Heat Pumps - post here.

HotSwap

https://www.boards.ie/discussion/comment/120749797#Comment_120749797

That’s my plan. And I’m giving priority to the two dormer bedrooms as they get very hot.

The Daikin multi plus unit supports 3 internal units (I’m going for the “stylish” unit in black) and also the hot water tank.

I have 7.5kwp of solar and I feel I’d need more panels (which I do have space for) to make this work out without me needing to start paying for electricity again.

I already have a portable A/C unit that draws 700W and it’s enough to cool our bedroom (30m2) so I have no doubt that the 1kW wall units from Daikin will have enough power.

Id love if someone could get a quote for this same setup; or even a whole home air 2 air (with the grant) to see if I’m just causing myself pain by trying to go the DIY route.

micks_address

https://www.boards.ie/discussion/comment/120752422#Comment_120752422

I got this quote earlier in the year

A Multi + system with the max. of 3 hi wall units and a 120 litre cylinder would cost in the region of €10400 + vat @ 13.5%, with a 90 litre cylinder €10000 + vat. Subject to survey.

DC999

https://www.boards.ie/discussion/comment/120752422#Comment_120752422

Could u pop in the link to the portable 700w A/C you got? Looking for one that has a low draw for a small area. Cheers

micks_address

https://www.boards.ie/discussion/comment/120752758#Comment_120752758

this is the one i got - its out of stock everywhere though

https://www.ebay.co.uk/itm/266307146375?hash=item3e01249287:g:0SAAAOSwLA1kkt9x

Runs less than 700 watts.. its noisey.. works though.. just makes me wish i had proper cooling throughout the house!

HotSwap

https://www.boards.ie/discussion/comment/120753091#Comment_120753091

Mine is AEG also; I got it on adverts.

A friend of mine found this and said he was going to get one of these:

https://www.ecdgermany.de/en/Article?s=Air+conditioner

ill ask him if he did.

HotSwap

https://www.boards.ie/discussion/comment/120752454#Comment_120752454

Ok. So the guts of 12k (11804) with VAT. And I can source the materials for 5200. That’s excluding the pipes.

This is very helpful.

ColemanY2K

are there ASHP's out there that are not compatible with solar panels? i'm looking to buy a thermia heat pump and noticed this statement in the blurb...

"Moreover, Atec offers a versatile system that is compatible with a wide range of additional products such as solar panels, back-up boilers or a swimming pool."

surely all heat pumps work with solar panels. i mean the power generated is shoved into the consumer unit and any excess can be redirected via eddi to the tank so not sure why thermia felt the need to put that statement in. their itec eco brochure notably doesn't say anything about panels.

HotSwap

https://www.boards.ie/discussion/comment/120754917#Comment_120754917

I’ve seen on some YouTube videos that there are some units that accept both DC and AC. But I assume that they are talking about some option that allows you to only turn on the unit when there is excess solar being exported.

DC999

https://www.boards.ie/discussion/comment/120754917#Comment_120754917

Yes to 'surely all heat pumps work with solar panels' - you nailed it in your last para above

Mr Q

https://www.boards.ie/discussion/comment/120754917#Comment_120754917

Are they definitely talking about solar PV and not solar thermal. They could mean an extra coil in the tank for another heat source.

the_amazing_raisin

https://www.boards.ie/discussion/comment/120755011#Comment_120755011

That was my thinking too, I've seen several heat pumps specifically advertising this

micks_address

https://www.boards.ie/discussion/comment/120754873#Comment_120754873

If you can fit it in my house I'd be happy to work with you!

HotSwap

https://www.boards.ie/discussion/comment/120755144#Comment_120755144

I’d be struggling to find the time to do my own. But at least it’s good to know significant savings to be had via the DIY route. The only bit that it’s not possible to DIY is pressure testing and filing the refrigerant pipes.

Mr Q

https://www.boards.ie/discussion/comment/120755995#Comment_120755995

What about the pre gassed split units you can buy? You wouldn't need anyone else to do any of the work. Assuming they would work for your situation.

the_amazing_raisin

https://www.boards.ie/discussion/comment/120750855#Comment_120750855

Yeah I definitely agree it's worth doing it properly, just not 100% sold on the idea that the concrete slab won't heat up

Most of the mats look like a giant egg crate (I think one of them is even called procrate) and while you'd definitely lose some degree of heat transfer because the pipes aren't in contact with the concrete, the slab will eventually heat up. After all it's inside the insulated space so there isn't really anywhere else for the heat to go

Personally I'd probably go for the thicker mats to use normal sized pipes, don't really see any issues with raising the floor a couple of centimetres, but I can definitely understand it can cause issues for things like doorframes or built in cabinets. I guess that's partly behind the all or nothing argument

Also, I'm a good fan of laminate. Engineered flooring does look great but for ease of cleaning or durability I think laminate is hard to beat

I've a load of high quality tiles in my kitchen which I hate and want to replace. I'd quite happily replace them with those tile effect laminate boards. I even floated the idea of a decent vinyl floor but the glare I got from the missus pretty much scuppered that, she said something about not wanting to be reminded of her parents kitchen 😂

the_amazing_raisin

Okay, stupid question time

I'm trying to get my head around UFH manifolds and heat pumps

Some of the manifolds I've seen have the option of putting actuator valves on each of the flow lines, so you can basically zone out some of the rooms. They weren't heat pump specific ones but more designed for any heating system

But....why? I get the general gist of not heating rooms you don't need to but in an insulated house that seems pretty pointless. It just means you're using one room to heat every room effectively

And isn't the idea with UFH in particular to slowly heat up the whole concrete slab to act as a kind of storage heater?

Also, for heat pumps in particular, you generally want to run the thing for a long time on a low output. So having rooms constantly calling and stopping heating would detroy your COP. In fact I think Heat Geeks did a video to that effect

So I would imagine for a heat pump you'd want no zones on the UFH system, and you probably just divide most houses into an upstairs and downstairs zones

I do wonder then how you balance the system, say you have a south facing room which gets some solar gains and want to make sure that room doesn't overheat. Is that where the idea of zoning off the UFH comes in?

Seems a bit coarse to just have an on or off type of control, it would be kinda cool if you have some controllable mixer valves and could dynamically lower the water temp of any rooms that were getting too hot

Busman Paddy Lasty

https://www.boards.ie/discussion/comment/120756438#Comment_120756438

You've answered your own question in the latter half of the post.

Zoning cuts down on waste and less waste is très bien.

Every house is individual, have upstairs/downstairs at home and it's not enough zones. Need at least up/down and north/south facing. And bathrooms too. Weather is great now, house is boiling, can't heat bathrooms* (to deal with moisture) because they ain't zoned.

Add into the mix walk in wardrobes, plant rooms, windowless utilities, 6 bedroom houses, porch/hallway with door opened regularly, they won't be perfectly balanced on commission never mind all year round, four seasons, heatwaves and snowstorms. The people living there may not want the same temp in all rooms anyway.

You should only run the heat if it's needed. Anything above need is waste even if the the COP is high. A mid sized house with say 6 zones might turn off 4 **** little rooms (upstairs for example) but still run the heat pump for the ground floor slab, to comfort level, no extra cycling. If the zoning eliminates overheating small rooms and even saves run hours in total that's a only a good thing.

the_amazing_raisin

https://www.boards.ie/discussion/comment/120756587#Comment_120756587

Okay but even zoning down individual rooms with the UFH? Seems like overkill, surely any extra heat is just going into the slab?

But yeah I get you in general, don't want to be turning the downstairs bathroom into an oven just because it's in the same zome as the big kitchen dining room. And I guess unlike radiators you don't have TRVs to gradually close off the heating, so you need an alternative

I wonder what the best way to control the heat pump is then, use the thermostat in the coldest room as the "master" thermostat?

I need to go reading the Daikin manuals again and see if they have any guidelines. To their credit they've got a lot of the integration guides online where any pleb can access them

Busman Paddy Lasty

Stop thinking like a smart person and think like a pleb, join me!

TRVs, similar theory in preventing overheating without needing smarts. The biggest room by volume such as a big open plan dining room is naturally the master in a well insulated house. Short cycling can be prevented by proper setbacks. Better to have the zones and use smart controls than not have the hardware.

redmagic68

https://www.boards.ie/discussion/comment/120756621#Comment_120756621

Check out Rehau for underfloor heating controls. Basically you have masters communicating with the hp. They call for the heat when required. Zoned areas feed info to them as slaves. The masters control both the cycling of the heat pump and which actuators to open to heat the required zone.

it can also be set up that each zone works independently all masters if you like but slightly more expensive.

HotSwap

https://www.boards.ie/discussion/comment/120756621#Comment_120756621

The most efficient way to control any heat pump is to use the manufacturer supplied controls in conjunction with a properly designed system and to use weather compensation (where the flow temp of the heat pump is dynamically adjusted based on the outside temp). And not to have any zoning at all.

You will adjust the flow rate of each room in L per min (each loop could cover more than one room; or more than one loop could be required for bigger rooms) at the manifold as per the design of the system depending on the heat loss calculation of each room.

If you start zoning; and your house is well insulated; the zones that are off will start to be heated by the zones that are on; and ironically it ends up costing more to run.

So what you should really do is ensuring that whoever is designing the system is using the values that you desire for each room rather than some nominal 21c default.

HotSwap

https://www.boards.ie/discussion/comment/120756072#Comment_120756072

If I was doing this it would need to be the multi + system from Daikin as it also heats the 120L tank of hot water using the multi split unit.

Assuming I did a good job installing the pipes; it would be a quick job for an RGas engineer to test and fill the system for me.

the_amazing_raisin

https://www.boards.ie/discussion/comment/120756945#Comment_120756945

See that was my thinking but using temp control valves to control the flow temp of the water

Controlling flow rate is probably a lot smarter since it means you just have one flow temp for the whole system and then you just use a setback temp on the master circuit to trigger the heating to come on

https://www.boards.ie/discussion/comment/120756714#Comment_120756714

Yeah I think I follow you now, design the system ideally so it won't overheat one room like @HotSwap said but also use the thermostats and valves to prevent any rooms from being overheated if circumstances change (like the missus suddenly declaring the house is too hot and turning the heating down to 12C)

omeara1113

Will a heat pump be suitable for a log cabin

graememk

https://www.boards.ie/discussion/comment/120758257#Comment_120758257

Depends!

Heatpumps are just a heat source, it's the plumbing around it (rads, ufh) and can it output enough to make up the heat loss.

the_amazing_raisin

Found the following articles about manifolds which was pretty interesting

https://www.nu-heat.co.uk/blog/underfloor-heating-manifolds-explained/

So it looks like you use the flow valves to control each loop and one or more thermostats to trigger the actuator valves if any rooms hit their max temp

omeara1113

Thanks for the reply graememk

HotSwap

https://www.boards.ie/discussion/comment/120759708#Comment_120759708

Yeah. But if that’s happening it means your system is poorly designed and not as efficient as it could be. Either you’re running your flow temp too high (either you’re not running weather compensation - which is critical); or the weather compensation curve is set wrong; or your running too high a flow rate on the zone that’s overheating.

A lot of installers will purposefully not make your system as efficient as it could be because that typically requires a bit of iteration to refine the weather comp curve; and most couldn’t be bothered.

the only real way to guarantee this is to do your own research like your doing and understand how the different aspects of the system interact with each other.

JayBee66

I think I've read enough in this thread to put me off heat pumps.

1) I'm approaching 60 so I am not going to get any financial benefit from the expense of installing a heat pump. For a variety of reasons I'll be lucky to see 70.

2) I'll go with resistive heating, stick with the wood stove and still have plenty of money left over should the ~100% efficiency not be enough.

3) I don't believe anything the BER conmen have said. I don't believe the house is B1. HLI 1.91? Well, you had to make sure it was under 2.0 otherwise I wouldn't have paid you the E750.

4) Heat the human not the home. When the two of us are in the bungalow, we are usually in the same room. So long as the wood (I'm rural so it's freely lying around everywhere) stove gets the living room up to 20C and the bedrooms (two because I snore like a pig farm) to 16C with either FIR/ceramic/storage heaters the rest of the house can be damned.

5) Our dehumidifiers do a great job controlling the damp throughout and we can run another heater when the home office is used. I see no point heating rooms that are not used or infrequently used. Better to take care of the humidity rather than the temperature. Even in summer our house at 23C is more comfortable at 55% RH than 70% RH so no need for fancy AC either.

6) I visited enough heat pump installers and listened to their vague answers to think it's all hit and miss. Either the installers get lucky or they don't. You are either young, wealthy or both and it's just another big ticket purchase you go through whilst working. I shan't take that risk.

Heat pumps are not for me. I'm retired, hardy and would rather use the money for something else.

ColemanY2K

https://www.boards.ie/discussion/comment/120755011#Comment_120755011

Fair point. I automatically assumed PV.