Heat Pumps - post here.

Calahonda52 · 11-09-2022 8:45am

https://www.boards.ie/discussion/comment/119600665#Comment_119600665

It's not the suppliers call, it will need a post install tech assessment by an SEAI approved assessor.

Ideally a projected BER based on proposed upgrades will tell you where the HLI is at

I see at last one a week where in the post install assessment either the HLI test or the 300% efficiency test are failed

If either are failed, no grant and remediation is tough

majo · 11-09-2022 1:33pm

https://www.boards.ie/discussion/comment/119602182#Comment_119602182

Thank you for that info. Much appreciated

Calahonda52 · 11-09-2022 9:47pm

https://www.boards.ie/discussion/comment/119603078#Comment_119603078

Your welcome, its you money on the line, not the suppliers

jimmyekehoe · 11-09-2022 10:27pm

Ive a 6kw Solar system installed with 4.8 battery. We also have and Eddi and Zappi for an EV and PHEV, so use the majority of what we produce. I charge everything at night between 2-5am on the bord gais 5.5c per kwh rate.

In the next two months we are getting triple glazing windows, all external doors replaced, cavity insulation and more insulation into the attic which should take our BER from B2 to A. Ive somebody doing a technical assessment for a heat pump soon as Im thinking of replacing my LPG Gas boiler with an Air to Water heat pump.

My question is about using solar with an Air to Water. Assuming the house is efficient enough for a heat pump, is it practical or possible to run a heat pump from Solar if I was to add more panels up to say 10kw and add batteries to run it when its dark havibg been charged at the low EV rate.

Ive been researching it but hard to get a sense of the power usage of a heat pump in a circa 300sq meter/3500sq ft house.

Does anybody have experience to share of runnning (or part running) a heat pump via solar in an Irish winter…

redmagic68 · 11-09-2022 11:30pm

https://www.boards.ie/discussion/comment/119605488#Comment_119605488

If you wait a few weeks I’ll have some data on that. Currently running a 14kw Daikin high temp heat pump for hot water. 275 square metre house A3 rated with four people having showers etc

Our average daily usage for the house has been 19kw for the last 6 weeks. The heat pump has averaged 2.5kw for hot water heating and sterilisation cycles per day during that time. Granted we have solar thermal installed also so as the weather gets worse I expect the 2.5kw to move closer to 3kw. This is all on night time units however.

The space heating will come back on in about 4-6 weeks depending on weather and then I’ll be able to monitor the extra units needed for heating. If you pm me then I’ll let you know usage.

Calahonda52 · 12-09-2022 9:09am

https://www.boards.ie/discussion/comment/119605488#Comment_119605488

This is really a question about running a heat pump in winter from batteries charged during a 3 hr window.

You need to include the math on losses.

My view, if you have the room, is get a thermal store, as you will be heating the rads during the day since you don't have UFH.

The other thing to consider is if the HP fails for some reason, the back up is at a COP of 1, which could be 14kWs, depending on the HP.

Redmagic what is the flow rate temp form the HP and what is the COP/

redmagic68 · 12-09-2022 10:15pm

Flow for hot water is 55 degrees that’s the minimum setting for the hight temp unit I have. Cop is rated at 3-1.

littlekiller · 18-09-2022 10:47pm

Sorry if this isn’t the right place to post, but you all seem a LOT more knowledgable than me on this!

I’ve a Daikin heat pump (EHVH04SU23EA6V) in my new house that I can’t figure out how to connect to my WiFi network, so I can’t use the app, or really figure out how to control it at all. The instructions I can find online/on the app are for a different model, so I’m pretty stuck. I’ve tried clicking through all the options on the unit itself, but the closest one is a status for the wireless gateway, and each time I select it, it simply reverts to the previous screen. I have followed the troubleshooting instructions on the app, but they are for a different model.

The pic below is of the homescreen on the unit itself—any advice/help appreciated.

redmagic68 · 18-09-2022 10:59pm

https://www.boards.ie/discussion/comment/119635705#Comment_119635705

You should be able to find the manual for any Daikin online just search the model number.

my unit is heading for 12 years old so don’t have an app interface.

you could also email Daikin in Dublin they’re pretty helpful I’ve found when needed, or the installer should have given you a walk through or even set up the app with you.

I’m sure someone on here is probably running something close to yours and will know better than I.

littlekiller · 19-09-2022 3:43pm

Thanks a million! They were quite helpful til I asked how to get the WLAN cartridge added in, as it really should’ve been included in installation (especially since there’s a big sticker on the front of the unit advising you to use the app, which you can’t do without the WLAN).

KildareP · 19-09-2022 4:06pm

A very uneducated question - so apologies!

I know heat pumps are intended to be left "on" 24/7 as opposed to being on for short bursty cycles like a typical oil/gas boiler but how quickly can a heat pump get up to temperature from cold, such as if you're away for 2 weeks and return home?

Or let's say a room that's unused and unheated and so is significantly below temperature, rad is switched on from stone cold, how soon will that rad be at the set flow temperature?

Current setup is oil, all rads, no underfloor, flow of 40C except in extreme cold (e.g. 2017) and it's pushed up towards 50C, and that can get our rooms at or near temperature within 1-1.5 hours from a "cold start" with most of the rads TRV practically fully closed. B3 BER. Boiler is timed "on" for 3 hours in the morning and 4 hours in the evening and we use 1200-1500L of oil in a typical season.

Anyone with any experience on how a heat pump would fare in comparison?

graememk · 19-09-2022 5:10pm

Your flow temperature is already in heat pump territory.

How fast a room heats up depends on the radiator in the room. As you already have your flow temperature down at 40c, you can run your experiment yourself.

40c water is 40c water be it from oil/gas/heatpump/electric.

The heat loss of the whole house would determine the size of the heatpump.

KildareP · 19-09-2022 7:00pm

Suppose what I'm asking is will a heatpump get the rads to 40C from cold within an hour? 2 hours? 6 hours? 24 hours? I'm assuming it won't do it in anywhere close to the 20 mins the oil takes...

redmagic68 · 19-09-2022 9:38pm

https://www.boards.ie/discussion/comment/119638863#Comment_119638863

So for an example. We needed hot water this evening as the storage tank had been used up, high demand day. The water was sitting at 28 degrees at the top of a 300l tank. The hp took it to 55 degrees within 90 minutes, the coil being two thirds way down the tank. This usually takes about 2.5-3kw of power. While not exactly the question you asked it should give you a pretty good point of reference.

If you take it that was about 160lt of water you could pretty much work out the volume of your Rads allowing for circulation etc. It won’t do it 20 minutes though no, nor is it designed too.

graememk · 19-09-2022 9:56pm

https://www.boards.ie/discussion/comment/119638863#Comment_119638863

"It depends" but generally it shouldn't take long. If your oil boiler was 20kw and the heatpump 10kw, it will be about twice as long.

On how many radiators and what the output is and what size the heatpump is.

But oversizing the heatpump isn't good either, would mean more cycling, losing efficiency.

KildareP · 20-09-2022 8:55am

That's brilliant, cheers both!

walkonby · 20-09-2022 10:32am

Hi all, I currently live in a decades old mid terrace house with gas heating. Abysmal ber rating. I am going to get external insulation, new doors and windows and attic insulation to bring it up to b rating.

I am wondering is it worth getting a heatpump as well. I would be getting new radiators but I wouldn’t have underfloor heating. Is the pump worth it without that?

graememk · 20-09-2022 10:38am

https://www.boards.ie/discussion/comment/119640731#Comment_119640731

You don't have to go heat pump, do get quotes though.

If your replacing your radiators, do look to get them oversized with a heatpump in mind, even if you don't get a heatpump now, it will make your gas run more efficiently.

UID0 · 20-09-2022 11:18am

Maths is great for calculating this sort of thing.

Your heating system probably contains about 50-100l of circulating water. You can work out the exact amount by adding up the amount in each radiator and the water in the pipes to/from the radiators and the boiler. This is what needs to be heated to 40C.

Water has a specific heat capacity of 4.2J/g DegC

For 100l, if the house is at 12 degrees after you arrive in from your holiday, then that water needs to be increased by 28C, which will take 4.2 * 100 * 1000 * 28, which is 11760000J of energy, which converts to 3.267kWh. If it's 50 l, it's half that. There's a bit more than that needed as the radiators will start losing heat to the room immediately, but the amount of heat output by the radiators is dependent on the difference in temperature between the radiator and the room, so it won't add too much to the startup time. To work out how much time it will take, you have to look at how quickly your heatpump can output that much heat at the outside temperature.

The other thing is that to run at its most efficient, heatpumps should be set up with weather compensation turned on. The basic premise of this is that heatpumps run more efficiently the lower the circulating temperature. If it is warmer outside, the house is losing less heat to the outside, and therefore needs less heat put in by the heatpump. If the pump runs at a lower circulating temperature the cop is improved and the amount of cycling is reduced. The way my heatpump is set up, the outside temperature would have to be around 9 degrees for the circulating temperature to hit 40. The weather compensation curve will depend on how much heat is being lost by the house (calculated on a per-room basis, usually) and the amount of heat the radiators can put into the room.

There's an interesting youtube channel I looked at (Heat Geeks) that gave me lots of questions to ask the guy who did the initial pre-installation survey and the installer so that I knew how it all worked and why some of the radiators needed replacing.

Calahonda52 · 20-09-2022 11:46am

https://www.boards.ie/discussion/comment/119640731#Comment_119640731

HP with rads, without a thermal store, will put a lot of consumption on day rate elec

Mount new windows on outside faceof wall.

munsterfan2 · 20-09-2022 1:23pm

https://www.boards.ie/discussion/comment/119586500#Comment_119586500

Similar size new build, heat-pump has used 1900kw so far in 2022 (for a thermal output of 9696kw). So pretty close to what your estimate of 3,200 was ( I would expect to hit that by end of year). We have 5 adults in house, lots of hot water used. Our electricity bill is between 150 and 250 a month, but we are also running a Nisan Leaf off that.

redmagic68 · 20-09-2022 1:26pm

How are you measuring your thermal output if you don’t mind me asking? It’s something I’d like to do myself to calculate cop accurately.

donalh087 · 20-09-2022 2:49pm

https://www.boards.ie/discussion/comment/119641495#Comment_119641495

I have an app provided with the heating system.

hero25 · 20-09-2022 3:20pm

If it helps, have slightly larger new build with UFH, A2W etc, 5 x adults.

I dont have any apps to measure the various bits, but in terms of units of electricity used .... its been a pretty stable average of just under 14000 units per annum for each of the last 4 years.

simpsimp · 20-09-2022 3:58pm

https://www.boards.ie/discussion/comment/119638076#Comment_119638076

We have (I think?) the same unit, the Altherma 3RF - and I have had zero success getting our installer to locate / add the WLAN module. How did you get on?

littlekiller · 22-09-2022 4:06pm

They’re completely ignoring me at this point, which is very frustrating. Annoyed to hear you’re having the same experience!

AidenL · 23-09-2022 9:30pm

I have retrofitted a 12 kw Panasonic T Cap heat pump to our home this week. Being commissioned next Tuesday, just in time for winter.

Post install BER by Technical Assessor for grant next Friday.

the_amazing_raisin · 23-09-2022 10:00pm

https://www.boards.ie/discussion/comment/119638863#Comment_119638863

It won't be 20 mins but it won't be 24 hours either. I find the rads get up to temp pretty quickly but since the water temp is lower is takes a little while to get the room back up to the right temperature.

So maybe an hour or two max I reckon, just anecdotally on my experience

One neat trick with my heat pump is that it's got a holding mode, so it won't heat the water and will only keep the rooms above 16C when we're away.

But on the last day it'll run a disinfection cycle on the water and bring the house back up to the right temperature, so it's warm when you get home

the_amazing_raisin · 23-09-2022 10:05pm

I'm gonna chuck my hat in on the energy consumption ring. Used 10,500kWh in the past year. Have 2 EVs so around 3-4,000kWh went into those

So the house is using around 7,500kWh per year. Thats for a 135sq meter semi detached with an A3 BER rating. There's at least one person home all the time so heating will be on during the day in winter

Nelbert · 24-09-2022 12:01am

Anyone with an Ecodan had a Mitsubishi call out recently?

My installer contacted me to say Mitsubishi want to come out and install updates to optimise energy usage. I used it as an opportunity to pretend my installer "forgot" to give me the WiFi adapter for the ecodan.... So I now have visibility of energy usage... COP is 3 or better on heating water but below 2.5 for heat so I'm guessing that's the target for whatever update.

Heat Pumps - post here.

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