Heat Pump Placement Confusion

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#1782483 15-May-2017 12:40

Firstly congratulations on getting your first home.

I am currently building, and while I was somewhat complacent about where they were going to put the heat pumps in, they did make good recommendations on where to put them. Both of my heatpumps are currently being installed on the outside walls. I was TOLD that they must be about 200mm below the roof. Which did annoy be a bit, as I had plugs installed for a TV on the same wall. But I am just going to lower the TV a little bit, or maybe put a smaller TV in one of the rooms.

As for the size of the heat pump. When I got one installed in my old house it was pretty confusing.

Firstly, you should make sure you home is insulated in the roof walls and floor (if possible) before buying the heatpump. You may or may not be eligible for a government grant. Check the Energywise website. My old house was built in 1965 and had no insulation. So i installed some under the floor myself. I couldnt get into the walls to insulate, and the roof didn't have a cavity. So I ended up going with a larger heatpump 6.25 K/w and it worked well. (It heated/cooled a maybe 40~50Sqm Lounge/kitchen that was poorly insulated. (floor only) as that is all I could do.

The reason why this is important, is if walls/roof are insulated is a large factor in heatpump sizing. Also insulation doesn't cost power every month.

If you can get away with a smaller heatpump because your home is insulated, it will use less power, & it wont need to work as hard either.

1) Spend the money on insulating first.

2) Then get a heatpump sized based on an insulated home. I was able to use a heatpump sizing calculator to figure out what I needed.

timmmay

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#1782493 15-May-2017 12:49

I wouldn't put wall mounted heat pumps in a new house. They're ugly, and the breeze can make the place feel colder. I might go ducted, but I'd probably go with either underfloor or radiators. Radiators don't cool, but in Wellington we heat 6-8 months of the year and need air conditioning about two weeks of the year. I may have been influenced by my English wife...

I wouldn't put a heat pump over a TV. They have lights, and the air would blow in your face.

MikeAqua

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#1782531 15-May-2017 13:31

Ask to see the maths underpinning the installers' individual recommendations ... when we went through this exercise for our last house it became apparent that only 1 out of 4 installer providing quotes had actually done any maths or knew how to. The one guy that took a quantitative approach was the cheapest and the units did the job nicely and economically when installed. The others who were working subjectively allowed a significant margin of over capacity.

Mike

Fred99

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#1782662 15-May-2017 15:46

timmmay:

I wouldn't put wall mounted heat pumps in a new house. They're ugly, and the breeze can make the place feel colder. I might go ducted, but I'd probably go with either underfloor or radiators. Radiators don't cool, but in Wellington we heat 6-8 months of the year and need air conditioning about two weeks of the year. I may have been influenced by my English wife...

I wouldn't put a heat pump over a TV. They have lights, and the air would blow in your face.

It depends very much on the house design. You lose wall area for chairs, sideboards etc with a floor mounted unit, many modern houses have large windows, doors etc, so wall space may be at a premium.

In some cases they can be partly recessed into the wall so they don't stick out so far but probably not an external wall or internal structural wall unless designed to allow that. (requires removal of a stud).

The wall-mounted units these days come with things like "comfort sensors" with passive IR detectors on the panel - so if that function is turned on then they don't direct air at people.

I'd probably want a floor mounted unit in a bedroom (except I don't like heated bedrooms) - some have a very quiet low fan and "radiant" heat setting where the front panel is heated. Otherwise just put in what works - layout wise.

I was going to put a sub-floor system in, but price of $15k or so seemed overkill. A friend/neighbour put a ducted system in the ceiling which seems to work well enough, but still doesn't get away from ugly with the ceiling vents.

The most unobtrusive heating system I've experienced was my BIL's house in Q'town, with sub-floor in slab and a diesel-fired boiler. The boiler was unreliable and cost a fortune to maintain, then the diesel price doubled and they stopped using the system except for hot-water heating because it was costing a fortune to run. Then with some ground settlement the floor slab on several levels moved, the piping crapped out - and that was the end of that - even though the diesel price had come down it would have cost another fortune to fix. Last time I stayed, they had the open fire cranked up (free firewood off their land).

On the K.I.S.S. principle, conventional heat pumps make quite good sense, especially so if you don't have mains gas or a supply of free firewood.

Cost me $6k to install a log burner - low emissions (ECan clean air zone) but not "ultra-low" which would have cost a lot more. Cost me $6k to install about 9KW capacity 2x heat pumps. While I get it when people say that the heat from a fire is much nicer (but IMO mainly there's something nice about having a real fire) there's a problem with ours except on the very coldest Chch nights. It's too hot - after recladding, insulating etc an older (1960s) home of about 210M2, despite large windows (single-glazed) when we fire it up, then the living area gets way too hot - requiring opening doors etc to rooms that aren't being used.

kryptonjohn

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#1782671 15-May-2017 16:10

We inherited a unit when we bought our current house that is mounted high in the corner of the living room. We're renovating and have opened up the kitchen, increasing the space further to around 9m x 6m. The sparky looked at the heatpump and said "that won't be powerful enough".

But it can heat the room up from dead cold in minutes. And that's with french doors and large areas of single glazing down both sides of the room and no curtains put in yet.

No idea what it's capacity is.

darylblake

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#1782678 15-May-2017 16:28

timmmay:

I wouldn't put wall mounted heat pumps in a new house. They're ugly, and the breeze can make the place feel colder. I might go ducted, but I'd probably go with either underfloor or radiators. Radiators don't cool, but in Wellington we heat 6-8 months of the year and need air conditioning about two weeks of the year. I may have been influenced by my English wife...

I wouldn't put a heat pump over a TV. They have lights, and the air would blow in your face.

So the solution is not for everyone. In my case its more about having the cooling factor in the summer. The next door neighbor who has a very similar house layout to us said she has her upstairs air conditioner on full in the summer. It gets unbearably hot, even if you open windows upstairs.

The house is full brick cladding, with double glazed windows and fully insulated on a concrete pad. So its very warm already. I hope to move in in a few weeks when the driveway is done and the bathroom finished. I looked into underfloor heating, both heated by natural gas and electric and it was not really worth it for the cost.

As for the original poster. I also got a ventilation system in my old house and it was AMAZING. Not necessarily from a heating point of view. But it was much drier. The dehumidifier filled up a lot slower. No more mould building up on the walls and carpet. And in the mornings there was no water on the inside. It was AMAZING. And it did make it easier to heat.

darylblake

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#1782679 15-May-2017 16:29

kryptonjohn:

We inherited a unit when we bought our current house that is mounted high in the corner of the living room. We're renovating and have opened up the kitchen, increasing the space further to around 9m x 6m. The sparky looked at the heatpump and said "that won't be powerful enough".

But it can heat the room up from dead cold in minutes. And that's with french doors and large areas of single glazing down both sides of the room and no curtains put in yet.

No idea what it's capacity is.

If it works, then the sparky doesn't know what hes talking about. Probably just trying to get another job out of you. Id put the curtains in.

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kryptonjohn

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#1782681 15-May-2017 16:37

darylblake:

kryptonjohn:

We inherited a unit when we bought our current house that is mounted high in the corner of the living room. We're renovating and have opened up the kitchen, increasing the space further to around 9m x 6m. The sparky looked at the heatpump and said "that won't be powerful enough".

But it can heat the room up from dead cold in minutes. And that's with french doors and large areas of single glazing down both sides of the room and no curtains put in yet.

No idea what it's capacity is.

If it works, then the sparky doesn't know what hes talking about. Probably just trying to get another job out of you. Id put the curtains in.

Oh hell, the curtains are definitely going in. And not just for the insulation... the place echos like a mausoleum without them.

mattwnz

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#1782709 15-May-2017 18:12

I was using a calculator online, from one the manufacturers websites. However it said I need a 15kw heat pump for one of the room (open plan with high ceiling) . That almost needs a commercial type. However a company who quoted me, only spec'd a 4 or 5kw one. So I am wondering how accurate the calculators are. Or how good the installers are at calculating them. I have also got quotes from 3, and now have provided any calculations, and all have totally different solutions.

Technofreak

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#1782754 15-May-2017 20:11

We are about to put in a heat pump. Had three quotes and all came up with roughly the same size units. So hopefully we will have the correct size. From the online calculators and other material I was expecting them all to quote on a larger unit.

Our choice is a floor unit. Two other family members have floor units and are very happy with them. This helped with our decision in choosing between wall and floor units. Yes, a floor one does soak up some wall space, but we are very confident it will give us a much better heating solution especially with our cathedral ceilings.

Also if you are hoping to get some benefit in adjoining rooms I think the floor units will do a better job of distributing the air.

One thing I cannot figure out is why the floor ones are generally quite a bit dearer.

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Fred99

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#1782793 15-May-2017 21:05

I expect that one reason the floor mounted units are dearer is that they build a bit of a buffer in to the price, as it's probably going to be a bit of a mission to get the pipes and wires to it when installing compared to many high wall mounts where they'll often "back to back" it on an external wall relatively simply.

The two units I had installed of similar capacity, the floor mounted unit was more expensive, but because access sub-floor was very easy, they discounted it to be about the same price as the wall mounted unit.

Technofreak

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#1782800 15-May-2017 21:19

Ours is back to back. In our case the floor one will be much easier to install, but yet two quotes for the floor unit were 20% more expensive.

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richms

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#1782805 15-May-2017 21:25

Has anyone had one of those square cieling ones put in at all? One of those would probably be great in my shed since I dont want to have to give up wall space for them.

Richard rich.ms

mattwnz

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#1782809 15-May-2017 21:30

richms:

Has anyone had one of those square cieling ones put in at all? One of those would probably be great in my shed since I dont want to have to give up wall space for them.

They are the ceiling cassettes. Think someone above posted that they have one.

Technofreak

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#1782812 15-May-2017 21:30

Some floor ones can be mounted horizontally instead their usual vertical mounting and can be ceiling mounted. I'm not talking about ceiling cassettes.

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