High wall heatpump. Completely different quotes. Ideas on placement and size

Forums › Home Workshop DIY › High wall heatpump. Completely different quotes. Ideas on placement and size

RickW

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#210400 25-Mar-2017 23:38

Hey guys. We're looking for some advice on heatpumps, placement and sizing.

It is for a new build that will have r2.5 walls r5.0 ceilings and double glazed windows.

We have had a few different quotes that seem to vary a huge amount. Ove saying to have 3 3.7 kw units, one in the lounge and one at each of the bedroom wings. Another has said to have a 9kw in the lounge and to use a heat transfer to the bedrooms to take the chill off. And another saying just a 6kw in the lounge.

Any advice would be appreciated.

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#1747790 25-Mar-2017 23:54

Since the house will be well insulated, Just get a correctly sized heatpump for the lounge and then see if you even need much heating for the bedrooms. Don't bother with a heat transfer system. As that ducting is normally only R0.9 insulated.

And just get the sparky to put the bedrooms on separate power circuits. So they can be tapped into for running heatpumps later if needed. And possibly get him to use a larger size cable for those circuits as well.

Bit hard to give more comments without knowing where in the country you are.

RickW

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#1747791 25-Mar-2017 23:57

Sorry diddnt even think about location, were in christchurch. Yea I was thinking about leaving the bedrooms and just doing the lounge and reassessing after a winter in the house. What would you think in terms of sizing for the living space?

Aredwood

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#1747792 26-Mar-2017 00:18

Can't comment on a recommended heatpump size as Im in Auckland. But partly related, what size hot water cylinder are you getting? And are you having gas or electric cooking?

As recommended getting a 300L Cylinder and Gas cooking. So you can limit peak time power usage. And the large hot water cylinder can be used as a thermal battery to massively increase the return of solar if you get solar installed later. As you heat the cylinder using power that would otherwise have been exported to the grid.

RickW

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#1747812 26-Mar-2017 00:26

Were going for a 250l cylinder and induction for the cooktop as there is no reticulated gas and cylinders are too expensive. Yea we're getting the house prewired for solar and also a 32a circuit in the garage for charging an electric car. The house is steel framed and it's apparently a lot harder to run cable at a later date. I diddnt think about the cylinder, I'll look at making it a 300l.

timmmay

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#1747832 26-Mar-2017 06:27

Heat pumps are noisy, blowing air around a bedroom would be quite distracting I imagine.

Have you consider either under floor heating or radiators? Nice heat, no noise, and can probably be run efficiently off a heat pump. Central heating should be standard in NZ houses, NZ is a cold country, similar to the UK.

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#1747835 26-Mar-2017 06:53

timmmay:

Heat pumps are noisy, blowing air around a bedroom would be quite distracting I imagine.

Have you consider either under floor heating or radiators? Nice heat, no noise, and can probably be run efficiently off a heat pump. Central heating should be standard in NZ houses, NZ is a cold country, similar to the UK.

I get used to it. Because it's cheap. We live in barely insulated 60s house with single glazing and thinned out ceiling fluff.

8 heatpumps. Everything electric, no gas.

Winter power bill - $250.

Dunedin.

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timmmay

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#1747843 26-Mar-2017 07:47

I live in a 100 year old house with retrofitted double glazing, wall, ceiling, and underfloor heating. Two heat pumps (kitchen/dining and lounge), with oil heaters for overnight in the bedrooms. It's never as warm as an English house with radiators, and I have to turn the heat pump to super quiet and the TV up a bit. Not a big fan of the Nocria, the Daikin is quieter.

RickW

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#1747873 26-Mar-2017 08:36

We have a heatpump in the hall at the moment a little dakin 35 that we had installed when my son was born and if it's set to 18 and quite mode overnight I can't hear it in the bedrooms. It's 50/50 that we want ac and My partner isint keen on Tile or polished concrete except in the kitchen, bathrooms and entrance way. I was even contemplating running pex to those areas, how much room do you need for the indoor units with the hydronic system?

jamesrobert

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#1747874 26-Mar-2017 08:39

Put a floor mounted Daikin in our bedroom for heating and cooling. Never hear it, and it is extremely economical to run.

scuwp

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#1747887 26-Mar-2017 09:17

Heatpumps in bedroom are common now, and new technology makes them damn quiet. Another thing missing in this discussion is 'how' you use the house. For example if you have young children that go to bed early and the bedroom doors are closed then don't expect residual heat from the other rooms to make an impact. You may need a more direct bedroom heating solution. If I have my time building again I would look at a central aircon (not forgetting the increasing need for cooling in summer).

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sbiddle

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#1747889 26-Mar-2017 09:18

I think lots of people completely overlook floor mounted units. We have one here and it really is the perfect solution for the house.

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Juicytree

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#1747902 26-Mar-2017 10:11

I agree with sbiddle, a floor mounted unit is best suited for the Christchurch climate. High mounted units are for hot climate places and are used for cooling (cold air falls) and floor mounted units are used for heating (hot air rises soon enough without pumping it out at ceiling level). For some unknown reason the floor mounted units are always more expensive and I sometimes think that is the reason some southern people fit high wall units although you do need the required wall space for a floor unit. I have two floor mounted Daikens in Geraldine.

RickW

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#1748165 26-Mar-2017 16:57

We looked into the floor level ones but efficiency (cop?) seems too only be in the high 2's to low 3's in terms of the energy in vs out but the wall high walls seem to be in the low to mid 4's. I take it that's best case? Is there that much of a difference in real life and in terms of power bills?

sparkz25

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#1748211 26-Mar-2017 18:03

what about a ducted heatpump that does the whole house?

RickW

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#1748216 26-Mar-2017 18:10

Just the issues that others have had on here getting them right has kind of put us off the ducted systems.

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