Heat Pump Water Heaters

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#665300 1-Aug-2012 11:59

Friend has one and the neighbours complain about the noise and the cold draught coming from the unit so it ended up on a timer so it doesnt run at night. Think about where you can situate one before going for it.

They are not inverter heatpumps so have a noisy startup and dont throttle back as they approach the setpoint like a house heatpump does.

Richard rich.ms

Niel

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#665572 1-Aug-2012 17:05

langers1972:
Niel: Their cost in NZ is a bit high, not worth the power saving. Years ago there was a very nice model on TradeMe but it was taken off. I suspect it did not have local approval. But was a very nice unit for half the price of the subsidised retail units.

Of course they're 'worth' the power saving because they're more efficient to run albeit with a higher up front cost.

It seems to be the Kiwi way to only do something if there's something in it for them. Why can't people see the bigger picture in that if we all do something to reduce consumption then in the end we ALL benefit.

Note this isn't a personal attack but a vent of frustration at the general apathy here in terms of efficiency.

No problem, not taking it personal. I'm Afrikaans South African that adopted Kiwi Country and share your frustration regarding some of the characteristics of the culture (all cultures have some good and some bad characteristics).

My point was their retail price in NZ is so high compared to overseas that it will take a long time to take off here. There were people that imported it and sold it on TradeMe, much better spec and I believe it was an inverter with a nice LCD and remote control panel like some gas water cylinders, and it was sold for half the price of the basic Reem model, but I believe it did not have local certification so it could not be sold. It was an indoors single unit with an air inlet and exhaust port so you could duct it, which means in summer you could heat the water and cool the home in one go, in winter you would have to duct both inlet and exhaust to the outside (or ceiling).

If a company was to bring units in at a reasonable price instead of pricing it according to what a solar heater costs plus a bit more for the convenience that you do not need sunlight for water heating, then they will sell in volume and everyone will benefit. A 3kW window mount heat pump is about $400, add the cost of a hot water cylinder then you can see a basic heat pump hot water cylinder should cost maybe $2,000 to $3,000 and it will sell like hotcakes.

Regarding insulation, the problem is that people build according to minimum code. Would you go to a doctor that barely passed his exams? People need to be educated to ask for better quality. I love watching Holmes Inspection showing how you should do insulation.

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kiwitrc

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#665576 1-Aug-2012 17:13

Niel, what is Holmes Inspection?

langers1972

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#665608 1-Aug-2012 17:54

On the Living Channel, he's a home inspector that goes in to fix houses that have problems that weren't picked up in a presale inspection. It'a Canadian show and they know about insulation!!!

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#665659 1-Aug-2012 18:43

kiwitrc: Niel, what is Holmes Inspection?

http://www.mikeholmesinspections.com/
In Canada they lay plywood over the trusses and then shingles. Then the inside gets covered in spray foam insulation. Then a thick layer of insulation on the ceiling. But the ceiling space is still ventilated to keep it dry. Useful comment he often makes is that the house with less snow on the roof has poorer insulation.

Can't remember when it is on Living Channel, think it is Saturday night or maybe Friday night.

You can never have enough Volvos!

kiwitrc

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#665661 1-Aug-2012 18:45

Thanks guys.

Niel

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#665710 1-Aug-2012 20:26

What do you know, Holmes Inspection is tonight 9:00.

You can never have enough Volvos!

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#665729 1-Aug-2012 21:08

It's a shame it's so expensive, even more of a shame i missed out on the previous 500+gst incentive.
I also wonder how much of the brochure's 3 cop @ 6 degree is true.

Asked around in the office today, not many were even aware of such a thing as heat pump water heaters.
Incidentally, saw this article on stuff :
http://www.stuff.co.nz/the-press/news/7349777/Solar-water-heating-no-magic-bullet-study

Handle9

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#665749 1-Aug-2012 21:55

langers1972:
Niel: Their cost in NZ is a bit high, not worth the power saving. Years ago there was a very nice model on TradeMe but it was taken off. I suspect it did not have local approval. But was a very nice unit for half the price of the subsidised retail units.

Of course they're 'worth' the power saving because they're more efficient to run albeit with a higher up front cost.

It seems to be the Kiwi way to only do something if there's something in it for them. Why can't people see the bigger picture in that if we all do something to reduce consumption then in the end we ALL benefit.

Note this isn't a personal attack but a vent of frustration at the general apathy here in terms of efficiency.

Worldwide energy efficiency is being driven by two issues - power prices and government incentives/regulation. It is very uncommon for people to invest in technologies where there isn't anything in it for them directly, either at a personal level or at a corporate level. We can make believe that all working together drives behaviour but it doesn't, it's all about incentives and return on investment.

If something is really important to us as a society it needs to be regulated and/or incentivised by government. My international colleagues working in this area tell me that this is a common thread throughout the energy efficiency industry.

stuzzo

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#665796 1-Aug-2012 23:23

Niel:
kiwitrc: Niel, what is Holmes Inspection?

http://www.mikeholmesinspections.com/
In Canada they lay plywood over the trusses and then shingles. Then the inside gets covered in spray foam insulation. Then a thick layer of insulation on the ceiling. But the ceiling space is still ventilated to keep it dry. Useful comment he often makes is that the house with less snow on the roof has poorer insulation.

Can't remember when it is on Living Channel, think it is Saturday night or maybe Friday night.

Bear in mind that, in Canada, building techniques are somewhat different than here because of the extremely cold temperatures.
Polythene is often put on the inside of walls as a vapour barrier but not favored in more temperate climates as half the year it is on the wrong side of the wall and can lead to mould.

I suspect ply on the roof is mainly for strength to cope with the weight of snow along with suiting the asphalt tiles that are commonly used.

Aredwood

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#669876 8-Aug-2012 23:34

Some things to ask the seller before buying any heatpump water heater.

Does it use the heatpump exclusively or does it use an electric element also? Some models use an element if the outside temp drops below 5degC and there are models that use the heatpump to heat the cylinder to 55deg and the element to boost the cylinder from 55 to 60 ounce per day.

What is the C.O.P. at different outdoor temps? Due to much larger temp rise that heatpump water heaters have to do compared to heatpump room heaters. Their C.O.P. will generally be lower. Also consider that the colder it is the more energy needed to heat your hot water. Due to colder incoming water temp and higher usage.

Consider putting a timer on your heatpump water heater so it only runs during the day and therefore has a better C.O.P. Also if you require hot water hotter than 55degC then generally heatpump water heaters won't be suitable. Although you could add gas or electric boost to get the required extra temp.

If you want to get one for purely environmental reasons think very carefully. There is a study on solar hot water heaters that concluded that bigger environmental benefits are gained by installing night rate electric cylinders compared to solar with electric boost. I assume heatpump water heaters will be similar. Can't post a link sorry since I am not allowed yet. (I am a new member).

stuzzo

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#669898 9-Aug-2012 04:53

I think this is the report you may be referring to from the Parliamentary Commissioner for the Environment.

http://www.pce.parliament.nz/assets/Uploads/Hot-Waterweb.pdf

It is more focussing on whether subsidizing solar hot water is good use of public money than whether it is environmentally friendly or not.

Jaxson

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#669914 9-Aug-2012 07:58

I'm also personally not that keen on external hot water cisterns. I quite like the idea of a hot water cupboard, so any heat losses at least come back into the house. I might be wrong, but it looks like a lot of these heat pump hot water systems are all located outside?

kiwitrc

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#669919 9-Aug-2012 08:14

Jaxson: I'm also personally not that keen on external hot water cisterns. I quite like the idea of a hot water cupboard, so any heat losses at least come back into the house. I might be wrong, but it looks like a lot of these heat pump hot water systems are all located outside?

Split ones are inside for the storage

Jaxson

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#669920 9-Aug-2012 08:20

kiwitrc:

Split ones are inside for the storage

Sweet, thanks.

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