Wow! I just had a 2
hr conversation with Bruce Gray. It was
at a presentation organized by Terrell Wong and Kathy Garneu, here in
Toronto. Bruce is the inventor and
founder of a disruptive technology called Sunpump, (see http://www.solar-hot-water.ca/) located in Vancouver. They have a new heating and cooling technology
that blows everything else right out of the water.
It is a major shift to a new way of the using the very
familiar vapour compression cycle. We're
all familiar with the mini split heat pump. They have been around quite some time, and over the years, their
efficiencies have improved. In the last
month or so Mitsubishi released (in Canada) their FH09 mini split heat pump
with a SEER rating of 30.5. That is news
in itself! But tonight, I learned about
something even better.
The Sunpump is a heat pump combined with a solar thermal panel -
but there is no glycol, and no water. The thermal panel hosts refrigerant. In addition, there is no outdoor fan. The thermal panel sits on the roof or on the wall, and exchanges heat
with the sun and the environment, without any moving parts on the outside of the
building. The panel is a solid plate of
aluminium with many small channels running through it. This configuration is classically difficult
to produce - but the company has overcome this challenge with the employment of
3D printing, so the panel is not two sheets stamped and brazed or somehow fused
together. It is a monolithic plate. It is anodized to be blackish, and has a
hydrophobic coating on it. What is
amazing about this whole concept is a number of things - and I feel dumb for
not having thought of it - but the elegance of the whole configuration is just
wonderful. Unlike regular evacuated tube
or flat plate solar panel systems, there is no stagnation, no drain-back, no
thick lines to the roof (the copper lines are 1/4" and 3/8" dia), no
freezing, no glycol, no pump, no fan, no nothing. The system is very economical to purchase because
there are so few moving parts. The only
moving part is the compressor rotor and perhaps a valve. But efficiencies are huge! Studies show that installed COPs of mini
splits are about 2.5 and groundsource heat pump systems, 3.5. This new technology has a COP of about 7 or
8, in the installed condition, and I think these numbers are not exaggerated. If you are a little familiar with heat pumps
and heat transfer, you'll see why. Even
evacuated tube solar panels have working fluids (water, glycol) that struggle
to take heat from an environment that is say -5 Celsius or colder outside. But when you have direct exchange with the
R410a refrigerant, which is operating at much lower temperatures, you can
extract heat from much colder ambient conditions. In addition, because there is no fan, there is no bulk movement of air over the heat exchanger (in this case the panel - in a regular mini split outdoor unit, it is a finned heat exchanger). This means there is no freezing of moisture on the heat exchanger, and a significant portion of the heat exchange is carried out via radiation. To top it off, the company also offers these
panels with PV cells grafted onto one side - so you can get electricity (just
like a standard PV panel) as well as heat. There are numerous hybrid panels on the market, including PV with Air,
PV with water/glycol - but this is PV with R410A refrigerant. This is a big step forward. And, finally, the system's output side seems
available in more than one configuration (which was always something I hated
about mini-splits - their lack of ability to have a hot water output at a good price). Sunpump offers their units with hot water
outputs as well as straight refrigerant outputs - so their systems can work
with hydronics as well as air-based HVAC systems. BTW, the system cools as well as heats.
Costing is only about $1/watt of total output - I believe
this includes the panels, accessories, and heat pump. This means the system is cheaper than many
many systems out there, and I think will even compete with the low price of natural
gas in North America. Apparently they
intend to compete on installation costs with electric baseboard heating!
The company is well developed already, has sold much product,
and has CSA approvals on their products also. And the panels produce some 7 to 8 times as much energy as regular solar
PV panels today produce (!!! - I know !). They also have partnered with a
financing company so builders can have these panels for ZERO dollars down - the
company recoups the money by having the consumer pay their energy bill savings
towards the loan.
So, this is the biggest, baddest news out there in the world
of energy systems. Absolutely must look
into this for every project, not even just low energy buildings. Remember the panels work at all hours of the day, (the thermal aspect of them), and on all sides of the house - they are
about twice as productive on the south side, but even on the north side, they
perform well compared to other heat pump systems.
I discussed groundsource with Bruce as well. He said their testing showed ground source loops to eventually degrade in their heat transfer capability due to freezing and shifting of the soils around the pipes - but the performance potential is ultimately limited by the working fluid. There have been what are called direct exchange systems in the past, in which refrigerant is passed directly into copper pipes in the ground - but the copper seemed to be unreliable and developed leaks, etc. (I 've heard also of the difficulties in these systems). One great advantage of the groundsource system is that they tend to store the summer's heat in the ground, and then, later, store the winter's cold in the ground as well, reducing both heating loads and summer air conditioning loads. This system does not have an inherent storage aspect like the groundsource, but the simplicity and greatly increased efficiencies seem to me to make things much more worthwhile with these thermal panels - ultimately groundsource has some environmental issues and is really quite expensive, as well, and involves a fair bit of plumbing and pumping. The Sunpump system does away with that. Storage can be added to the system of course, with the use of a water/ice tank.
So - it is not often I am impressed with a new product - but this is one of those times. The concept is absolutely fantastic, and the product appears to have great potential.
Actually, I was badly conflicted in writing this article. They are currently in explosive growth mode, so production is very tight and it may be hard to get a unit right now - and of course, I want one, so I didn't really want to tell everyone about it - but hey - must do the right thing......and tell you all.
Have at it!
I discussed groundsource with Bruce as well. He said their testing showed ground source loops to eventually degrade in their heat transfer capability due to freezing and shifting of the soils around the pipes - but the performance potential is ultimately limited by the working fluid. There have been what are called direct exchange systems in the past, in which refrigerant is passed directly into copper pipes in the ground - but the copper seemed to be unreliable and developed leaks, etc. (I 've heard also of the difficulties in these systems). One great advantage of the groundsource system is that they tend to store the summer's heat in the ground, and then, later, store the winter's cold in the ground as well, reducing both heating loads and summer air conditioning loads. This system does not have an inherent storage aspect like the groundsource, but the simplicity and greatly increased efficiencies seem to me to make things much more worthwhile with these thermal panels - ultimately groundsource has some environmental issues and is really quite expensive, as well, and involves a fair bit of plumbing and pumping. The Sunpump system does away with that. Storage can be added to the system of course, with the use of a water/ice tank.
So - it is not often I am impressed with a new product - but this is one of those times. The concept is absolutely fantastic, and the product appears to have great potential.
Actually, I was badly conflicted in writing this article. They are currently in explosive growth mode, so production is very tight and it may be hard to get a unit right now - and of course, I want one, so I didn't really want to tell everyone about it - but hey - must do the right thing......and tell you all.
Have at it!
