Heatpump efficiency Vs purchase cost.

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Aredwood

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#229085 7-Feb-2018 01:58

Does anyone know of a website or list of heatpump models available in NZ that is ordered by energy efficiency? The EECA website used to have this, but I can't find it now.

I want to get a heatpump, and want to calculate if buying a more efficient one will save enough on running costs to recover the extra purchase cost.

So far all of my searches turn up mostly marketing fluff.

Suckerpunch

124 posts

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#1952737 7-Feb-2018 07:11

Sorry I don't know a website that does the comparisons for you.

I ended up doing all the calculations myself based off information from a website.

This is the website I used...

https://www.temperzone.co.nz/FAQ/Understanding-Efficiency/

The calculation for energy consumption is basically...Heating required / COP x Running hours x Electricity cost.

Hope that's something of use.

Phil.

timmmay

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#1952760 7-Feb-2018 08:28

Interested in your results. Also factor in the high output so you can heat up quickly.

If you're only concerned with heating you could use smaller heaters and leave them on all the time. Even with heat pumps that tends to make my house more comfortable, I guess as it heats the house through. With heat pumps we do 5am to 9pm heating, with smaller heaters you might have to leave them on 24/7.

Advantage of other types of heaters is they may be less noisy.

Batman

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#1952815 7-Feb-2018 10:18

I think (that's just a guess) that the cost is at least neutral/equal.

At best you will almost definitely (also a guess) save money if you use the heat pump often enough.

Obviously if you never use the oil heater and after installing a heatpump, never uses the heat pump then it will be a big cost.

I have heard how much it costs to buy fuel for fires (bottled gas only in Dunedin, wood, pellet etc).

We have heatpumps in all our rooms that we run overnight during winter, and heatpumps in lounge that we run during the day (Dunedin) and our power bill in summer ~$200/mth and winter 300-400/mth. Basically we use heatpumps whenever we feel like it. Even in summer. Air conditioning. etc. That's not including other things like hot water, dryer, dishwasher (that uses electric heating elements).

Gordy7

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#1952870 7-Feb-2018 12:03

Not sure if there is a maintenance factor to consider also as part of the overall heat pump costs.

House I bought about 3 years ago had a Fujitsu heat pump installed (with filter screens) back about 2001.

Ran the compressed air through the indoor wall unit and blew out large wads of dust.

Also ran blew out the fins in the outdoor unit and removed spider webs and leaves.

I am sure the heating power bill dropped significantly.

Gordy

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timmmay

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#1952914 7-Feb-2018 13:07

Heat pump manuals say to clean the filters, none seem to say "pay a firm $100 a year to do sod all".

I watched them once, the hosed the outdoor unit and cleaned the filters. Also measured the temp of the heater, if it was too low they'd have charged us to fix it.

I haven't bothered getting my heat pumps serviced since. Oldest is Daikin, ten years old, been moved once, works great still.

Wash

57 posts

Master Geek

#1953617 8-Feb-2018 13:30

timmmay: Heat pump manuals say to clean the filters, none seem to say "pay a firm $100 a year to do sod all".

I watched them once, the hosed the outdoor unit and cleaned the filters. Also measured the temp of the heater, if it was too low they'd have charged us to fix it.

I haven't bothered getting my heat pumps serviced since. Oldest is Daikin, ten years old, been moved once, works great still.

From personal experience, cleaning the filters isn't sufficient. The indoor unit is a breeding ground for mold because when the heatpump is being used to heat, it is a warm damp enclosed space.

Whenever I've had someone in to service a heatpump, they've attached a large plastic bag beneath the indoor unit and flushed it out with a cleaning solution. The water that gets collected in the bag is invariably murky and dark coloured.

timmmay

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#1953668 8-Feb-2018 14:35

I saw them spray it with a cleaner once, but nothing like that. I vacuum that part as best I can m

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lapimate

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#1953730 8-Feb-2018 16:39

Gordy7: Not sure if there is a maintenance factor to consider also as part of the overall heat pump costs.

And depreciation and opportunity cost?

Stan

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#1953758 8-Feb-2018 17:37

There is also there heating efficiency at lower temperatures kinda harder to work out as many manufactures don't release the information, I would personally suggest something running R32 refrigerant as this is replacing r410a and it tends to be better at lower temperatures from the data I had when I was working in the industry.