Heat Pumps - post here.

KCross

https://www.boards.ie/discussion/comment/120964135#Comment_120964135

my plumber last week said that besides DHW the heat pump will only come on every 10 days or so in the summer to get rid of the risk of legionella.

Just to be pedantic or clear... the legionella program is for your DHW. The HP will simply run for a bit longer every 10 days to raise the temp of the hot water beyond what legionella can survive in. It will be running most days anyway for the hot water. The UFH should be off during the summer.

During the summer, the HP shouldn't be "ticking over". It will auto turn off and just heat hot water. Or at least that's how it should be configured.

ColemanY2K

https://www.boards.ie/discussion/comment/120964633#Comment_120964633

indeed the calcs say the UFH isn't needed but that all sounds well in theory, the reality is once the floor is poured it ain't coming back up.

ColemanY2K

https://www.boards.ie/discussion/comment/120964665#Comment_120964665

badly worded by me. i meant apart from coming on for DHW the only other requirement to come on is to heat the water to rid it of legionella or the risk of legionella.

Cyrus

https://www.boards.ie/discussion/comment/120964683#Comment_120964683

but it will work that way anyway if its configured to come on at a certain temp, if temps are above that it wont have to kick in regardless.

newhouse87

https://www.boards.ie/discussion/comment/120964653#Comment_120964653

I have 150mm under the screed. Have air tightness membrane/strips etc but tbh we didn't do it with cabling in attic as engineer reckoned its overkill and not much benefit. We have 150mm metac between joists so may ad to that in future as i think its needs itz one area i think could do with improving. 242sqm bungalow i built. Def needs heatpump enough in winter though.

ColemanY2K

https://www.boards.ie/discussion/comment/120964975#Comment_120964975

metac has a declared thermal conductivity of 0.034 meaning 150mm is currently giving you a u-value of approx. 0.186. If you add 100mm of mineral wool it will bring the u-value down to 0.131 and 200mm down to 0.101. at this point it becomes a case of diminishing returns the more insulation you roll out.

if accessible, you can always buy airtightness tape and airtightness sealant from a local builders providers. Then seal off the penetrations where the cabling passes through the airtightness barrier into the attic. last week I discovered a 20mm hole the electrician made. when i put my hand up to it i could feel a significant draft which was then sealed up immediately.

for able bodied people the above tasks are fairly straightforward DIY jobs which would contribute greatly to a reduction in heat losses.

newhouse87

https://www.boards.ie/discussion/comment/120965491#Comment_120965491

So you reckon i should add mineral wool? or is 0.186 acceptable? Thats the attic floor where i have the metac, nothing overhead as was advised against it as house needs to breathe.

ColemanY2K

https://www.boards.ie/discussion/comment/120965510#Comment_120965510

any insulation will do, its just that metac is a lot more expensive than generic mineral wool from lets say knauf. without seeing your attic i can't comment any further but as far as breathing goes the thermal envelope should be sealed and the attic naturally vented through, for example, vent tiles and soffit vents.

the current building regs state the u-value at ceiling level should not exceed 0.16 so you are not far off the 2021 regs.

as i said earlier the building regs are only the minimum standard you need to meet. there's nothing stopping people going over and above what is required. the more insulated and airtight the less heat that will escape.

newhouse87

https://www.boards.ie/discussion/comment/120965635#Comment_120965635

ah yeah it has tile vent and soffit vents. Yeah i will add mineral wool before i floor main part of the attic, fell through ceiling once during building stage so cant have plasterer coming back again to replaster a third time ha.

ColemanY2K

https://www.boards.ie/discussion/comment/120965701#Comment_120965701

its easily done 🤣

plasterman

Just posting here on the off chance if anyone has a recommendation for an installer in Limerick or Galway. DM me if you've had any recent good experiences. For an Air to Water pump. Rang a fair few last few weeks. Promising to come out to quote. Never do. Or even call back. Two guys told me they were too busy, appreciate the honesty. It might be the guy with the limited online presence who is best, and available!

DM me if you've any recommendations, thanks!

unkel

https://www.boards.ie/discussion/comment/120964633#Comment_120964633

I'm far from an expert, but I would have thought the same. 8 * €10 amazon heater on smart plug + €20 immersion element on smart plug and that €200 total spend is your smart heating + smart DHW hardware sorted for a smart passiv house? 😂

HotSwap

https://www.boards.ie/discussion/comment/120967115#Comment_120967115

Not sure what happens to a BER if you have no primary heating source. Maybe it’s ok? You would still be better off with the heatpump because of the COP multiple Vs using direct electricity.

unkel

https://www.boards.ie/discussion/comment/120967138#Comment_120967138

Depends on the cost of the heatpump setup, that COP multiple and the annual unit usage, plus of course the price of a unit ;-)

ColemanY2K

https://www.boards.ie/discussion/comment/120967138#Comment_120967138

The lads are correct in the sense a heat pump is not technically necessary if I went down the cheap heater and smart plug route BUT we don't have a stove. From my understanding without a primary heat source (i.e. the HP or stove) the house cannot be signed off by the engineer at completion.

The UFH on the other hand was my choice just in case I had ballsed up the calcs haha (tbh i find it hard to believe the 193m2 single storey house has a heat load of just 1226W and an annual heating demand of 2,507kWh but that's what the passive house planning package spat out and I've checked and checked the inputs without finding an error).

HotSwap

https://www.boards.ie/discussion/comment/120967863#Comment_120967863

Is that 1266W at -5C? That’s really incredible. Run a PC mining some bitcoin heat your whole house.

Have you played around with the BER online tool that the assessors use?

https://deap.seai.ie/

unkel

https://www.boards.ie/discussion/comment/120968222#Comment_120968222

I have two mining rigs doing exactly that and using pretty much exactly that wattage in total 😁

Just switched them off (they ran overnight on battery from yesterday's PV) as the weather today looks worse than predicted and my battery is low...

ColemanY2K

https://www.boards.ie/discussion/comment/120968222#Comment_120968222

no i haven't but I must do.

heat load calculation below 👇

the temperature figures are standard numbers already inputted into PHPP. The note says weather 1 is a cold clear day and weather 2 says moderate overcast day.

HotSwap

https://www.boards.ie/discussion/comment/120970226#Comment_120970226

What would it change to if you changed it to -5C out of interest. If it’s possible to change it.

Denis sons Demise

Hi folks,

Went searching but couldn't find an answer, hoping someone can advise.

Recently moved into new build since May. Heat Pump system installed is a Joule Cyclone Cy200l. Have only notice in the last two weeks, the pump seems to be kicking in non-stop at night time (only) between approx 2200hrs and 0700hrs. There's a gap of approximately 40-50 seconds between each kick in (she timed it as its driving her mad).

I've narrowed it down to the tank in the attic as what is making the noise, but apart from a basic examination of the tundish in the hot press I don't really know what I'm looking for to narrow down the cause, or even if there is an issue. I'm just concerned that I could be facing parts wearing out faster and/or an expensieve bill.

Any advice on where to start, review, examine, or search, to narrow down the issue? Many thanks.

ColemanY2K

https://www.boards.ie/discussion/comment/120970763#Comment_120970763

1,889w.

Nelbert

https://www.boards.ie/discussion/comment/120971043#Comment_120971043

Are you sure it's night time only? Our cold tank now has a pump too so we get good pressure for hot and cold water all over the house and this sounds like the intermittent on / off of the pump we'd get if someone left a tap somewhere slightly open.

Your heat pump on the other hand shouldn't really be doing much other than heat your hot water at the moment and it would do that in an hour or less most likely. Hence my need to clarify what's actually running...

Other things that cause the intermittent thing are dishwasher and washing cycles, if you've a cold water pump like me that could be a factor.

irewestlad

I’m hoping to move to a heat pump next year. What’s the next obvious couple of steps to take now to get ready for that? Heat/loss survey of house?

Any recommendations for someone in Galway/Clare who would be good to get?

Denis sons Demise

Thanks for the reply. I'm definitely not up on my jargon for plumbing, so I am probably not explaining it clearly, apologies.

It's definitely the same sound as what comes on when water is dispensed (shower, for instance) but there is nothing running at night. I'd hardly have a leak would I at this point?

Thanks for the reply

Nelbert

https://www.boards.ie/discussion/comment/120971633#Comment_120971633

Well.... If you don't have water running intentionally.... And the pump is coming on..... It's a faulty pump or a faulty pipe...

If the pump isn't the issue the intermittent thing is based on pressure, something's slowly releasing the water / pressure.... The pump senses it and turns on.... Then stops when it's pressured again.... Hence for me it's the kinds leaving a tap every so slightly on.... Worst was when I turned on the sprinkler valve while on holidays and then when closing it, it didn't quite close fully so the pump ran intermittently for hours... So it on the energy monitor and got my dad to go to the house and close the valve by hand. Have been planning to replace the valve ever since.

Nelbert

https://www.boards.ie/discussion/comment/120971627#Comment_120971627

Heat loss and air tightness survery / test. Then insulate and address the air tight issues if possible.

Underfloor heating is a great way to run a heat pump if you can, both aesthetically (no rads) and running it at low flow temp which improves efficiency.

Dozz

If you have no visible leaks or taps etc left running, check for a toilet cistern releasing water into the toilet bowl.

Can only be dribble and can be hard to spot.

graememk

Possibly best ask in the plumbing forum, bit more experience there too.

If you could isolate the power to the pump to make sure it is that would also be useful

poker--addict

https://www.boards.ie/discussion/comment/120972015#Comment_120972015

It sounds like a water pump running not a heat pump?Put some of the blue or green domestos around the toilet rim. Easiest way to see it one of them is running water slowly

Denis sons Demise

Thanks for the suggestions folks, will follow up thanks a million!