SolarPay News Feed
Benefits of heat pumps
Heat pumps are a great alternative to solar hot water systems with panels on the roof. The electricity savings are substantial (about 70% compared to 90% for a solar hot water system in Queensland). All solar rebates are available for a heat pump and the installation costs are substantially lower.
Heat pump advantages
Ingenero has selected our heat pumps on the basis of quality and energy efficiency.
Have limited space?
The Rheem MPi-325 can be placed against the wall of the house, making it a simple and straightforward replacement for an existing exterior electric hot water system. At around 1.6 metres tall, it has a two piece design which reduces its visibility to below most fencelines and minimises the distance over which its operating sound can be heard. Its back-up element ensures 60°C hot water in cold conditions and acts as an insurance policy against ever running out of hot water. Better still, it’s designed and manufactured in Australia and operates at only 45 decibels – the quietest heat pump around.
Need indoor operation?
Unlike most heat pumps, the Stiebel Eltron WWK300A is suitable for installation inside your home and is ideal for replacing existing internal hot water units in garages and laundry areas. Its sleek design and quiet operation ensure its versatility – the minimum room size required is 13m3.
The Stiebel Eltron can save up to 75% off your hot water energy bill. While this German designed and manufactured unit attracts the maximum number of RECs and draws the lowest power, it will operate on off-peak tariffs and timers, further reducing the cost of operation. It is also suitable for external installation, especially in frost-prone regions or coastal areas where corrosive salt is a problem.
How do heat pumps work?
Heat pumps use the same principle as a fridge, except the other way around. A fan draws in air and transfers its heat to refrigerant (gas) in an evaporator. The refrigerant is then compressed, further increasing its temperature, before it passes through a heat exchanger in the water tank where it transfers its heat to the water.
For details you can have a look at the wikipedia article on heat pumps.
Chian Choo, Casula
Heat pumps or solar hot water panels?
We used to recommend heat pumps only for situations where a solar hot water system was not feasible (e.g. too little sun or a roof that was too steep). However, the simpler installation reduces costs by up to $1,000. That makes it a very attractive alternative, not only to solar hot water systems with panels, but especially to the old electric systems.
Related Topics
- Solve your water heater problem with a heat pump
We are advocates of solar hot water, however sometimes solar isn’t an option. It could be that the roof isn’t suitable for panels, it faces the wrong direction or doesn’t...
November 21st, 2008 at 12:00 pm
[...] Benefits of Heat Pumps [...]
April 13th, 2009 at 5:31 am
Having just returned from holidays to find the old electric hot water unit in self destroy mode we now reqiure a suitable replacement. Could you give me the contact details of a supplier /installer in my area.
I am in North Nowra post code 2541
Thanks Col West
April 14th, 2009 at 7:26 pm
Hi Colin,
we look after Nowra as well. Just go through the online quoting process and you’ll get exact costs. We will then be in touch to confirm details and set a possible installation date.
Best regards
Alexander
May 6th, 2009 at 12:34 am
Good morning,
Can anyone tell me what are the disadvantages in having a heat pump to heat up water. I’ve heard that the water is not as hot as an off peak system.
Which brand is considered the best value.
Your advices would be appreciated.
Brian-Moorebank
May 6th, 2009 at 10:33 am
Hi Brian,
the biggest disadvantage is that it makes a slight noise. However with the new generation heat pumps, this is lower than many fridges.
Is the Water as Hot as an Electric Hot Water System
The water is definitely as hot as electric hot water systems. The only thing is that a tempering valve has to be installed. That tempering valve will reduce the temperature to 50 degrees Celsius and is thus cooler than what you might be used to from your electric system.
It is possible to run a separate (untempered) line to your kitchen and laundry. That water will come out at about 70 degrees Celsius.
Which Brand?
After researching the different manufacturers and speaking to many different plumbers, we have decided to go with the Dux Airoheat. It is one of the quietest and most efficient heat pumps on the market. It is manufactured in Australia and backed up by a good warranty.
We keep looking at new developments and should we feel another product is superior, we will start offering that.
Alexander
May 6th, 2009 at 11:28 am
Thanks Alexander,
Your advices are really appreciated-especially about hotter water to the kitchen for the dishwasher.
I am seriously considering using Off Peak 2 to heat up the water as my enquiries with Integral Energy reveal that a “pulse comes down the line” from 10-00pm to 7-00am then from 10-00am to 4-00pm at half the price of the “all day’ rate but approx 50% dearer than Off Peak 1 which only runs from 10-00pm to 7-00am. I feel the heat pump will need more electricity than that supplied by Off Peak 1.
Do you feel this is the way to go ? Regards, Brian-Moorebank
May 8th, 2009 at 11:18 am
Hi Brian,
heat pumps use a third of the electricity than electric hot water heaters.
I think the day rate is 16 cents, the off peak rate is 10 cents. So here is the yearly comparison:
3,000kWh for electric system off-peak (10c), cost: $300
1,000kWh for heat pump day rate (16c), cost: $160
So you’ve got a $140 saving each year for a heat pump. Over 10 years that really adds up. Depending on where you are, the rebates also make the heat pumps much cheaper than electric systems to put in.
Apart from financial considerations, the greenhouse gas emissions of heat pumps are also just a third of electric water heaters. So, to me the decision is absolutely for a heat pump. That’s why we are selling them, and governments are phasing out electric systems.
Alexander
May 10th, 2009 at 6:46 am
Thanks Alexander,
I need to know if the heat pump runs for 15 hours per day on Off Peak 2 will it be sufficient to have a good supply of hot water for 2 people ,or, should the heat pump work for 24 hours per day.
My “gut feeling” is that 15 hours per day will suffice-please advise.
Brian-Moorebank
May 13th, 2009 at 7:29 am
The heat pump only takes about 30 minutes to heat 50L of hot water (that is how much an average person – who is average? – uses per day. So no, it definitely should not run more than 2 or 3 hours. (In winter some more, in summer less as there is more warmth in the air).
The manufacturers specify to connect it to continuous tariff, but I do not know why, will ask our installation manager to comment.
May 13th, 2009 at 3:35 pm
Hi Brian,
It`s great to see you doing your homework regarding Heat Pumps, DUX advise to install their heat pumps on a continuous supply as they do not know where the system is installed and how it is to be used. For instance the geographical location could be Tasmania or Cairns, the draw down of hot water varies on the size of the household and of course how committed the household is to saving water and energy. Therefore DUX advise the safe harbour of a continuous supply.
However for up to 4 people I would say that you would be pretty safe on offpeak 2, you could try offpeak 1 and see how it goes but you may run out of hot water. On this basis I agree with your “gut feeling”.
Regarding the installation of a tempering valve, Australian plumbing regulations require that on all new system installations a tempering valve has to be installed for safety reasons, a supply can be taken off before the tempering valve and fed to the laundry and kitchen but NOT the bathrooms. The maximum temperature for this untempered supply will be 63 deg C controlled by the hot logic controller in the heat pump. Depending on access to your existing services this could be quite costly.
Brian, I hope this helps you to make a decision.
Paul Candy
May 23rd, 2009 at 1:05 pm
Thankyou Brian, I am having the same internal debate as yourself regarding the Dux Airoheat and you have asked the questions and received the answers I also need. Country Energy tell me to keep away from it if it requires continuous supply at 16c.
Alexander or Paul I also need to know why the unit has to be installed external to the dwelling? Doesn’t that decrease its longevity and in winter increase to requirement for the use of more electricity?
May 25th, 2009 at 12:51 pm
Hi Ronni,
All heat pumps are designed to be installed outside it is made of materials to withstand the conditions. It also expells cold air so needs to be installed where there is a constantly changing airmass in order for warm air to flow through the compressor have the heat extracted and be exhausted again.
May 26th, 2009 at 1:49 pm
Hi Alexander and Paul – the questions from Brian and your answers have helped me but to get my head around the off peak as opposed to continual supply I need to probe further.
I understand that innitally heating a tank of cold water takes up to 3 hours and the power it draws during that time is one third the power used to drive the standard electric HWH – so it uses less kilowatts over that time (and I guess this pretty much happens daily due to usage). I wonder then how long it is in downtime (using no power) before the thermostat will kick in to reheat up to set level again (50 to 60degree) – and I know ambient temperature will come into this but how often does it need to ‘top up’ the heat?.
I guess what I’m asking is whether it’s better to have the thermostat kick in whenever it needs to in order to maintain the heat and if that would cumulatively use less power than being on off peak and only heating at night but having to heat from a much lower degree as it’s lost heat by not topping up through the day – or been emptied by usage.
This is where off peak sounds wrong to me as my understanding is that it would need to maintain the temperature and avoid running down otherwise it needs more time each night to reheat, not to mention the fact that any usage means it’s then getting refilled with cold water and lowering the tanks temperature.
The other glaringly obvious point is that ambient heat is much higher during the day than at night so the sytem actually works best between midday and 2pm (same as solar). I have heard of someone using a timer so as to only heat during the hottest time of day – although this doesn’t allow the thermostat to kick in and top-up either.
Sorry for such a long post, please correct any misunderstandings on my part.
Many thanks
Giselle
May 26th, 2009 at 3:22 pm
Good points you are raising Gisselle, I guess it`s always a juggle between having the pump running longer at night when the air is cooler on a cheaper c/kw rate or shorter with a higer ambient temperature and higher c/kw cost. Of course personal usage comes into it, ie when is most of the hot water draw off in the evening or in the mornng? Not whithstanding this if the pump is being asked to work hard by a large family a continuous rate would be required especially if your are in the southern part of NSW.
Regards
Paul
May 29th, 2009 at 2:28 pm
Paul and Candy, I too have learnt a lot from these few questions from Gisselle, Ronni and Brian. We are considering putting in either ET solar or heat pumps. As we live in northern NSW with a fairly high ambient temperature most of the year, apart from the initial outlay I was wondering what are the pros and cons for both systems relevant to our situation. The salesman states that the position of our current HW system is perfect for both ET and heat pumps with a north east aspect. What are the long term savings for both systems? As our consideration is also based on environmental factors does the heat pumps have any adverse effect on the environment? I see you are recommending DUX Airoheat, how does this compare with Stiebel Eltron which our salesman has recommended?
June 1st, 2009 at 2:14 pm
Hi Ian,
environmentally, pure solar is always better than heat pumps. It saves a lot more electricity. Here are some figures on what you can save on electricity with solar systems. Heat pumps are always below that, by about 20-30% points.
So if your solar systems reduces electricity consumption by 85%, a heat pump reduces it by 55-65%.
Alexander
June 2nd, 2009 at 10:11 am
Hi,
We are interested in getting a heat pump..can you please suggest what capacity will be needed for a 4person household (lowset). Also about prices( including installation-with tamper valves etc)and rebates available?
Cheers
Subo
June 3rd, 2009 at 1:36 pm
Hi Subo, you can get a free instant quote by answering a few simple questions about your situation. It will also show you exactly which rebates are available for you.
Alexander
June 3rd, 2009 at 2:57 pm
Hi again and thanks for answers.
We’ve decided to go with the heat pump over solar hot water as we don’t have enough north facing roof space (the little we have may be used at a later date for solar power generation when we can afford it). Also solar hot water works most efficiently with a gas booster rather than electric and we don’t have access to gas.
As far as the heat pumps efficiency is concerned I’ll be testing it on continual power supply first and tracking the cost as well as how often the thermostat kicks in, duration etc. If I think it will save power and money by using a timer to regulate use then I’ll try that out to test effectiveness. Am guessing that in summer heating at night to use off peak rates will be best as it’s warm at night. But in winter would prefer to have it running during the day as it gets too cold at night. (We live near Newcastle NSW)
Regarding different systems (Hi Ian) I’ve looked long and hard at many different brands including the German made Stiebel Eltron – which is by all accounts a good unit. In fact they all are, Quantum (original in Aust), Skyline, Dux, Rheem (though some of the older units have had issues these have been addressed as the technology is over 30 years old. My decision ended up coming down to how loud these units are while running – as I have a neighbour close to the site as well as for our own ears. Most units have a decibel output of 50-51 and if you read user comments on http://www.productreview.com.au most complain about the noise level. My final choice came down to Dux Airoheat and Rheem MPi-325 – it was a difficult decision. Most of the way I had been leaning towards the Dux but the Rheem won me over due to 45 decibel rating.
Would be great if manufacturers had done this type of testing to give consumers the answers they’re looking for – a major selling point. There may be some info available but I’ve surfed the net extensively and read many opinions mostly from laypeople who may have had their heat pump for a few years and still don’t fully understand best applications.
Regards
Giselle
June 4th, 2009 at 10:37 am
I just stumbled across this thread whilst deliberating all the issues you’ve been discussing. It seems you’ve covered most things that I was investigating. I’m pretty much of the same opinion as Giselle and am leaning towards the Rheem MPi-325 for exactly the same reasons (so you’re not alone!). It’d be interesting to see how different people fair over the coming months (different tariffs, number of people in the household, locations) with their choices. I have a colleague who has just had a heat pump installed and he’s happy with it but has added that he would have preferred a quieter model. Again, I agree with Giselle, even the Rheem brochure doesn’t have figures on the sound levels of the products. It just compares them to “most domestic air-conditioners”. After all the noise is an environmental polution issue and goes hand-in-hand with the reduced carbon footprint.
Regards,
Ray
June 5th, 2009 at 9:21 am
Thanks Giselle for this excellent analysis. The only thing I’d like to know is where you found the decibel rating for the Rheem MPi-325.
I rang Rheem and their official line is that there is no decibel rating available, it is just “very quiet”.
Dux on the other hand, actually publish their decibel rating at 50dB. So I am wondering if the Rheem system were quieter than that, why wouldn’t they publish it.
The other consideration is efficiency. The best way to judge that is the REC value. 30 RECs for the Dux Airoheat, 27 REC’s for the Rheem MPi-325. That means 10% less efficiency (or 10% more electricity usage).
However, the Dux Airoheat is smaller (250L compared to 315L for the Rheem).
In all cases where we have sold the Dux Airoheat (even for families of 4) it produced enough hot water to satisfy everyone.
Alexander
June 5th, 2009 at 10:42 am
Hi Alexander
I too called Rheem and they told me the rating was 45 decibels (I hope I wasn’t mislead) I agree it should be published but have not found it anywhere including the owners manual. If anyone can please clarify it’s not too late for me to change.
I did take notice of the REC’s which is why I favoured Dux initially and still do but noise level was something I couldn’t ignore. I guess Rheem are affected by having the booster which will cut in when too cold to heat up the 100 litre reserve and also the power needed if frost builds up – where Dux have that covered better IMHO (I didn’t want the booster because I won’t need it and would be fine if water took a little longer to heat but mostly cos there’s only 2 of us).
So as much as the REC’s make it look less efficient I still think that comes down to location and ambient temps – I am hoping that my booster element never needs to kick in and will control that if need be by using a timer.
Regards
Giselle
June 8th, 2009 at 9:52 pm
Like others here, I too am considering a heat pump and I’m particularly interested in the sound levels of particular models because I’ve heard that some are as noisy as the ubiquitous a/c window rattler. Just a comment on decibels levels: For a decibel level to be meaningful, it needs to be quoted as to the distance at which the measurement was taken from the device. The standard is 1 metre, however, unscrupulus company’s may take the measurement from a further distance away and hence reduce the recorded value. i.e if the measurement is taken from 1km away then the reading will be zero!
Another way to fudge the figures is to not take the measurement in the noisiest plane. i.e. if most of the noise is emitted out the top of the device and the measurement is taken at a point horizontal to the device then this will be signifcantly lower. Another issue is that the sound measurements probably won’t be tested in a real world situation. i.e. they are probably tested in a large open space where as the worst case will be where the unit is located in a corner and with a low roof eave over the top. The walls and eaves are going to reflect a fair amount of noise. It also get’s even more complicated when you introduce weighting factors.
Sorry for the long diatribe but manufacturers aren’t going to do the best thing by consumers when they create their specifications and this particular one can be easily fudged. The only way to judge for yourself will be to observe one in operation yourself or seek others experience. Both of which I’m trying to do …
For what it’s worth, the outdoor unit on my 5kW reverse cycle heat pump is quoted as 62 decibels. I measured it at 1 metre, directly in front of the fan and it was 61 decibels. I don’t think it is overly noisy so I probably don’t have anything to worry about.
Regards, cc&c.
June 9th, 2009 at 4:04 pm
I’m after a split system for my circumstances which will mean I can put the tank on our enclosed verandah and the pump outside (on the other side of the wall). I am looking at Saxon (Sachs) and Siddon Solarstream. Does anyone know of any others? I want to make sure I have covered all options.
June 9th, 2009 at 4:09 pm
Just a further update, the Airoheat is 51 Decibels at 1.5 metres, which probably makes it around 56-58 decibels at 1 metre.
June 10th, 2009 at 11:41 am
I have a cautionary tale regarding running the Heat pumps on an Off Peak tariff. I had a Rheem MPI 325 installed about 2 months ago, running of the Off – Peak 2 tariff . All was going well until last week when we found we only had enough hotwater for 3 showers (3 persons having a shower each that is). I called Rheem who told us this was due to the shortening of the off peak period during colder times. So I would, contrary to what we were told by the installer recommend running it of the continuous supply.
Regarding Noise, I don’t know if it is a function of temperature, aging of the heat pump or increased sensitivity of my ears, but I’m sure our heat pump has become a little louder since it became colder. Not too loud, but may become annoying if installed near sleeping areas.
Regards,
Col.
June 11th, 2009 at 5:27 pm
In response to Jo-Anne, the heat pumps we currently sell at SolarPay (Dux) can’t be split, so we’re not able to offer you any advice on split systems. Good luck with that search.
Regarding off peak vs continuous, Dux recommends running their heat pumps on a continuous electricity supply, so Colin’s cautionary tale, above, supports Dux’s logic. They want to make sure their product works well for their customers, regardless of location, and running on a continuous supply is one way of ensuring that happens.
I can’t really comment on whether heat pumps get louder in cold weather. If people are concerned about noise, cc&c’s advice is spot on – find someone who’s got a heat pump, talk to them about it and listen to the noise it makes. A heat pump sounds much like a refrigerator and, like a refrigerator, it doesn’t run the whole time.
Ann
June 11th, 2009 at 8:14 pm
I had a Rheem MPI325 fitted just before christmas. All was going well until about 4 weeks ago when the night time temperatures started to drop below 10 degrees. We had limited hot water and I had quite a few cold showers as I am usually the last to shower each night. Several phone calls were made and the installer made a visit. Theses unit are made to be powered at ALL times which is a joke (we were told it will be fine to operate on off peak all year round). Where I live the power supply is PEAK or OFF PEAK 1.
Last night the temp dropped to -1 degrees. The hot water did not cut in until 10am and worked all day up until 7pm when it cut out on low ambient temp (it is 8 degrees outside and the boost element is kicked in). 2 kids bathed and 2 adults showered and the cold tap did not see much use for the last shower. I am very seriously considering disconnecting the unit and going back to a silent middle of the night off peak unit (the old one). Has anybody else had this problem because my installer thinks this is how the system is meant to work?????
Regards
Ben
June 18th, 2009 at 11:32 am
Hi,
I just installed a Rheem 325 Litre Tank. I live in Goulburn where temperatures get below 0 degrees at times. Plumber advised that the 325 heat pump was sufficient for our household, that is, two adults, two young children. Have had it installed and woke the next morning to have it run out quickly (never happened before with previous hot water system). After speaking to rheem rep and other plumbers in area, they advised that the 310 was the better option. Have just switched to off peak 2 (from off peak 1). Should this fix the problem, that is, water running out of water quickly? Would it be more expensive now though going from off peak 1 to off peak 2? I am just concerned now that I will have to work around the heat pump in that if i run out in the morning, then will have to wait for the other operating off peak hours to kick in before water can heat up again. Any help would be great.
Thanks
Courtnie
June 18th, 2009 at 4:32 pm
To all of you, err us.
I’ve just installed a Quantum 270l Heat Pump. I live in a moderate climate in Sysdney – night time temp rarely falls below 5 deg C. I am south facing and have large trees overshadowing all my roof for most of the day, so a heat pump was the only way to go.
I’ve had the untit for 2 weeks now. Heating performance so far is fine. Quantum claim that it will work down to – 10 deg C, but their published COP figure is then down to just over 1, i.e. no better than an electric element heater. But, it doesn’t (apparently) need a booster element and it has none either.
The Quantum uses an external spiral refrigiration coil wrapped around the hot water cylinder, so the water is heated more or less uniformly across top and bottom simultaneously.
Now, to the thing that vexes me most about this unit.
It’s the noise level. Quantum claim it to be no noiser than a 1hp aircon and have a stated 52 dBA noise rating. I don’t know how they get that as I measured 62 dBA at 1.5m. As the ambient temperature drops, it get a little less noisy, but still comes in at 60 dBA.
By comparison, my 5hP Daiken non-inverter 3 phase reverse cycle aircon is rated at 53 dBA and indeed it comes in at that at 1.5m.
If you look inisde the Quantum, you’ll see that there has been no attempt at all in acoustically quieting the compressor. It just sits there all by itself, just like the old window rattlers did.
So, it’s no wonder then, that the noise level is so high. Just a bit of effort in wrapping the compressor with some acoustic materila, would go a long way to reduce the noise I would think. It may need a couple of wraps of low pressure line to keep it cool when all wrapped up, but this should not prove an insurmountable job.
Until Quantum (and I expect others as well), realise that their market penetration would be so much better if they kept “a lid on the noise”, I feel that Heat Pump heaters will not get the acceptance they possibly deserve.
June 18th, 2009 at 5:01 pm
Just a comment too echoing previous discussions on whether to connect up to a full or continuous tarrif or one of the off-peak ones.
As some have already stated, the Coefficiency Of Performance (COP) of heat pumps drops off as the ambient temperature drops. Heat pumps work best when you least need them – when the indoor and outdoor temperatures are almost the same. So when the outside temperature drops to near zero, there is almost a 50 deg C difference between the water tank (indoor equiv) and the outside evaporator.
So, if you connect up to full off-peak tarrif, you only get power during midnight to very early morning and you’ll chew up almost as much power as a standard heating element and take nearly 3 times as long as a normal 4.8KW electric heater (heat pump output is typically only around 1KW at a COP of 1).
So, the running costs are really going to be the same as if you had remained on full off-peak and you are getting none of the benefits a heat pump can provide. On top of that, you’ll take up to 3 times or more longer to heat the same amount of water.
Contrast this with running the unit at the warmest part of the day, when you may typically get (in Sydney) a 15-20 deg C ambient temperature and a typical COP of 3.
With a ratio of full off-peak to standard continuous tarrif of 3 (in my case 5.15c/KWh to 15.25c/KWh)there is no difference in overall running cost between the 2 tarrifs.
Now, things change a bit in summer time and of course in warmer climates in general. If you never go much below 12-15 deg C, then a full off-peak tarrif should work out better – most units give a COP of between 2.5 and 3 for this temperature range (with humidity at least 60% or higher). You also need less time to heat a tank full of water, so you’re better off there as well and should have enough time to heat a full tank of cold water.
June 19th, 2009 at 4:18 pm
Hi Courtnie,
Thanks for your note. Rheem systems operate a little differently in that they have a back up element. In your case we would advise you go back to Rheem to ask what best suits that system in order for it to function at its optimum. In the same way we like to support our clients with their systems, Rheem would like to do the same.
What we can say is that with our heat pumps, we recommend that they are hooked up to continuous supply tariff, guaranteeing a constant supply of hot water. This does not mean that your heat pump will be continually chewing up electricity and costing you money on continuous supply – on the contrary, they utilise what’s called a ‘hot logic’ sensor that activates the use of electricity when needed.
Many of our clients have found that the quarterly fees payable for being on off-peak tariffs far outweigh the cost of electricity used by heat pump on continuous tariff.
June 19th, 2009 at 5:02 pm
Thank you Phil for your very informative post regarding heat pump efficiency in your experience. It certainly will assist others in their decision making process when considering installing a heat pump.
June 19th, 2009 at 5:04 pm
Response for Phil:
We prefer not to comment on Quantum systems as we do not sell them at this point in time. Also, I’m sure noise level varies from system to system. Our Dux subzero heat pumps are well known for their quiet operation and to date we have not received any complaints regarding noise levels.
June 24th, 2009 at 10:21 am
Wow, really great information here with respectful mention of competitive products – excellent.
Clearly noise and whether or not continuous power are required are the big factors.
The elephant in the room in all of these “replace what you have with a greener option” schemes is that there is a whole bunch of resources consumed (and hence carbon output) in the process of manufacturing the replacement device. So I wonder if things like RECs take this into consideration.
I have just used your instant quote page and it indicated that due to combined annual income we would not be eligible for the federal rebate. I am pretty sure that the $1600 rebate that is part of the stimulus package is not means tested, so as long as the insulation rebate has not been claimed the federal rebate is in fact available. This would mean that you are potentially turning customers off by significantly over-quoting the final cost.
I get the feeling that I may be better of waiting for a subsequent generation of heat pump models that take the noise levels another issues further into consideration. But I am certainly watching this space.
June 24th, 2009 at 10:29 am
Hi all – I’d like to express my thanks to the site administrators for having such a good response system and all contributors who’ve helped each other via comments (very helpful;-)
I had my heat pump installed 2 weeks ago and am very happy with it. We ended up with the Rheem but also liked the Dux. The sound level isn’t so bad but we don’t have it near a bedroom. We moved it to a new site rather than where the old one had been – it’s now very close to the kitchen so almost instant hot water through kitchen tap now which is great!! It’s on our deck so has open air to operate but warmer ambient area than on the ground where it gets very wet and cold – also tried to get it near morning sun.
I’ve come to the conclusion that it’s pretty much a false economy to try using it on off peak – as suggested above the fees for connecting to off peak outweigh the benefit. We have ours on continual supply and it’s really not running very often but it kicks in for short bursts to maintain the temp accross the whole 24hrs – we have not had it go cold yet. Manufacturers recommend continuous supply – installers are probably saying off peak is ok because the owner wants it that way and previously installed units were ok through summer months but not doing so well now it’s colder.
So I say don’t bother with off peak use the machine as it is intended to be used and you’ll have no complaints.
Cheers
Giselle
June 24th, 2009 at 12:33 pm
Thanks Giselle. Great to hear about your satisfaction with your heat pump and your appreciation of our free flow of information we have going via our blog here. We encourage everyone to throw in whatever comments or feedback they have based on their experiences with Solar Hot Water systems that may be useful for others in their decision making process. Heat pumps are brilliant in terms of how quickly they replenish their hot water – a good option for those without the full sun or difficult roof for installation of solar panels, and cheapest and easiest to install. Like you said in your case, positioning of the tank closest to where most hot water is used also makes a big difference.
June 24th, 2009 at 4:51 pm
Hi there Scott,
With regard to RECs, you can visit this website for detailed information: http://www.orer.gov.au/recs/index.html#what
That’s a good point you brought up about our instant quote system on our website.
The questions on the website are designed to give the correct rebates with as little client input as possible. You are absolutely right about getting the solar hot water rebate (also available for heat pumps), even with an income over $100,000.
There is one question: Is the dwelling owned by a State or Territory government? For some reason (and we have not yet worked out what it is), some people choose “Yes” as an answer. That disqualifies them from the federal solar hot water rebate. That happened in your case as well.
Our focus is on gaining the most important details about a client’s situation in order to be accurate with our proposal, suggesting what system would best suit your needs.
For anyone reading this who is in the market for a solar hot water system and currently comparing prices, be sure that you are comparing apples with apples. Find out if your quote includes installation, or any other extra costs that may not be obvious in the beginning.
Because of the time our solar consultants take in our question asking, we are able to give accurate quotes before inspection. We stick to our quotes (unless a client gives us wrong information). This is the level of commitment we have to our clients. We like to be clear, cover all bases, and keep our word.
July 21st, 2009 at 10:10 pm
Hi,
There are so many options I am still not sure which direction I should turn!!!!
I live near Bungendore in NSW and at times the temps plummet to -10c.
What is ultimately the best solution? Only electric and potentially solar electricity in the future.
1. Solar Panels and tank on roof
2. Solar Panels with tank at ground level
3. Heat Pump north side of house (better) or south side where my unit is currently located
4. Combination of a Heat pump on the ground (south) and a couple of solar panels on the roof.
My current two element electric hot water system is nearing its life and I would like to make one good decision that will not come back to haunt me in the future.
Any links or material would be welcomed.
Cheers
Phil
July 22nd, 2009 at 2:03 pm
Hi Phil
Your decision about whether to choose solar hot water or a heat pump sounds like it comes down to two things – your roof and your budget.
You need suitable roof space for solar panels facing an appropriate direction. North is ideal, other directions are less efficient, and south is not suitable. The panels should not be shaded by trees etc.
A solar system will be highly energy efficient, but in cold times it will most likely need electric boosting. How much boosting is determined by the number of people in the house using hot water (the more use, the more boosting, especially on dull days) and the weather patterns.
We don’t sell solar systems with tanks on the roof because we find many roofs aren’t suitable to take the weight of the unit. A split solar system might well allow you to put a new tank in the same spot as your old unit, saving on installation costs.
If you don’t have suitable roof space for panels, a heat pump is a great alternative and it’s also cheaper than solar. (Check out our online quoting system to compare prices). Their energy efficiency is very high, but not quite as high as solar. However they don’t need sunshine to work at peak efficiency. You are right though – north facing placement is better than south. South will work, but less efficiently and will need some boosting in your circumstances. The Rheem MPi-325 is the heat pump we would recommend for you as it has a booster element. If space permits, it may well simply replace your current electric unit but, again, moving it to the north side maximises efficiency and minimises operating costs but adds to installation costs.
There is no simple way of connecting solar panels to a heat pump, so we wouldn’t recommend it.
Both solar hot water and heat pumps attract federal and state rebates, so now is a great time to be switching over. Whichever you choose, you can expect to save up to 70% of the energy used to heat water in your home.
I would suggest a chat with one of our solar consultants would clarify the best choice, as they will ask a series of questions about space, layout, noise etc (freecall 1800 993 334). (Heat pumps are quiet but they do produce some noise, which should be considered as part of your decision).
Hope this helps.
August 4th, 2009 at 4:53 pm
Hi all,
Im confused on the way to go,either solar or heatpump.
By the way im having my dux airoheat removed ,poor performance ,12 repairs and 3 units so far in 12 weeks,refund request.
So im back to square 1.stiebel eltron seems to get a high performance rating on paper so i was wondering should i go heat pump again or solar?
Also checked on siddons unit ,skyline energy unit,edwards heatpump ,rheem,quantum and solarhart.
Its a mine field.
I live in the Campbelltown nsw area,a few icy mornings(dux couldnt cope).
Dont want to go the same mistake again.
HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Thanks
Peter
August 6th, 2009 at 10:14 am
Hi Peter
There are a number of variables to take into consideration when choosing firstly between heat pumps and solar hot water, and secondly deciding which particular unit is best for you. And some situations are more complex than others.
It could be that your home presents certain peculiarities that need to be factored into the equation, as well as the usual questions – what is the size, aspect and pitch of your roof, how much sunlight does it receive through the day, does it vary seasonally, how many people live in your home, do you have frequent visitors, what time of day do they make highest demands for hot water, and so on?
Our online quoting system goes some way towards working through these questions, however given your past challenges, it could be that an installer needs to take a look at your home before you make a decision. I suggest you complete an online quote on our site, then speak with a solar consultant. They may well send out an installer to take a look (in which case it won’t cost you anything).
Once you are armed with better information, you’ll be able to prioritise your needs and we will make a recommendation to you.
Hope this helps.
Ann
August 10th, 2009 at 7:03 pm
Hi Peter.
I really have enjoyed this site , plenty of concerns Answered. I have been looking at different brands and systems Re the heat pumps else where and was getting rather confused . and over loaded with it all . I suppose it must come down to the indavidual need and budget.
I am retired live in Port Macquarie nsw with just my husband and myself but also need to cater for other family members that visit during the holiday seasons. So any further advice would be appreciated
Thanks Pam
August 12th, 2009 at 3:32 pm
Hi Pam
Thanks for your comments about our website. We try to offer good quality information.
Re a heat pump that would suit your circumstances, any of our three heat pumps would meet your needs for enough hot water when visitors arrive. The big question for you perhaps is: where do you want to install it and what would you be replacing?
If you want to replace an indoor hot water system, then the Stiebel Eltron is the only one that will operate indoors. (It’s also German made and very good quality).
But if your system is outside, then there are a number of other factors to consider. If you want to talk to one of our solar consultants (free call 1800 993 334) they can step through your needs with you.
You are spot on: it pretty much comes down to individual needs and budget. Right now the rebates in NSW on solar hot water and heat pumps are excellent so the prices are very attractive.
Ann
August 16th, 2009 at 6:21 pm
Hi Pam,given the crap ive been thru id reccomend the Stiebel eltron or the siddons,anything else is a waste of time if you have guests or you mand hubby and 2 kids.Learnt by experience and other forums what is good and what is useless.
As Ann says the Stiebel is a wise choice,consider the Stiebel with the back up element or you can follow this link,http://forums.whirlpool.net.au/forum-replies.cfm?t=740793
August 16th, 2009 at 7:56 pm
I’ve had a Dux Airoheat heat pump installed for about 4 months and have had no problems so far. We had it connected to the continuous tariff. There’s only two of us in the house and we shower in the evening so the unit switches on at night either during the shower or just after. In winter this has meant that it has run for many hours in the middle of the night (single figure temps overnight – we live near Hornsby) and much longer than it did when we had it installed in April.
Due to the long running time of the unit at the coldest time of day, and the fact we are on a continuous tariff, I got a digital timer installed and I now allow it to run between 12pm-5pm each day. It usually runs about 3-4 hours (temps probably around 16-22C). I expect as we move towards summer it will run for shorter periods and will end up paying the same amount as my old hot water system while consuming a fraction of the electricity.
August 17th, 2009 at 9:06 pm
hi to all . I once was in the same decision making area as it seems many others are . with so many makes and systems , I found it very confusing . I decided on natural gas boosted solar , 2 panels only, on a north facing roof at a Newcastle suburb . Plenty of hot water . I checked the boost system at 6pm 4 days after installation while the shower was in use and found it ” boosting ” ie, USING GAS . so I turned the gas supply OFF .It was turned on again last week when it was cloudy and raining for one day as the water temp ran warm only then turned OFF again. It HAS NOT BEEN TURNED ON AGAIN . I am retired and there are only 2 people living in the house although my son was home from London for ten days and we always had PLENTY of hot water . At 7am the water temp is 50 degrees as set by the system .If the sun comes up at 6.30 it is heating the water until it goes down again for FREE , FREE , FREE .Hope this info is helpful ……… norm P S . I would imagine L P Gas would do the same job . ????????????
August 19th, 2009 at 7:33 am
I am so glad I found your site as I have been so worried about installing out Rheem heat pump. We were very happy with it and did some research and took some advice before getting one. Our daughter in Canberra decided to get one too but her husband googled “pros and cons of heat pumps” and the comments are so bad they cancelled their order. The Rheem only received a star rating of 2 out of 5 and we have been anxiously waiting our first electricity accounts.We hear very little noise and have a constant supply of good hot water.However a friend put one in 2 weeks before us and it has already broken down and for 2 weeks has been running on the booster( must be costing heaps) while waiting for a service man to come. Our local plumber said the Rheem rep. is hard to contact and the pros and cons column said Rheems service is non-existent.
August 19th, 2009 at 7:09 pm
[...] Heat Pumps [...]
August 20th, 2009 at 6:02 pm
I can see most people in here are 2+ maybe little ones, only people on heat pumps with 2 adults and minimum 2 teenagers should comment on heat pumps.
If I had 250 litre tank on off peak before and survived no probs with hot water ,then i can say the 250 litre dux airoheat cannot cope with 2 adults and 2 teenagers.
DUX CAN ONLY PROVIDE 60% of tank capacity 150 liters if the unit has just cycled off and nobody has drawn any water from the tank..
Good only for 2 people on the dux.
All those on dux heat pumps ,do a dump test and measure the amount of hotwater you receive ,you will be frightened that you have been conned into believing it will supply 250 litres…………
DO THE TEST
August 24th, 2009 at 10:28 am
Hi Peter
Any hot water system needs to meet the needs of the household, and needs can vary considerably.
Do you run your heat pump on night rate or continuous tariff?
If you hook up the heat pump to a night rate tariff, it means that regardless of how little or how much hot water you use through the day, the system won’t begin to heat the water until night. As the ambient temperature at night is cooler, it will take longer to heat the entire tank. Full recovery of a cold tank at night will take pretty much all night, depending on the air temperature.
The Dux heat pump is designed so you draw hot water from the top of the tank while it replenishes from the bottom. This design means it’s not a straightforward dilution of hot water with cold as you use the hot, however there has to be some mixing as the hot is used and the cold fills from the bottom. If you are on night rate and the use is happening during the day, the cooling of the tank water is more noticeable than if it was reheating as the water is used.
For all these reasons, Dux recommends heat pumps are connected to continuous tariff.
If you are already running on continuous tariff, it sounds like you need a larger capacity tank to meet your needs, or another type of system. Is solar an option for your household?
Ann
August 24th, 2009 at 12:41 pm
[...] Heat Pumps [...]
August 25th, 2009 at 6:44 pm
Hi All
Just thought I’d pop back to say that we’ve had our heat pump for over 2 months now and very happy with it.
Shirley I too saw all of the bad comments about the Rheem but get him to check the model they’re complaining about – the ones I saw were referring to the other older model. The feedback I found about the Rheem MPi-325 was all good and completely different to everything else I’d seen.
Peter I do only have 2 in our house but we’ve had another 2 adults plus 2 toddlers spend the weekend and had no problems. We did space our showers apart a bit the same as we had with the old HWS but there was no discernable difference. We do have it on continual power (off peak goes contrary to the design and how it performs best) – that was the biggest consideration for me before buying it.
Cheers Giselle
August 28th, 2009 at 7:23 pm
We are building in N Vic (temperature extremes -5 to 45 deg C)
we were thinking of hydronic heating for the house, but now we also have a 12 m lap pool and spa to consider. Can one heat pump do the whole lot? The pool is enclosed, and can be opened to the outside in summer using cafe style curtains. We will have a pool blanket and lid for the spa.
If so, what size heat pump, suppliers, any other info – I know we will probably need 3 phase power?
August 31st, 2009 at 2:57 pm
Hi Julia
We are unaware of any one heat pump that could do all the tasks you need, so you will probably have to address each need separately. We would suggest the Rheem MPi-325 heat pump for your general domestic hot water because it has a backup element to ensure you have enough hot water when the temperature drops below 0. However if you have appropriate roof space, you might want to consider solar hot water. All solar hot water systems have boosters so you won’t run out of hot water. Even though we don’t sell in your area, try keying in your circumstances on-line quote for solar hot water and heat pump to find out what it recommends for you. You might also want to investigate solar pool systems as they could save you money over the long run.
Re three phase power, our electrician tells me you will probably need it, depending on your energy supplier and household energy requirements.
Ann
October 21st, 2009 at 5:34 am
Great Site! Wish it found this a while ago.
Have had the Dux system installed for a full 3 months now, so have a power bill to compare.
Whilst our TOTAL consumption has reduced _marginally_ it’s all PEAK power which is 3 x times the cost of OFF PEAK, so even allowing for the price rise in electricity, we’re nearly $200 worse off for the quarter.
I HAVE to try PEAK2 because we can’t afford that level of extra spend over a full year. Living in Coffs, I reckon we’ll get away with it.
As for noise, yeah, it’s like a big air con unit, but it’s not on for long, and in winter when it works the hardest, we’ve got the windows closed. You get used to it. I remember when we bought a new fridge it woke me up the first few nights… but after a while, it’s negligible.
October 22nd, 2009 at 9:21 am
Hi Rich
Thanks for your comments. We try very hard to offer good information here. By all means try off peak 2 for your heat pump. While Dux recommends hooking it up to continuous, off peak 2 could work for you. Living in the warmer climate of Coffs Harbour helps – also if the unit is in a warm spot, certainly not on the south side of the house, will help make the combination of off peak 2 and heat pump work well. The other important factor in this equation is the amount of hot water your household use and at what time of day they use it. If you have a high demand household, e.g. teenagers taking long showers, it will work against you.
All the best with it.
Ann
October 22nd, 2009 at 8:24 pm
Thanks Ann.
It’s on the north side, and gets morning sun… so… Got the sparky to switch it over to OP2. Will report back in 3 months on the saving!
In the meantime though, we certainly haven’t run out of hot water with a bath for 2 kids and showers for us so OP2 might just be OK.
REALLY HAPPY with the Dux on every other count!
Good luck guys, and don’t be scared to give the heat pumps a go!
Rich
October 27th, 2009 at 9:12 pm
My heat pump runs after the shortest of showers, or smallest load of washing. It runs for a long time. 6 hours per day is quite common, even with outside temperatures in the mid 20’s. Some days it is more like 8 hours. It also operates in the early hours when there is no hot water usage.
The Unit draws well over 1kW and the manufacturer says that this is all quite normal and that I have unrealistic expectations.
I estimate that it is using 2 – 3 times the power that it should.
Any comments?
October 28th, 2009 at 6:16 pm
Hi Aldo
Thanks for your question. It’s difficult for us to comment without knowing more: what kind of heat pump is it? What claims do the manufacturers make about its operation, and what is the warranty?
In very cold climates heat pumps will operate for longer periods of time. They also will turn on briefly if the temperature is very low to prevent damage to the unit. Where are you located? And because the water in the tank is mixing, they can turn on occasionally even if there no apparent draw-off of water.
Generally heat pumps are rated between at 0.8 kw to 2.2kw, so yours using 1kW is reasonable.
Ann
October 29th, 2009 at 7:17 pm
Hi,
Very informative website!
I had a Dux Aeroheat pump installed about 2 months ago (don’t hold your breath waiting for the government rebates!!) and am in a similar situation to Dave (comment 46). I was wondering if you could provide a comment on the electronic timer he mentioned. It’s something I’ve tried to look into further but when I have mentioned it to a few electricians I have been met with blank stares. How easy is it to install a timer into a Aeroheat pump, is it something any good electrician should know about, and do you think it would affect the overall running of the system, as I guess a timer stops it from running the way it was designed to run?
Cheers,
John
November 3rd, 2009 at 10:39 am
Does anyone have any experience of the effect of power loss due to storm damage or other grid supply problems on hot water supply vs Solar units? I am in an area where there are frequent violent electrical storms and subject to cyclones. Also, what ongoing maintenance costs are there regarding re-gassing of the R134a, which would need to be done on-site.
November 3rd, 2009 at 4:44 pm
Hi John
Dave (comment 46) has delayed his heat pump from starting up till the warmest part of the day so it will run at its most efficient and therefore economical. He can get away with this as they are only a two- person household.
Our installation manager (who is an electrician) says putting a timer onto a heat pump is an easy task for an electrician.
The timer needs to be placed in series with the supply to switch the power off to the heat pump when you don`t want it to run, much the same as a pool pump timer. It will not harm the unit in any way.
Hope this helps.
Ann
November 3rd, 2009 at 5:02 pm
Hi Rick
A split solar hot water system (panels on the roof, tank on the ground) requires electricity to move the water up to the panels and back to the tank. So if power is out for a long time, you will eventually run out of hot water. However, a close coupled system (ie tank on the roof) doesn’t need to pump the water to the roof, so may be a better choice for you if you are concerned about very long power outages.
As far as regassing a heat pump goes, we expect their regassing requirements would be similar to air conditioning units – i.e. a fairly straightforward procedure that wouldn’t need to happen very often, if at all.
Ann
December 4th, 2009 at 3:22 pm
Hi, I have a Solahart 300L close coupled solar system , installed in March 2006.
Have not used any electricity yet, I live in Eastern Suburbs in Brisbane.
I considered a heatpump system before deciding on the Solahart.
A couple of things swayed me, close coupled solar is unaffected by any power outages, and no motors or moving parts.
Another thing I found , which would also apply if you have a heatpump and are replacing a electric unit on offpeak power, you save the service fee ( can be up to $20 mo) by eliminating the extra meter.
December 6th, 2009 at 9:36 pm
We have a smart meter. Rates are 32.4 – peak,12.8 – shoulder and 7.4 off peak. Off peak 2 – 10.2. What effect will continuous power of heat pump have?
December 8th, 2009 at 5:46 am
Interesting thread – we are in Townsville and considering a heat pump vs solar. We have a western wall to put it on but it would be close to bedrooms. I think we might try to find a display home with one installed so we can have a listen to how loud they are. Our controlled supply consists of off for about 1.5 hours each morning and evening and ambient temp shouldn’t really be an issue here
Scott
December 10th, 2009 at 12:42 pm
Matt, it sounds like your system is working well for you. Well done. We don’t sell on-roof tanks because of the associated issues with making sure the roof can take the weight – they can weigh as much as 500kg. The right hot water system is the one that best meets the needs of the home and occupants.
Ann
December 10th, 2009 at 1:06 pm
John, Re your question about smart meters and heat pumps, if I understand your situation correctly, your smart meter gives you four different rates for your electricity depending on the time of day that you use your electricity/hot water. A heat pump used during the highest rate period will mean the savings in energy will be offset by paying a higher price for that energy. In this case, you could put a timer on the heat pump to prevent it coming on during the highest tariff times (an electrician needs to do this). Alternatively, your usage patterns for hot water might mean it’s not a problem and you get the cheap rate anyway.
Ann
December 10th, 2009 at 1:16 pm
Hi Scott, Your off peak 2 electricity rate is very suitable for a heat pump, especially in the heat of Townsville. Great idea to find a heat pump and experience first hand the sound it makes. The Rheem MPi-325 heat pump can be set up to face the fan away from a bedroom if you think it’s an issue. Also, it is the quietest on the market. However depending on your hot water usage patterns and the fact that you are on off peak 2, the unit might not need to switch on during the night, so sound levels might be a non-issue. Also, you could fit the heat pump with a timer so it doesn’t come on during sleeping times.
Ann
December 10th, 2009 at 8:48 pm
I’m actually getting a little worried – have read plenty of reviews that are really bad re Dux, Rheem, Quantum, Saxon. The only good reviews that I have found are for Stiebel units – hmmm, need to think this through some more.
Scott
December 15th, 2009 at 4:44 pm
Hi Scott,
One of the reasons people use these forums is to iron out problems, and people are more willing to be proactive about sharing negative stories compared with positive experiences. We have chosen to sell Stiebel, Rheem and Dux heat pumps because they are all very good quality systems, attracting a good number of RECs, and each offers particular advantages. Between them people will find one that meets their needs. For people to be happy with their heat pump, it needs to have been selected to fit with their particular situation. My suggestion is that you call us on freecall 1800 993 336 ext 301 and ask for Bruce. He’s one of our solar consultants and is very experienced in choosing the right heat pump – he’s also a plumber.
Ann
February 7th, 2010 at 4:22 pm
About 3 years ago, my standard electric hot water system was on the way out and I decided to go solar roof panels. However while researching I discovered Quantum solar heat pumps and after doing many, many hours of research both online and in person with many reps from different hot water tank suppliers. I decided on the 270 litre quantum solar heat pump system as they were the original company that put the heat pump technology into a domestic hot water system, since then the bigger companies are trying to copy it, however they cant get it as good. The Quantum does not need to “de ice” like the others for a start and it just looks like a better quality product. It was easily installed and it has been 3 years now of absolutely no issues whatsoever. I live at East Kurrajong which can be very harsh conditions, frosty below zero in the winter mornings all the way up to 45 degrees in the summer afternoons. We have never run out of hot water and yes it makes some noise but no worse than my air con. unit right next to it, besides it might only come on 3 times a day for an hour at a time anyway. Our electricty bill was reduced from 18kwh/day down to 12kwh/day. It is THE BEST decision I ever made and I have recomended them to others who have also had similar experience. Solar heat pumps I believe are the future and I can not fault Quantum.
February 9th, 2010 at 2:59 pm
Thanks Brent for your posting. You have obviously done your research and it’s great that you found a system that you are happy with. While we don’t sell the brand you chose, we believe we offer some very good heat pumps that between them will meet the needs of most people and give them a good return on their investment.
February 22nd, 2010 at 2:44 pm
We are in the process of building a new home and have been reading about heat pumps.The bulding company supplies a Rheem Integrity 24 gas hot water unit with house and i was wondering would a heat pump unit be more efficient ,would it be cheaper to run and is the initial cost difference between the two units significant if i was to pay the difference….Cheers
February 22nd, 2010 at 5:07 pm
Hi Peter
This page from the WA Government shows comparisons in running costs from the various hot water systems.
Ann
February 27th, 2010 at 3:37 pm
I had a 264-SS Heat Pump supplied and installed by Skyline Energy about 12 months and I am very happy with it. I would recommend anyone considering changing over to solar hot water to seriously consider heat pumps. I live in the hills about an hour out of Melbourne and winters can get pretty chilly but my heat pump can extract warmth from the surrounding air even on the chilliest days. This is the one major advantage heat pumps have over solar panels. Solar panels only work when the sun is out but heat pumps work both day and night. Cheers.