Heat Pumps

[Perry]

It's just some tenants need some education on how to use heat pumps efficiently.

Goodness - why stop there? Add education on opening windows; leaving shower curtain fully extended after use; not putting small pots on large elements. The list goes on and on and on and . . . .

[sidinz]

I'm installing a heat pump in a holiday rental. Is there some way to 'lock' the temperature it will heat to? Don't want the people who stay there racking up $600 power bills by ramping it up to 30deg and opening all the windows.

[Learning]

I'm installing a heat pump in a holiday rental. Is there some way to 'lock' the temperature it will heat to? Don't want the people who stay there racking up $600 power bills by ramping it up to 30deg and opening all the windows.

The same 'lock' that would stop them doing the same for any appliance or heat source. 'Common sense'. Unfortunately the only thing common about common sense is that it's not common.

If you're that worried add a 'house rule' to you rental listing that renters pay for the electricity they use and make a note of meter readings between each let.

[sidinz]

If you're that worried add a 'house rule' to you rental listing that renters pay for the electricity they use and make a note of meter readings between each let.

I wish. Unfortunately, it's just not workable. A 'parental lock' would have been awesome. Because judging what I've found today, inspecting my property, holiday renters are indeed children.

[Bob Kane]

You are supposed to include the electricity use into the rent you charge.
Expect them to have the heat pump on high with the windows open.
Calculate what that would cost per day - include it in their daily charge.

[sidinz]

Calculate what that would cost per day - include it in their daily charge.

Do you know where I could find that information?

[Bob Kane]

Look at how much power the heatpump uses eg 2kw model or 3 kw?
Find the cost per unit from your electricity supplier - maybe 30c per unit?
Let's pretend 3 kw heatpump and 30c unit = 90 cents per hour.
1 day = 90c * 24 = $21.60 per day if used non-stop all day.

[Davo36]

Look at how much power the heatpump uses eg 2kw model or 3 kw?
Find the cost per unit from your electricity supplier - maybe 30c per unit?
Let's pretend 3 kw heatpump and 30c unit = 90 cents per hour.
1 day = 90c * 24 = $21.60 per day if used non-stop all day.

Is that correct? Doesn't it depend on the temperatures inside and outside?

It would only be fully on if it were raising cold air from outside to warm up a fairly cold room upstairs (or vice versa in summer) and once it got up to temperature, it'd slow right down, right?

[Bob Kane]

Keep up, Dave.
The person is worried about how much it will cost to run a heat pump when the tenant runs it on full power with the windows open - worst case - 24 hrs day.
I've just shown her how to calculate that.

[gusCF]

When we first bought our 15 y.o. house we used a couple of gas heaters and an intermittent oil column heater and it used to get a significant amount of condensation on cold Winter mornings. After buying two heat pumps the condensation dropped right down, however on colder mornings I'd probably still have enough condensation on the upper floor to soak up in a small bath towel and if it's really cold a little bit downstairs. I am toying with the idea of trying to eliminate the last of the condensation and I wonder if a dehumidifier on the top floor (the main condensate is on the bedroom windows) might remove most of the remaining moisture. It would be cheaper than buying a large balanced pressure system for a 6oo sq.m. house to make marginal gains. Is anyone in the same situation?

[sidinz]

Look at how much power the heatpump uses eg 2kw model or 3 kw?
Find the cost per unit from your electricity supplier - maybe 30c per unit?
Let's pretend 3 kw heatpump and 30c unit = 90 cents per hour.
1 day = 90c * 24 = $21.60 per day if used non-stop all day.

Gulp.......

[BlueSky]

we are really behind on our smart meters in NZ. There is nothing "smart" about them.
With the advances of technology i would have thought this would be more in line with "energy savings" and the green earth?

wait, most of the energy companies are focusing on renewable energy

[JABlog]

The unit I chose was the Mitsubishi as per my 1st thread.

Below are the usage costs.

MSZ-GE50VAD2 1.65 KW $2.14 per day $14.97 week $64.15 month 8 hr usage

http://www.mitsubishi-electric.co.nz/materials/Aircon/Energy_Usage_Costs/Domestic%20Heat%20Pump%20Energy%20Usage%202017-Jan.pdf

The running costs are far cheaper than say running a fan heater for at least 3-6 hours per day.

[ivanp]

The usage cost per hour depends on outside temperature isn't it?

[Learning]

The usage cost per hour depends on outside temperature isn't it?

Only when you're getting below zero temperatures outside and it would only be a small change in efficiency. Till you get to around -10 or so then the heatpumps starts struggling.