Replies

1. GBA Editor
   Martin Holladay | May 19, 2016 09:54am | #1

   Peter,
   Here is a link to a previous Q&A thread on this topic: Solar thermal doesn't seem dead.

2. 
   pschonherr | May 19, 2016 12:55pm | #2

   Thanks for the link Martin. The post was from 2014. Is there any new information from any of the readers out there since?

3. 
   charlie_sullivan | May 19, 2016 05:34pm | #3

   I can't offer any new information, but if you told us about where you are thinking of applying it, that might lead to some possibly helpful discussion of whether it might make sense in that application. I realize, of course, that that wouldn't answer questions about reliability, etc., so I too hope there will be someone who sees this who can offer more newer information.

4. 
   4smartheating | May 24, 2016 01:43am | #4

   Perhaps I can share what I know. I am the managing director of the Solar Heat Pump Institute, CanSHPI is a non-profit focused on solar hybrids in conjunction with the IEA Task 44 project. I followed three years of installs and field testing going back to 2013. After SunPump was named a 2015 Solar Game Changer by CanSIA and won a couple NREL invites, plus Clean Tech contests, it was clear they have something big worth looking at. I have one at my home, and have spoken to other happy customers with hydronic radiant heat. We recently participated in a study on Heating Systems Cost & Performance, and SunPump was one of nine systems evaluated. http://www.sunpump.solar/radiant-heating-systems

   SunPump 3.0 is a solar-assisted direct exchange heat pump, a bit like Geo DX, except these solar panels are the evaporator and the hot water tank is the condensor/Thermal Battery. The installed cost came in a little more than the Ductless Split HP, but less than all three Furnace systems, and about 1/3 the expensive Geothermal. The SunPump had the highest net COP as installed, and the lowest annual operating expense of all 9 systems. The summary concluded SunPump 3.0 has the lowest Total Cost of Ownership in the rigorous white paper report. Ductless Mini-Split was second.

   A few notes I recall. Incentives were not considered for any system, however SunPump alone would receive the 30% ITA in 2017-2021. SunPump was measured indoors and outdoors, but the significant solar gains were not included because renewable energy is not part of other heat pumps tested. SunPump included a S/S 80 gallon hot water tank integrated under the heat pump in a fridge sized S/S square cabinet, that would be extra in the other systems. More than half the value of SunPump was ignored to fit test limitations.

   A PDF copy of the Heating Systems Cost and Performance report will be posted on our new web site page next week. You can request a copy by email: info (at) solarheatpump.org - or on request GBA can invite a guest post.

5. GBA Editor
   Martin Holladay | May 24, 2016 07:24am | #5

   Tania,
   GBA welcomes article submissions. If you would like to submit a proposed guest blog on solar-assisted direct exchange heat pumps, you can send it directly to me:
   martin [at] greenbuildingadvisor [dot] com.

   Thanks!

6. Expert Member
   Dana Dorsett | May 24, 2016 05:44pm | #6

   The Heating Systems Cost and Performance.report is hopefully a good read- the website is a bit fluffy, short on detail.

   I wonder how well it works in locations that can get 10' of snow or more over a winter?

   Any air conditioning or sensible cooling options?

7. 
   user-5946022 | May 24, 2016 10:01pm | #7

   Yes - please advise about air conditioning / cooling/ dehumidification component. The indicates you can get a fan coil unit for cooling - any option for a more traditional forced air system or even cassettes like ducted mini-split? Those fan coil form factors have the same aesthetic problem as the ductless mini-split. Also, how is the noise? We have all stayed in hotels with terribly loud fan coil units...- do the fan coils require mounting on an outside wall with a louver on the outside?

   Does the cost reference include the installed cost or just the equipment? Does it include the system of tubes in or below the floor?

   It looks like it includes an HRV. Any option for an ERV?

   If this includes the water heater, then if you have a problem with your water heater, your conditioned air also does not work and vice versa? Or is there a way around this?

   What is the hot water capacity and recovery?

   The page describing the design services show a structural steel shop drawing - does this system require additional installation beyond what is standard in residential construction?

8. 
   charlie_sullivan | May 27, 2016 11:39am | #8

   While we await the report, a few comments.

   One is that I prefer pre-packaged heat pumps where all the connections in the refrigerant system are made in the factory. That reduces the chances of leaks, and reduces the quantity that leaks if there is a leak. I know that properly made connections should never leak. I also know that not all HVAC contractors always do things right. (Shocking as it may seem, I have heard that there are some who size systems based on rules of thumb rather than a manual J calcuation!) Maybe we will have low GWP refrigerants in these systems someday, but for now it's a shame to see years of the climate benefits of an efficient system vanish in one big puff of refrigerant when something goes wrong. It would be interesting to know the details on refrigerant quantity to compare to mini-splits.

   Another comment is that if you put these collectors on your roof, you use up roof area where you might want PV instead. It looks like the size needed is pretty small, so perhaps that's not a major concern. But in some cases that tradeoff might need to be considered.

   That then raises the question of whether it makes sense to put PV on the front of these panels, in which case you could get the benefit of cooling the PV and boosting its efficiency as a side benefit. The idea of combining PV and thermal is an old one, and it usually falls flat once you realize that, in addition the general hazards of complexity, it has the basic incompatibility problem that the ideal temperature for DHW is higher than the ideal temperature for PV. But with a heat pump, you can run the panel at a lower temperature than the DHW, so it starts to make more sense. It's lots of fun to think about all the permutations possible combing PV/thermal panels with borehole energy storage, uninsulated underground tanks, insulated tanks underground or in basements, and heat pumps, and there are reports out there of people having success with many of them. But you can quickly get into ideas that are too complex and thus are expensive to install and maintain. Perhaps the sun pump does hit a sweet spot of getting some of the potential gains without excessive complexity, and perhaps the refrigerant quantity and leak potential aren't actually significantly worse than for mini-splits.

9. Expert Member
   MALCOLM TAYLOR | May 28, 2016 04:25pm | #9

   Energy Lite,
   Thanks for that. I doubt we will hear from Tania G again, although I sort of hope we do.

10. 
    user-1106426 | May 28, 2016 06:14pm | #10

    Smoke and Mirrors folks! Steer clear of this “disruptive game changer". The performance claims for the Sunpump seemed fishy, so I did a little digging on this company.

    Tania G, director of CanSHPI, is also the wife of Bruce Gray, owner of SunPump Solar. The Solar Heat Pump Institute is a non-profit ‘institute’ founded by Bruce to promote his own product. Sunpump and CanSHPI share the same address. That would make it easy for Tania G. to 'follow' SunPump installs and testing over the last few years.

    This type of misdirection is typical of the company’s self promotion. Pay attention to the artful language they use to describe the company’s awards and the system’s attributes.  SunPump didn’t win a Solar Game Changer award from CanSIA. They were only nominated. Same goes for the Vancouver Cleantech Championship.

    The Grays have now participated in a 'rigorous', yet unnamed, study in which their home’s sunpump comes out on top! I imagine they self-supplied both the installation costs and performance numbers used.  For all the talk, good luck getting some engineering data, 3rd party performance testing, or even a spec for the Sunpump. Real product shots are like unicorns, and most of the website pictures look ripped off from all over the web.

    Installation Costs: the system is marketed as cheap to install-in the $1000 range; yet it would require a refrigeration tech, a plumber, an electrician, and possibly a roofer for all the roof penetrations and mounting. Chinese… I mean Canadian-made equipment may be cheap, but you still have to pay the trades to get it installed. The installed cost from a dealer who wants to stay in business will be much more than Sunpump claims.

    Basic thermodynamics pokes many holes in the performance claims made.
    Cooling performance: try dissipating heat from black roof mounted panels in hot sunshine, without a fan. Not gonna happen efficiently, ever.  
    Cold climate heating: The website is peppered with photoshopped panels on snowy alpine roofs. Magically, they are free of snow and producing sufficient heat. The website FAQ sidesteps the very real concern of icing up in cold weather by discussing the -50˚C boiling point of refrigerant; which is irrelevant to the behaviour of liquid water in freezing temperatures. Backup heat isn't 'necessary', and a defrost cycle isn't included. If you don’t understand what’s wrong with all that, you’re the target market.

    This 'innovation' has already been done for years in dry, solar dominant climates like southern Spain. Attempts to pull it off in colder climates are being stymied by reality. It turns out sheets of aluminum can’t produce much heat in the dead of night when it’s actually needed. I’ll quote GCO from this thread to say what I’m too lazy to write myself:

    This seems interesting to heat up water during the warm, sunny season, but during inclement weather, I see two main problems.

    1) No sun, no heat.
    Those collector plates have dramatically less surface area than other heat pumps, and no forced air circulation around them, so can't get much heat from anything besides sunlight.
    So when it's rainy/snowy for days... just fire up the resistive heater?

    2) Snow and ice accumulation.
    This company shows its thermal collectors nicely photoshopped over a snow-covered roof, yet nothing I could find on its website describes how they deal with the snow and ice which will inevitably form on those plates.
    The defrost cycles of air-source heat pumps only have to deal with condensation, like inside a freezer. Attempting to also melt the snow falling on the collectors would require dramatically more energy, and will likely be futile until the weather improves anyway.

    Tellingly, the company also makes no comparison with air-source heat pump setups; I suspect it wouldn't be favorable.

    Have you ever looked at an evaporator or condenser coil? Did you see all those fins? Putting one every couple mm (8~12 of them every inch) increases the effective surface area 20 to 50x (yes, each has two sides too).
    Forcing air through instead of waiting for it to move on its own also again increases the volume which will come in contact, by another order of magnitude.
    This also limits the temperature difference imparted to the air traversing the system. Besides boosting efficiency, this reduces condensation and freezing on the evaporator.
    To recap, the Sunpump suffers from:
    – outside air throughput orders of magnitude lower than an ASHP,
    – lower condenser temperature makes it more prone to freezing,
    – no defrost capability, other than waiting for the next warm/sunny day.
    Good thing it has back-up resistive heat, for sure. Relying on it would sink the system's HSRP rating though; is this why Sunpump doesn't provide such numbers?
    "But when sunny, Sunpump has a COP of 7!". Great, but easily beaten by any solar thermal system. Passive ones (or just south-facing windows) in the same conditions even have a COP of infinity...

    Bruce claims the sunpump will completely replace a conventional heat source with no backup required. This qualifies it as cleantech that requires no capital cost. Say what? He also says their target market is California and Hawaii. At least that’s a step in the right direction. This technology has no place in a heating dominant climate, and the truthiness of this company is appalling.

11. 
    lkltrl | Mar 17, 2019 06:53pm | #11

    I installed a sun pump in July 2018. It ran great for 2 months and I really liked how it preformed. After 2 months it started cycling many times before it would come up to heat. It turned out to be the inverter board which I had to order from the factory in China(freight paid by me $275). Board was replaced by the factory.
    Installed the board and the machine worked properly for a month or so and I noticed some moisture in the overflow pan. Had to cut the machine apart and found at least four leaks in the tank. Tryed to have them welded which did not work.

    Now i have a sun pump that is useless, can not use because it is repairable.

    I terrible investment!!!!!!!!!!!!! Do not buy one

1. 
   GeorgeWiseman | Sep 15, 2020 06:25am | #14

   I'd appreciate some help.
   I installed a sun pump in 2017 and have been very happy with it. For me it worked as advertised until now.
   But now the board seems to be bad (error code 12) and the manufacturer seems to be MIA.

   I've become aware that the boards were manufactured in China. Any possibility that anyone here knows where to acquire one?

12. 
    lkltrl | Mar 17, 2019 07:01pm | #12

    Sun pump is un - repairable

13. 
    rockies63 | Mar 17, 2019 07:12pm | #13

    Apparently you can now buy the domain name listed in comment #4.

    I'd be interested in comments on the SunBandit system.

    https://www.sunbandit.us/