Any feedback re Saxon HW Heat Pumps & RECs? « Alternative Technology Assn Forums

Alternative Technology Assn Forums » Energy

Any feedback re Saxon HW Heat Pumps & RECs?

(35 posts) (11 voices)

Started 2 years ago by ec175
Latest reply from Sandman

Tags:

12 Next »

ec175
Member

Hi all,
I am about to replace my existing elec HW system (dual element 315 Rheem) and have been reviewing the available options taking into account the government rebates presently available. The Saxon seems to be a good choice for us based on :
- high number of available RECs - 38 for 400L model 6420 gives low out of pocket cost
- reasonably cheap installation is being offered
- Noise level is about average but with unit on ground may be less noticeable than the units at head height
- Copper tank with heat exchange coils inside?
- large tank capacity allows better buffer if off peak tariffs in use
- possible negative - this unit may have more variation in outlet temperature due smaller volume of water in "coil" (perhaps an issue in showers unless tempering valve fitted at additional cost).

I called Saxon to try and find out how long these units have been in production and they advised that they were introduced in around 2004 so I guess that any bugs or reliability issues should be known by now?

I have also had a look around to see if I can locate any performance graphs of comparisons (as you can find for Stiebel or Quantum)however I can not find any measure of efficiency beyond the high REC value attributed by the government rating agency. I presume that the high REC value implies high efficiency?

I was also informed that the RECs created will continue to be worth $42 up until around October (they may drop in value after this was the story) and would be interested in any comments you might have on this as I am considering placing an order in the next day or two.

Any comments or observations would be much appreciated.

Posted Thursday 23 Jul 2009 @ 9:34:08 am from IP #
Sunshine
Member

ec175,

I'd be very wary choosing a HWS just by the highest REC value.
The highest REC does not necessarily mean the lowest running cost.
I have a Hills Evacuated 30 tube 315 litre system with stainless steel tank. System is rated at 32 RECS, has been now installed for over 9 months, and operating cost has been zero (no electric boost required).
So in comparison a solar heat pump unit running for 9 months would still use a considerable amount of electricity.
We have a family of 3, the system recommended to us was a 22 tube 250 litre model, but I decided to upsize to the larger model (cost was around $600 extra), and it would mean boosting would not most likely not be necessary.
This theory of mine seems to be holding true. So therefore the REC value may not always give a true indication of system efficiency or running cost.
Obviously, when all the hot water systems were tested for REC certification, they must have deemed that all solar hot water systems need boosting. This is not true, as a simple upsize will normally mean zero ( or very rare) boosting is required, hence the REC value should indeed be higher than those systems which require electricity to run.

I note the Saxon system has a copper tank, so it won't last as long as a stainless tank.

Posted Thursday 23 Jul 2009 @ 11:50:45 am from IP #
ec175
Member

Sunshine,
You make a good point re the RECs. I probably should have added that I have a master plan to add an evacuated tube sytem in future as a pre-heater" (280 L stainless, 24 "wet tube" 2M x 58mm, copper coil heat exchange type around $1295 from QLD vendor) which I expect will provide most of our normal use in Sydney. This will leave the heat pump system to provide a pretty efficient (and cost effective) boost capacity and the total storage capacity of hot water will in itself help with short periods of dull weather. Total cost will ultimately be between $1500 and $2000 I imagine but I guess that this would compare favourably with the out of pocket on the Hills 30 tube / 315 with some other benfits in our situation.

I do have some experience with your system as well as I installed one at work last year and have been pretty happy with the results. It replaced a 315 litre Rheem with 3 x 4.8 KW elements on a ring main supplying our offices and hangar. I did make a few other changes to the system as well as it was horribly wasteful as originally setup > 12 years ago (minimal insulation, 3 speed circ pump on max speed running 24hours unecessarily etc).

On the copper tank thing, I was rather hoping that the tank will have quite a long life as it does not have a flow going through it (less build up of minerals etc?) as the water for the house just goes through the copper tube coil which should last a fair while with Sydney water quality(?). I also intend to use a 500 kPa pressure limiting valve which whould keep the stress reasonably low on the tank compared with leaving on mains pressure which it is rated for (up to 1100 kPa without pressure limiting according to install manual) There is no doubt that the tank supplied with the Hills unit is a nice one though.

Really grateful for the comments as it is always good to have another take on the idea as there are so many options!

Posted Thursday 23 Jul 2009 @ 1:10:23 pm from IP #
sun2steam
Member

ec175, I am a solar dealer at the Central Coast and I should be able to offer you the 'Queensland system' at least at lower transport cost to Sydney. Just drop me an email if you are interested.

sunshine, What you say is correct. it is possible to run a solar hot water system essentially without boosting, especially if it is over designed. However this is not according to the law because hot water systems must be heated once per day to 60C in order to prevent Legionella bacteria from growing. However I don't know if this is also true for the system that ec175 describes. The copper pipe has such a small volume that even under stagnant conditions not much bio-growth could happen.

Posted Thursday 23 Jul 2009 @ 1:51:31 pm from IP #
ec175
Member

sun2steam,
May well take you up on your offer. The unit is question is the "Sunergy" brand or similar correct? I can't really see the Legionella risk being high based on the plan in question as the heat pump tank should be able to be maintained at 60 deg with quite a low amount of heating (not none its true) I would think if the evac tube system is pre-heating the water. I can quite easily set up a logger to monitor the system once it is up and running in any case just to be on the safe side. One question re that system, are the tubes similarly hail resistant to the heat pipe style? The ramifications of hail breaking both inner and out tubes are a bit more catastrophic with 280 litres of water able to exit a large hole. That said, we are yet to experience any hail more than 10mm in size at our place since we have been here (>5 years now).

Posted Thursday 23 Jul 2009 @ 2:14:39 pm from IP #
rockabye
Member

I'm interested in upgrading my quantum heatpump 270l to solar assisted so the Sunergy system you mention sounds interesting. My average daily use from the heatpump is 3.5kWh/day, 2kWh/day summer and 6kWh/day in winter. So in cooler climates, we are lat 23degS, expect higher numbers.

Posted Thursday 23 Jul 2009 @ 8:58:36 pm from IP #
Sunshine
Member

sun2steam,

The solar hot water system storage temperature does reach at least 60 degrees each day no problem.
I have never had so much piping hot water, compared with the storage gas system we had before.
The system is designed to store water at up to 95 degrees, so achieving 60 degree temperature is not a problem.

Posted Thursday 23 Jul 2009 @ 11:09:45 pm from IP #
ec175
Member

Sunshine,

What general area are you in and are you near the coast? Certainly the performance of your system is quite impressive however I am not sure that my household of four with two teenagers are not a bit harder on the hot water than is ideal.

Posted Friday 24 Jul 2009 @ 8:27:17 am from IP #
Sunshine
Member

ec175,

I live in Brisbane.
A friend of mine has a Beazley flat panel solar HWS, also in Brisbane with a family of 3, and they reasonably regularly need to boost, a day or two of cloud or rain for them requires boosting.
Yes, it depends obviously on the amount of hot water being used in the house, but we really enjoy our hot showers, spas or bath in winter (don't we all!)
I even connected the dishwasher to hot water as well, to reduce power usage, as the machine doesn't need to heat the water anymore, and the extra 22 litres of hot water hasn't impacted on the system.
To be honest, the system isn't really positioned in an ideal position either, it is on a rather steep western roofline.
If it was facing north it would perform even better.
I had to install it facing west, as I have a 3kW solar PV system which uses all of my northern facing roof.
For your household (not sure where you live), I would go for the 40 tube/315 litre system.
We had a 170 litre gas storage system beforehand which would always run out of hot water after filling the spa about 3/4 full, which was not very nice.

Posted Friday 24 Jul 2009 @ 1:03:57 pm from IP #
Solgen
Member

A couple of things to consider:
- Heat pumps are fantastic when the water is cold but as the water heats up the efficiency quickly drops off due to the temp differential between the hot gas off the compressor and the water gets becoming smaller. Consequently, if it can be arranged,a more efficient arrangement would be a heat pump pre heating a solar system rather than the reverse.

- Like Sunshine I have a 315l, 40 tube system but live in Sydney in a 2 person household. So far during winter I have had to turn on the boost for 10 days in total, generally this was after a 4-5 days of cloudy/rainy weather. Overall I am very happy with the system but the tank has not got above 50 deg during winter except when I boost it. Therefore, I am putting myself at a slight risk of legionella. However, the optimal temp for legionella growth is around 25 to 35 deg and I never let the tank get down to that temp.

Posted Saturday 25 Jul 2009 @ 7:02:57 am from IP #
ec175
Member

Solgen & Sunshine,

Thanks for the tips. I am having a look into some 40 tube options still with a view to using the heat pump / evac tube combination. I am confident that there is a good solution in there somewhere for our requirement. Have had some previous experience with Solahart flat panel units on a house we used to own in SW Sydney and temperatures that we used to get in winter were similar to your description above without boosting however the kids were much smaller then so I guess the demand was not so high (3 panel 315L system).

Posted Saturday 25 Jul 2009 @ 1:50:23 pm from IP #
nothappyjan
Member

Yesterday we parted with our reliable DUX Forte 315 electric HWS, it had been perfect but due to the $4200 grant on offer to replace with greater energy efficiency we took the bait. We now have installed a Saxon Heat Pump 400L. It looks the goods BUT: When you set the shower temperature as required and jump in, through the course of a shower it gets cooler and cooler needing 4

Posted Tuesday 18 Aug 2009 @ 7:37:27 pm from IP #
just2say
Member

Wow my story is so similar to nothappyjan .Installed a Saxon 2 weeks ago, not happy, not with unit, not with pressure,not with it going cold 3 minutes into having a shower, not with the consistent dripping and not with the after sales service either.Still waiting for someone to call me back from a week ago.I rang saxon and they told me to go on off peak 1 and told me to get our electrician back and turn up the temperature (another call out fee)and they would ring me back re the pressure. Also know of another person having similar problems. Didnt know about the spa thing and that just topsit right offas we have a spa. How does this unit get the recs and government backing? I wouldnt recommend Saxon heat pumps at all. STAY AWAY FROM SAXON

Posted Thursday 20 Aug 2009 @ 10:08:30 am from IP #
nothappyjan
Member

I have now explored many options to rectify the problem. It seems the most practical way is to install an instantaneous hws inbetween the heat pump and house. Fortunately we have natural gas. This is crazy to have two water heaters running but will at least guarantee hot water. I have no doubt that te Saxon will use little energy as it doesn't produce much hot water and the gas unit will at least have the bite taken out of the cold water inlet ensuring that its load is assisted. Hopefully I am still reducing my carbon footprint and hot water costs in the end compared to my old electric storage hws.
I would be very interested to know other people in the same situation and can be contacted at: vandarry@hotmal.com
Cheers

Posted Thursday 20 Aug 2009 @ 8:25:03 pm from IP #
ghostgum
Member

This raises interesting issues with RECs. Heat pump hot water systems create RECs because they reduce the amount of electricity used to heat water, but generally don't use renewable energy. Adding a solar hot water systems as a pre-heater also creates RECs, but when used as a pre-heater for a heat pump HWS will result in the total reduction in energy being subtantially less than the sum of the RECs. The gas industry is arguing that heat pump HWS should not get RECs.

I've got a split solar system, with an instant HWS as booster. Be aware that adding an instant HWS does add a lag to hot water delivery. Our kitchen requires 3 litres before the water is hot. About 1 litre in the pipes, and the remainder due to the gas instant HWS. Effectively this means we waste water, but save gas. The pipes are PE-X and were uninsulated, but equivalent to the 3mm green lagging on copper pipes. Adding 10mm foam insulation to the pipes doubled the heat retention, but only for the first 1 litre of the 3.

Posted Thursday 20 Aug 2009 @ 11:49:26 pm from IP #
just2say
Member

U need to have a restrictor before the heat pump of 9 - 11 ltrs u can also get the temperature changed to 64 low and 70 high. You need an electrician to do this but get the people from Saxon to send their people. You need to have a shower head that restricts the water flow as well. U will never have high pressure in your hot tap like u do in the cold but it should always be hot.(so they say). I have received a number of calls since me email to the Saxon company last night. I need a new relief value which wont be here until monday and I have to put up with the amount of water i will lose out of the overflow until it is fixed. Still not entirely happy, but have progressed in getting things fixed. Still would NEVER recommend the Saxon heat pump. if there is more to tell i will keep you posted

Posted Friday 21 Aug 2009 @ 5:13:22 am from IP #
nothappyjan
Member

I am very intrested my email is vandarry@hotmail.com not hotmal as previously written.

Posted Friday 21 Aug 2009 @ 5:22:10 am from IP #
Sunshine
Member

just2say and nothappyjan,

That's sure bad news about the Saxon Heat Pump not working as what it should. It's always really disappointing to part with good money, then find out what sales and service departments say are different.

I am very happy with the Hills evacuated tube solar HWS of 315 litres, been in 10 months and haven't had any problems, or need to use electric boost. We have more hot water available than with the gas HWS. With the old system we ran out of hot water when filling the spa, but the new solar HWS has greater volume and stores the water at a hotter temperature than the gas one.

They are one of the pricier systems available, as I was converting from natural gas, wan't eligible for any Govt SHWS rebates, except for RECS.

I agree, the heat pumps shouldn't be eligible for the solar government rebate as they still use electricity to run.

Posted Friday 21 Aug 2009 @ 5:59:46 am from IP #
just2say
Member

Sunshine

Im pleased you didnt make the same mistake i did by purchasing a Saxon, but I would like to tell them to take their unit and promplty you know what with it and than replace it with another system but on $$$ and principal I cant. Happy hot showering for you

Posted Friday 21 Aug 2009 @ 7:36:15 am from IP #
ec175
Member

just2say and nothappyjan,

Have just got back to the forums and am surprised and disappointed to see that the Saxon system has not met your expectations. Ours is in and working well however the installer who fitted ours had done plenty in the past and when we were talking about the install (pre-purchase) he did advise on some of the limitations of this system (heat exchanger type) compared to the other mains pressure types like Quantum, Stebel, Rheem etc. I also downloaded the install manual and had a look before purchase to see if I could live with the flow rate limitation compared to the mains pressure systems.

A couple of questions then:
- Did the installers of your systems fit a tempering valve on the outlet to bathroom (not mandatory but certainly recomended to keep the hot water flow rate through the cylinder at a minimum)?
- Did the installer carry out the flow rate adjustment to 9-12 litres a minute or did you have to do this after you experienced the cold showers?
- Did you have water saving shower heads fitted (max 9L min)?
- What tariff is the sytem on? Saxon specifically warns not to install on night supply only tariffs.
- Any significant improvement with thermostat at 70 deg C?

As already mentioned, ours seems to be going well thus far. It is not whisper quiet but we placed it in a position where the sound level (pretty similar to a small non-inverter split system outdoor unit in my opinion) is no issue for us or the neigbours. Have just completed all the rebate applications and sent off last week so I hope to have all but $70 of the purchase price back in the next month or two.

I have not had any issues with the tank overflowing beyond the first couple of days with the initial heat up of the storage tank (must go and have another look to as am ignoring the thing now).

Still planning to add a solar collector style type pre-heater to it in the future which should reduce our hot water related power consumption to a very low level.

Posted Saturday 5 Sep 2009 @ 12:42:03 pm from IP #
rockabye
Member

I have a Quantum Heatpump and intend to add solar pre-heating as well. Certainly no shortage of hot water with 3 people and 270l storage.

Posted Saturday 5 Sep 2009 @ 10:16:17 pm from IP #
nothappyjan
Member

I am curious here, are you telling me you can fill a bath with hot water? do you work for Saxon by chance?

Posted Sunday 6 Sep 2009 @ 7:58:40 am from IP #
ec175
Member

nothappyjan,

Unfortunately I can't do the bath test as it is sitting on the front porch (part way through a main bathroom reno at present) and I work for an aviation company not Saxon! I do have plenty of experience with air / water heat pumps from a past career in hydroponic horticulture and have a thorough respect for the energy efficiency compared to conventional electric HW heating systems however. Like you, I am having trouble reconciling the difference in our experiences, but I can certainly confirm that I am not trying to promote Saxon in any way shape or form (no cash for comment here).

I guess from your response that you have the already got the system set up for maximum performance (cont. or OP2 tariff, tempering valve, 9L min, 70 deg C etc)and the output is still not meeting your expectation?

I have just dragged out the brochures and guff that I collected at the time that I was looking into this unit and Saxon have been pretty clear about the measures that need to be taken with this system under "Settings for maximum performance" and it is pretty clear that the unit is not direct replacement for a conventional mains pressure large capacity unit like the one it replaced in my case (mine was a dual element so could run on peak when we ran out of offpeak H/W as well)or yours without some limitations. The info I am talking about is on the second page of the "Saxon Solarstar" pdf brochure and I guess that whoever sold it to you can't have checked that you knew what you were getting or that it suited your needs. Perhaps you can get them to take it back under some consumer law or another for misleading you that it was capable of the same perormance as the old Rheem unit without any other changes to your system?

Like you, my interest is reducing my carbon footprint and energy costs and the rebates at the moment make this system a near perfect low cost booster for the Solar thermal tank I plan to install in the coming months. I am sorry to hear that it has not worked out for you but perhaps a solar preheater or gas booster will restore your "normal" hot water availability without breaking the bank. It is certainly dissapointing to feel like you are doing the right thing (from an environmental point of view) only to find that you now have to live with compromised performance because the sales person did not properly inform you what you were buying.

Posted Sunday 6 Sep 2009 @ 3:13:34 pm from IP #
nothappyjan
Member

I must confess I am running off peak 2 which means I get a cheap night tariff as well as a not so cheap period through school hours; however I am not on continuous tariff. Even though Saxon does recommend a continuous tariff, their retailer that installs them in NSW “The Plumbing Doctor Newcastle” did not. In fact they did ask me to fill out a questionnaire after which, knowing my location, family size and requirements promptly (and incorrectly) recommended the Saxon 400L.
Nevertheless even though I have stepped outside the guidelines, I was trying to use the unit whilst “fully charged” and during a powered time and the unit continually failed. Not enough hot water for one shower without adjustment (full hot by end of shower) and well short of being able to satisfactorily fill a bath. This is not only incredibly irritating but totally unacceptable for anyone with children or elderly. I believe it would make no difference if I was on continuous tariff and neither does Saxon.
Ultimately due to these results Saxon have removed the unit and given a full refund for all costs associated with its delivery, installation and removal as they have stated “it will NEVER meet your requirements” In other words you will never get consistent reliable hot water.
I have now replaced the unit with a 26L continuous gas system which does reduce my carbon footprint and ongoing costs but does leave me substantially out of pocket as there is only a $300 rebate applicable. Oh well, you live and learn!
It is also annoying that our Government’s rebates are basically endorsing an inadequate product which ultimately is a big waste of taxpayer’s time and money. In my humble opinion there should be a review of the rebates scheme giving more credit for gas and less/zero for the inadequate products on the market.

Posted Sunday 6 Sep 2009 @ 8:12:32 pm from IP #
ec175
Member

Thanks for giving us the next instalment in this sorry tale! I would have thought that the OP2 would have been enough in any case so overall the result with the supplier taking the unit back and refunding the full amount is a good one even if it sounds like you have had to put up with a heap of aggravation along the way (I don't envy you the process for a minute).

Clearly you get through quite a bit of hot water and the 26L gas sytem certainly sounds like a good alternative given your circumstances. I guess that your old Rheem 315L system must have had a top element as well (on peak) if it was on OP1 or 2 to cope with the typical demands on your system or you used most of the water late in the evening before the OP1 came back on? Sorry for the "inquisition", it is just that I am still intrigued as to why mine works ok for us when it was so unsuccesful for you as we have both replaced a Rheem 315L electric system (ours dual element, OP1 & peak as already mentioned).

At least, there is now some decent feedback on this Saxon "heat exchange" type system (with its inherent characteristics) for anybody browsing on the topic as I was some months ago to help people make an informed choice and to get an alternative opinion to that provided by the sales people who are clearly not giving good advice in all cases.

Posted Sunday 6 Sep 2009 @ 11:36:47 pm from IP #
rockabye
Member

Data from my Quantum heatpump since install may be of some use in evaluating the performance of this type of HWS. I chose to install this type due to house construction issues preventing rooftop mounting of the solar flat plate type panels and because I wanted to get some real world data to feedback to prospective purchasers. The data represents 3 annual measurements at lat 23 deg S by 3 adults, one of whom was aged 16-19 for the test period.

Firstly the system replaced a 125litre electric HWS which used 10.5kWH/day for 63 days June/July 2006.

In 2007 the heatpump lost its gas in that very time slot so the data was corrupted. This may be because it was dropped off the pallet by the freight co on delivery. A loose connection was found and after warranty repair I kept daily records for a couple of months. About 4-5kWh/day in August September 2007.

In 2008 the consumption in June/July was 3.97kWh/day. For the same period in 2009 it was 5.3kWh/day.
This is an increase of about 33% over the previous year. It may indicate a loss of performance or increased hot water use. I have some evidence of the latter but the jury is still out at this time.

Overall I think it is definitely inferior to a solar thermal system from an energy consumption perspective. From a hot water temperature and usage perspective it is excellent. Noise levels are n negligible. However until someone buys one and records real world use you can only rely on sales talk. At a cost of about $2700 installed, after rebates, I did come close to choosing instantaneous gas but decided to conduct a real world experiment instead.

Apart from that I think the rebate schemes distort the market and inflate prices of both types of solar and electric heatpump systems. Perhaps rebates, or tax offsets, need to encourage lower household energy consumption rather than products. That way maybe quality, energy efficient appliances would reign supreme by default.

Posted Monday 7 Sep 2009 @ 6:20:38 am from IP #
rockabye
Member

Left off one piece of data.

Energy use from August 07 - August 09. 2480kWh over 730 days.

Average daily use was 3.4kWh.

Posted Monday 7 Sep 2009 @ 6:45:23 am from IP #
Sunshine
Member

I don't think the Federal Govt rebates should extend to heat pump electric. I went from gas storage to solar, and after 11 months haven't used any electric boost at all (100% solar only) but was ineligable for Federal Govt rebate except for RECS on installation.

But if consumers go from electric to heat pump electric, are eligible for $1600 rebate.

Looks like people who are on gas and want to go greener are given the rough end of the stick.

Stop press: New Policy Change

http://www.environment.gov.au/energyefficiency/solarhotwater/

This looks fairer, but still fails to support people going from gas to solar.

Posted Monday 7 Sep 2009 @ 6:56:25 am from IP #
rockabye
Member

They are certainly fiddling around the edges with current strategies.

I don't think my rebate was anywhere near $1600. As soon as they offered the higher rebate on heatpumps, prices jumped up to match it. Same thing is happening with home insulation.

Be interesting to see the prices when the rebates end.

Posted Monday 7 Sep 2009 @ 7:40:18 am from IP #
DW
Member

ec175,
Can you pass onthe details of the QLD distributor for the tube solar system you were looking at? I am in QLD and have quotes on Grenlands & Endless Solar Systems, which are both from southern states. I am keen to see if a system similar to them can be supplied in QLD a bit cheaper.

Posted Saturday 12 Sep 2009 @ 11:55:45 pm from IP #

RSS feed for this topic

12 Next »

Reply »

You must log in to post.