sleep. Live beside a busy road that has traffic 24x7 so can't open the window. So I've to live with it. Even if I have the windows open before we go to bed, then temp quickly ramps up once the windows are closed. We couldn't get an Eddi for that reason as HWT is in our bedroom so would further cook us at night - don't use the HWT for showers, use an electric shower.

Aside from active cooling (like aircon), I'd have to get passive ways to cool it like thick creeper growing on the wall (which takes year to grow and then needs maintenance to stop if going into gutters, neighbour's wall... Or bit the bullet and get insulation externally or internally - passive way again. but large cost. I'd rather not get aircon as it's wasteful energy wise. Could get a ceiling fan either.

sydthebeat

https://www.boards.ie/discussion/comment/120558223#Comment_120558223

have you considered passive stack ventilation if you have a central stairwell??

i wouldn't go near a creeper on a brick dwelling, it would destroy your walls over time, even the most least disruptive will do some damage.

if going down that line, look at a trellis construction on the walls you want to shade, and use something like Japanese ivy, fast growing an pretty. it will need maintenance to keep it away from gutters etc though.

DC999

https://www.boards.ie/discussion/comment/120558303#Comment_120558303

Class. Hadn't seen that before. Any good sources on YouTube or that I could read on that?

It's Dublin so wouldn't have windows open downstairs overnight sadly. Did a quick Google. I could get some vent that pulls in on the ground floor (cold night air) and vents out upstairs. Current issue is the heat rises upstairs (of course) and has no where to vent at night.

Mr Q

https://www.boards.ie/discussion/comment/120557201#Comment_120557201

I don't live in Dublin but outside of it was certainly very warm for times last summer without any cloud, rain etc.

To me 23 degrees is excessive heat inside so I would cool the house.

It is a good option to have if you are already paying to install a heat pump, a no cost option in my case.

sydthebeat

https://www.boards.ie/discussion/comment/120558414#Comment_120558414

you dont need windows, youd just install a stack vent in the ceiling of the uppermost floor and make sure there is permanent ventilation in your habitable room, which you should have anyway. Its a good passive measure for cooling if you cannot cross ventilate.

this is a good simple explainer

https://www.eco-home-essentials.co.uk/passive-stack-ventilation.html

or if you have more time and want to go very indepth

https://www.youtube.com/watch?v=PBk1G2F7paY

gandalfio

https://www.boards.ie/discussion/comment/120559046#Comment_120559046

Is this similar to how mechanical extract ventilation works?

Snugbugrug28

https://www.boards.ie/discussion/comment/120557201#Comment_120557201

Really the issue is that my wife wants to control the temperature of my daughters room and keep it around 21 degrees. We have an A2 rated house with oversized windows under the flightpath for Dublin airport so opening the window isn't really an option.

sydthebeat

https://www.boards.ie/discussion/comment/120560401#Comment_120560401

Yeah similar Principe, but with passive stack the movement is induced by passive pressure (warm air rising, wind blowing over the stack etc) while mechanical extract usesb electrical power to induce the air movement.

paddyman

Hi guys,

Can i get some advise here. I want to double check some heat pump size that have been recommended to me.

I got a Part L done and while talking to the guy he advised he usually does the heat pump assessments but is not registered at the moment so gave me the name of a person. While talking with him he advised i would need an 8kw heat pump.

I had the heat pump assessment done and have the HLI / BER etc and while talking with the assessor who done it he advised it should be the installer recommending the size based on the report.

Spoke with the installer who advised he recommends an 8KW heat pump, but wants to check with the manufacturer. So fine, we check with Mitsubishi and their sales / technical desk recommend a 10kw heat pump in size.

From the basic research / googling i have done 8kw seems to be what i believe it should be.

So what is the advise here?. I have HLI report and Part L and BER report, but i am getting conflicting advise from Assessor, installer and Manufacturer. I want to be sure and get this sizing right...

Thanks all,

Paddy

ECO_Mental

https://www.boards.ie/discussion/comment/120571824#Comment_120571824

I have a 12kW A2W heat pump that does all my heating and hot water. I have a 230m2 A1 rated house.

What size is your house, how many people, what's the BER rating, will it have underfloor heating all these determine the size.

I would trust the experts though and I am no expert....

paddyman

Thanks for the input. Its a retrofit of a 60 year old single story bungalow.

The floor area is about 160SQM (no vaulted ceilings) , BER is expected to be A3, UFH + A2W heat pump. the HLI is at 1.84 (according to assessment i got done). 2 x people in house.

I am happy to trust the experts :).

(just FYI - no solar at the moment, but i will be adding it later on + EDDI, just budget constraints for at least a year)

Mr Q

https://www.boards.ie/discussion/comment/120573483#Comment_120573483

An EDDI would be a waste of money in my view if you already have a HP to heat the hot water.

I have an 8kW NIBE unit for my house, about 210sqm with UFH for all rooms. Easily big enough to cover my needs.

But as @ECO_Mental said above it will depend on the house and other factors. The experts should know best, the Mitsubishi answer could be very generic without the detail of the other advice you got.

Biker1

https://www.boards.ie/discussion/comment/120573483#Comment_120573483

If your BER assessor can do a room by room heat loss calculation based on the actual building fabric U-values and expected air change rate then I would go with his/her recommendation on the size of heat pump. Anyone else telling you that you need a certain size heat pump without knowing the actual heat losses is just guessing. If you are bringing the house up to current standards then I would be confident that an 8kw heat pump is oversized.

paddyman

Hi Biker - 8KW is oversized or 10KW is oversized?

the_amazing_raisin

https://www.boards.ie/discussion/comment/120573483#Comment_120573483

For some context, my house was A2 rated when built in 2017 and has a 6kW heat pump for 140 square meters which generally doesn't have much trouble keeping the house warm

So 8kW sounds about right for your house, I don't think you'll have issues with the house being cold

From the information online it seems that oversizing a heat pump can be as bad as undersizing one because it'll tend to cycle the pump more often which lowers your CoP

Dozz

https://www.boards.ie/discussion/comment/120571824#Comment_120571824

Get a reputable company to design the system (and stand over the design) and also use one of their recommended installers.

At least then you should have some warranty & fall back.

Id also ask them what is the design flow temperature is for the system that they are proposing as the lower the temperature the more efficient the system

JayBee66

Does anyone have an A2A heat pump in an approximately 160m2 bungalow? What size heat pump are you using and how many heating units inside your house?

Our bungalow is currently rated at B1 with a HLI of 1.94

THE ALM

https://www.boards.ie/discussion/comment/120574377#Comment_120574377

Not A2A but A2W and currently getting quotes etc.

165m2 2006 bungalow A2 rated with a HLI of 1.78 and an airtightness of 1.376, all radiators. Using the SEAI doc I have calculated total heat loss as 6.645kW.

So far the quotes are coming back with a heat pump of size 10-11kW.