Heat Pump Hot water

[Smurf]

I'm about to move house and suspect I may need to replace the water heater. At least that's what the building inspector suggested - it's working now but near the end of its life according to him. And of course when it fails it will be urgent - hence some research now.

No piped gas in the street and cylinders are over $100 each (45kg) so forget gas. Electricity's about to get quite a bit more expensive next year too so I'm interested in some sort of solar / heat pump system if it's affordable.

All the research I've done says that a heat pump will be better than conventional solar here (Tas) so that's what I've looked at so far.

Most of them seem to be "all in one" units and need to be installed outside. Given that I have a pretty large area under the house and that's where the existing electric water heater is, I'd prefer to have a "split system" with the tank inside and the fan etc outside. That's simply because I can think of better things to do with a patch of garden than sit a water heater on it.

Anyone know of or have experience with any suitable systems which can have the tank separate from the fan unit? They would only be a few metres apart. Also any info on the cost of the differnet systems?

[patty]

G'day Smurf I have just recently installed a Quantum Heat Pump 270 ltr Unit at my place for about 2 mnths now this is an all in one unit when i was initially looking around at the different types I am positive Quantum do a split unit check their website out just do a google on Quantum hot water

cheers

[Big Shed]

Friends of ours installed a Quantum in their new place. Thet are happy with its' performance, not quite so happy with the noise it makes.

[SilentButDeadly]

Whilst I think heatpumps are a good way to go there are a few useful options for gas too.

An alternative to bottled gas is to have a 200L(?) LPG tank buried in the garden then your gas supplier just comes around and tops it up as needed. Elgas provide this service where I am and the supply and install of the tank itself was a surprisingly cheap 'around $500'. Hooked up to an instantaneous hot water unti this'd be rather a good option (even better with a solar boost through evacuated glass collector)

[woodbe]

Hmm. We have an old electric off-peak water heater, that will probably dies in the next year or so.

It's costing about $1 a day to run

They don't say on the Quantum website, but it sounds like their units go on the normal power supply, which costs about 2.5 times as much as the off-peak.

Even accepting that the quantum will use 25% of the power as the old unit, a lot of that advantage goes out the window as soon as it goes onto standard rate power. In our case, we have:

Existing unit, 13Kwh/day = $95c offpeak
Quantum, 4Kw to heat one tank of water = $29c offpeak, but $71c at standard rate.

If the unit was attached to standard rate, it would probably cut in after every use and eat up the difference.

So, even though it is more efficient, and uses about 25% of the electricity, it would cost us about the same unless it can be connected to offpeak...

Anyone know?

woodbe.

[patty]

The Quantum unit Installed at our place is on offpeak 2 they recommend to run it for min 18 hrs a day I rang the energy supplier and found that offpeak 2 runs for a total of about 15 hrs in 2 different periods I took the chance with running it on off peak 2 and I have had no problems at all with it! Why are you still on Offpeak Woodbe Most HWS nowadays can sufficiently run on offpeak 2 cycles I just checked my electricity bill from last sept and I am only paying 7.9 cents per kilowatt hr the Quantum unit only uses electricity to drive a compressor the unit also does not have a booster element like many other heat pumps on the market

[patty]

Oh Smurf the Heat pump units are pricey we paid $2800 bucks
for our unit ouch but we got a $780 rebate from Quantum on the unit and if you combined family income is less than $100,000 bucks you also qualify for a $1,000 rebate from the goverment well in NSW you do not sure about Tasmania and other states so the unit has cost us about $1000 bucks

[woodbe]

patty,

We are still on offpeak because we didn't realise it was a bad idea :) Ours runs a couple of times a day, and we have no hotwater issues apart from the fact that when this one dies, we will have to go solar or heatpump. No town gas here.

Patty, you are getting ripped off. Our offpeak is 7.17c/kwh :D

Glad to hear that the heatpump units work ok on offpeak.

woodbe

[patty]

Patty, you are getting ripped off. Our offpeak is 7.17c/kwh :D
Well it use to be 7.32 cents and the bloody energy Authority jacked the prices up on both the general rate supply and the Offpeak supply the general rate use to be 10.8377 cents per kw hr now that has risen to 11.700 cent per hr dead set they are criminals the energy suppliers does not matter what it is Fuel for the car Gas or Electricity has all gone up they have us by the short and curlys I have not got my first bill since we installed the Quantum unit so it will be interesting!!

[woodbe]

patty,

Well, now I am getting ripped off :(

For standard power, we pay between 16.52 and 17.82 c/kwh. It's a sliding scale depending on use.

woodbe.

[patty]

Is that including the service availability charges? We pay 33.0000 cents per day for the service our last quarterly bill total usage was 2899.0kwh was $309.82 ex gst

[woodbe]

Yes, I think so.

On our whole bill, ex gst, the rate comes to average 16.4c/kwh

Patty: 10.7 cents/kwh
woodbe: 16.4 cents/kwh

Anyone else got a power bill handy to compare?

woodbe

[Smurf]

Took these prices straight from the Aurora (Tas electricity retailer) website.

Residential light & power
Supply charge 62.641 cents per day.
First 500kWh per quarter at 15.923c / kWh
Next 1000kWh at 15.153c / kWh
Remainder at 11.135c / kWh

Continuous space heating / hot water (locally known as "HydroHeat")
Supply charge 6.127c / day
All consumption 9.066c / kWh

Off peak with afternoon boost (9 hours at night, up to 5 hours afternoon)
Supply charge 13.298c / day
All consumption 6.96c / kWh

Off peak night only (up to 11 hours in one continuous period per day)
Supply charge 13.298c / day
All consumption 6.555c / kWh

Power is going up 15% or so in January and again in mid-2008. I'm told by a reaonably informed source that this is not planned to be a uniform 15% on everthing and that the heating / hot water tariffs are likely to go up considerably more than 15% with the light & power tariff not going up as much.

As for the heat pumps, does anyone know anything about the "Conergy" system? It can have the tank separate from the heat pump so looks attractive, at least in theory.

[patty]

Smurf did ya google quantum as i said in my irst blo i am sure they do a split unit i did see it I am not dreaming well at least i dont think I am pinch me will ya!

[Smurf]

Thanks for the info. I looked at Quantum and they do have a split heat pump system although it's a higher powered unit which suits up to 10 or so people. A bit bigger than I really need but depending on the cost it might work out.

Another one I found is the Siddons Solarstream. Siddons was the original company behind Quantum until they sold the business a few years ago.

One thing I hadn't realised is that practically all the conventional solar water heater manufacturers make split system solar units with the tank on the ground and panels on the roof. I thought there were only one or two of these systems on the market (and the ones I had heard about weren't too good) but it seems that there are plenty. Another option I'll have to check out.

[patty]

I have not got my first bill since we installed the Quantum unit so it will be interesting!!

Well today I got my first electricity bill after we had the hot water service installed and was absolutley shocked:o but in a great way:D
we have nearly halfed our electrcity bill seriously our last bill was $310.00 bucks the new bill $180.00 unbelievable:2tsup:<!-- / message -->

[bob w]

Hi smurf
I have only just read your thread so dont know if you have settled on a system yet. I see you are in Hobart, in which case I would suggest you research the suitability of the heat pump systems in your climate. I was involved in retailing HWS about 18months back and we were told that the heat pumps would not be sold to us as our climate was too cold and they couldn't guarantee their effectivness. (We are in the central west NSW with min temps of -5 to -10 deg C) This may have changed since then but it wouldn't hurt to check.
Cheers
Bob

[patty]

Well I would be surprised if the unit we have did not work to those levels ours is rated at -20 deg and as said before does not require a booster element like some of the others in the market!

[bob w]

Well I would be surprised if the unit we have did not work to those levels ours is rated at -20 deg and as said before does not require a booster element like some of the others in the market!

As I stated this was 18 months back so they have obviously rectified that shortfall. But at the time no manufacture would supply these units. Glad to hear you are happy with yours. It gives us options for when we are in need of a replacement unit.
Cheers
Bob

[elkangorito]

Back in 2003/4, I was a Facilities Manager for a few properties in Sydney. One of these properties was an upper class set of apartments in Balmain. These apartments had the earlier versions of the Quantum heat pumps. I will list my observations of the units at that time;

1] After 1 year, affected substantially by corrosion (close to salt water). They needed electrical & mechanical repairs to keep them functioning. Their IP rating was listed as 4x...not weatherproof. I hope that the newer Quantum units are at least weatherproof (IP55+).

2] In winter, the units could not supply enough hot water. This may have been a design fault (project engineering...nothing to do with Quantum) or it could have been as a result of cold weather. My boss, a refrigeration engineer with over 35 years of experience, told me that these units would only be effective & efficient at temperatures above zero degrees Celsius. Further, he said that R22 will be phased out, which means that the unit will not be able to develop a temperature as high as R22 could (condenser temp & pressure) than if R134a is used. This would result in an overall lower condenser temp for the same outside ambient temp & therefore a lower water temp. From what I have learnt, these units work very well in warmer climates & perform poorly in cold climates. Also, the "maintenance" factor needs to be considered.

[dan76]

hi it may be too late but i recently did a bit of warranty work on a rheem heat pump, and noticed on the label that under temps of 5 degrees it relied on the booster element to warm up.
might not suit a cold climate very well.

[mwalsh]

Hi smurf
I have only just read your thread so dont know if you have settled on a system yet. I see you are in Hobart, in which case I would suggest you research the suitability of the heat pump systems in your climate. I was involved in retailing HWS about 18months back and we were told that the heat pumps would not be sold to us as our climate was too cold and they couldn't guarantee their effectivness. (We are in the central west NSW with min temps of -5 to -10 deg C) This may have changed since then but it wouldn't hurt to check.
Cheers
Bob

You might try the Quantum unit, as it works down to -10oC

Cheers

Mark

[Smurf]

Thanks everyone.

I haven't needed to do anything about this yet, just wanted to be armed with the info for when the time comes.

I presently have an electric off-peak system that's still working. But I know that it's not in good condition. The anode was completely gone and lots of rust came out of the tank too. Filthy looking mud and water that looked like tea.

But I've replaced the anode and so far so good. It's in a location where if it blows up then it won't do any real damage. Just make a bit of a mess under the house and the water should get out under the roller door in the worst case.

So I'll leave it while it's working. Could be another 5 years if I'm lucky. Could blow in 5 minutes if I'm unlucky.

We had someone at work today quote on air-conditioning and they also do solar and heat pump HWS. He gave me a rough estimate of $2700 for an evacuated tube solar system and $2000 for a quantum heat pump. Both of those are after the various rebates etc. He also suggested that I wait if possible as apparently my local council is looking at some sort of incentive too - he suggested could be $500 or even $1000.

The latter would make a heat pump system not much more expensive to buy than an electric tank so very attractive.:U

[ScottM]

Just my 2c worth too...

I've got gas hot water nr Hobart, and yes, $100/bottle, which sounds expensive.

On the positive side each bottle lasts me 5 months for 1 person and also includes gas hotplates and gas BBQ running off this. Am sure it's about half the running price of electric for my particular usage....

Cheers