American Solartechnics Pellet Boiler

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mchasal

Burning Hunk
Jul 10, 2008
225
Hudson Valley, NY
Anyone seen the teasers that American Solartechnics has posted about their pellet boiler?
From their comments, it's gravity fed, 50kBTU, 85% efficient and less than $2k. It's designed to work with their storage. Can't tell much from what's been posted so far, but I'm interested to see what they have.



https://www.facebook.com/AmericanSolartechnics

They also have a hydronic air source heatpump that would integrate that they're working on:
 
We have been working on this for a while. Not much I wish to share other than some have asked about it. We are getting close to having it tested.
It is a different approach to pellet boilers. Is simple and does require a buffer tank.
We have been looking at this possibly as a part of an integrated system with an air source water heating heat pump. We have been evaluating a couple heat pump units this winter.

More to come as soon as we are comfortable sharing it. For now, it is kinda vaporware. Although we have been operating them for two years in buildings.
 
Thanks Tom, I won't hit you up with the dozens of questions I have since you can't share more yet, but it's very interesting to me. Hope all goes well in your testing and we see this sometime soon. Where's the beta tester sign up page? :)
 
I'll post it here first!
Hope to have some more to show soon.
 
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It's always been a peave of mine that all of this fancy heat pump technology is being wasted on forced air furnaces. Let's heat water with it!
 
It's always been a peave of mine that all of this fancy heat pump technology is being wasted on forced air furnaces. Let's heat water with it!
Agreed, I'm surprised that Mitsu or Fujitsu hasn't come out with a hydronic heat exchanger that would connect to their existing mini-split outdoor units. It would seem pretty simple to create a box with the controls and a plate exchanger to do that.
 
Agreed, I'm surprised that Mitsu or Fujitsu hasn't come out with a hydronic heat exchanger that would connect to their existing mini-split outdoor units. It would seem pretty simple to create a box with the controls and a plate exchanger to do that.

I have heard a couple of reasons. One is that the minisplits would have a hard time being efficient while replicating traditional boiler temperatures of 180 or whatever the old school baseboards need. The other is that they won't have cooling as an air conditioning system would.

In other countries they do have real, split, efficient, heat pump water heaters. Just not north America yet.
 
Mini splits are good at making lots of warm air not a smaller amount of hotter water. Storage capacity is dependent on the difference between the storage tank and the minimum temp that can be used for heating, thus heat pump technology isnt a good fit for most applications but I think Tom is currently trialing one, so we can await his report.
 
We tested two heat pumps this winter. One from China and one made in the US. Both have had their issues.
The Chinese unit works well in outdoor temps over 10F. Below that, it can kick out on high pressure and have to be reset. It then would run for a while.
It delivered about 120F water most of the winter when running. In March, it was excellent, since the temps were no longer arctic here in Maine.
Our electric bill went up about a dollar a day. We only operated it when here. It did not run on weekends, although it could have.

The other unit, made in the US was and is a nightmare. I will not name the manufacturer, but it is one that I know well.
They make a unit that is two components, one inside heat exchanger and the outdoor unit. The two units are connected with site brazed refrigerant lines.There is also a large control panel.
The manufacturer installed the unit. It did not work for almost a year. I suspect it got contamination in the system during the installation of the brazed
refrigerant lines. We finally had them remove the unit and rebuild it. It worked for several months at a time and is currently non functioning.
No one has serviced it yet after three weeks. Customer is not happy. I am not happy. I would've worked in it myself, but I am not a refrig. mechanic and the unit is still under warranty. This second unit did work all winter, when functional.

SO, lessons being learned. We will bring in another Chinese unit to test. My understanding is that Mitsubishi is going to introduce a new unit in January 2015 (!)
but it is not here yet. I want someone to help when there is a problem and have some pretty definite thoughts as to what we need, having handled a LOT
of DHW heat pumps, which have some similarities.

I have no doubt that a system with an air to water heat pump with wood or pellet back up and some storage is going to be valuable to us all.
 
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Good points about the temperatures that heatpumps can generate. So I guess they would only be useful for radiant or other low temp applications. I've got convectors now, which I think can run at a lower temp than baseboard, but not that low.

Thanks for the info on the ones you've been looking at Tom.
 
I am taking a hydronics course for the next 6 weeks and John Siegenthaler had mentioned a split unit that put outs out warm water. He didn't talk about it much but mentioned that it was the next bi g thing. I checked the link out and it looked like something I would wait awhile until they have larger distribution. What really is needed is a rebate program like the Bangor Hydro one so that there are a large number of units deployed so the factory takes interest in making sure they are installed correctly by competent distributors. I expect its worth waiting for mitsubishi but unless they do something radical I expect the storage issue is still major stumbling block for most folks. Of course in milder climates, there may be no need for storage
 
It was a few weeks ago so it may take some looking and I am already behind on a bunch of reading and homework.
 
The Daikin Altherma has been available state side for years. I think you get about 115 F water out of it. Single unit monoblock or split. Not a cheap unit though. I think its about $12-15k out of the box (i.e. plus installation).

I'm really curious if the US heat pump model is the new Spacepak heat pump. I welcome PM's about "heat pump boilers" from anyone who doesn't want to post publically.
 
It's always been a peave of mine that all of this fancy heat pump technology is being wasted on forced air furnaces. Let's heat water with it!

Heat pumps work most efficiently with distribution temps being about 90-100F. About a 20F lift ( temperature rise). A standard hydronic system will not put out enough heat at those temps. As you create higher temp water the efficiency drops considerably. That is the reason for what you see on the market.
 
I think it was the Daikin that John had linked but when I have a chance I will see if I can find it again.

Long ago I read an article about why a heat pump had a limited temperature rise. I think its related to the specific volume of the gas at the outdoor coil is so much different than the specific volume at the hot end that the compressor cant handle the specific volume difference. The supposed trick that makes cold source heat pumps work is that rather than use fixed speed compressors, they use variable speed which allows the compressor to deal with a wider range of specific volumes. I guess I need to figure out what flavor of refrigerant they are using and look for a Molier Diagram to see what the real story is.
 
Heat pumps work most efficiently with distribution temps being about 90-100F. About a 20F lift ( temperature rise). A standard hydronic system will not put out enough heat at those temps. As you create higher temp water the efficiency drops considerably. That is the reason for what you see on the market.

I know what you are saying here, but your choice of language is a little misleading. Here, let me translate slightly.

"A standard hydronic system will not put out enough heat at those temps." ---> A conventionally sized system will not put out enough heat at those temps.

"As you create higher temp water the efficiency drops considerably. " -------> As the water temperature drop through radiator (or heating coil, etc) increases the heat output drops considerably.

Designing a low temperature system and/or a system with a high temperature drop isn't such a big deal if you plan for it initially. But if you have a system designed for 150-180 F water then you are not going get much heat with the 115 F water. So hot water heat pumps are pretty lousy for retrofit solutions.
 
I know what you are saying here, but your choice of language is a little misleading. Here, let me translate slightly.

"A standard hydronic system will not put out enough heat at those temps." ---> A conventionally sized system will not put out enough heat at those temps.

"As you create higher temp water the efficiency drops considerably. " -------> As the water temperature drop through radiator (or heating coil, etc) increases the heat output drops considerably.

Designing a low temperature system and/or a system with a high temperature drop isn't such a big deal if you plan for it initially. But if you have a system designed for 150-180 F water then you are not going get much heat with the 115 F water. So hot water heat pumps are pretty lousy for retrofit solutions.

I was going to say the same thing and/or already did. The heat pump would have a hard time making 180 degree water so to defeat that obstacle, just utilize a radiation system that can use 115 degree water.

The mitsu air/air heat pumps can make full btu output at 5 degrees above zero. Take those btus and heat water with them instead of air.
 
The units we tested were a fair bit less expensive than the Daikin unit.
We did not test the Space Pak. It did not seem to be a good fit and there was some feedback that it was not going to work for standard hydronics.
I doubt that. I suspect it might work well, but was not inclined to spend that much money with no factory support.
 
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I believe the solution that Siegenthaler was probably referring to is a Japanese heat pump that goes under the generic name of "eco-cute" which is made by numerous Japanese companies.

These units use CO2 as a refrigerant and run at a pressure of around 600 psi. This makes them more costly due to beefed up components and construction and also has delayed their availability in N.A. due to the litigious environment present. I believe they are currently available only in commercially sized units. The big advantage they have over common market products is that they can deliver water up to 194F for water-water or water-air heat exchangers but require a delta T of 45F to achieve this. They also reportedly work efficiently in temps. down to -40F.

The following article contains more details.

http://www2.buildinggreen.com/blogs/heat-pump-using-carbon-dioxide-refrigerant
 
Tom. Regarding your new pellet boiler, congratulations on the great concept but why so small? 50,000 btu's is well below average rural heating needs imo. I would target 65,000 btu's as a more logical output target as most homeowners below that will choose a wood or pellet stove and happily pocket the difference in price. Look at your competition, rarely do you see boilers offered below 20 kws.
 
This is a boiler that currently delivers 50-100k. We are not looking at this as a complete replacement for every other pellet boiler out there.
It will be ideal for low energy homes and smaller homes where a $14k pellet device does not make sense.
We consider it as a back up for other systems such as the heat pumps mentioned earlier or solar thermal or for these lower heat load buildings.
We are going to make a larger output unit, but for now, we are starting small.
 
I believe the solution that Siegenthaler was probably referring to is a Japanese heat pump that goes under the generic name of "eco-cute" which is made by numerous Japanese companies.

These units use CO2 as a refrigerant and run at a pressure of around 600 psi. This makes them more costly due to beefed up components and construction and also has delayed their availability in N.A. due to the litigious environment present. I believe they are currently available only in commercially sized units. The big advantage they have over common market products is that they can deliver water up to 194F for water-water or water-air heat exchangers but require a delta T of 45F to achieve this. They also reportedly work efficiently in temps. down to -40F.

The following article contains more details.

http://www2.buildinggreen.com/blogs/heat-pump-using-carbon-dioxide-refrigerant

VERY interesting.

You could present a very big dT to one of those if you heat storage with it - run it for a few hours a day and you're good until the next day.

Maybe they will get to market about the time I want to be done with burning wood (said while knocking on said wood). Sign me up!
 
You could present a very big dT to one of those if you heat storage with it - run it for a few hours a day and you're good until the next day.

Would also let you put those few hours in non-peak electricity rate hours for those that have that available.
 
Would also let you put those few hours in non-peak electricity rate hours for those that have that available.

That's something else I'm waiting for here. It's sort of here, but to get it you need to buy & install (have installed) a real, 'approved', ETS heating unit. As far as I know. Which are kind of spendy I think. I have everything here already to do that with (electric boiler & water tanks), would just need to add a couple of controls & change a bit of piping - but that doesn't qualify. Unless they've changed things - been a little while since I asked. I will be asking again at some point.
 
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