TIS UNI BOILERS & BUFFER TANKS

[Patti]

Hi! I apologize for this VERY lengthy post...but I need to pick the brains of you more experienced wood boiler operators out there I am considering buying a TIS UNI boiler from Belkomin. I have some questions about sizing, buffer tanks, and chimneys that I hope to get feedback on from members. If you're not familiar with this manufacturer, it is a modulating boiler (30-100%) and "Belkomin boilers use natural gasification with two air supplies for primary (pyrolysis) and secondary combustion. Since it is natural gasification the bottom part of the boiler is freed and a considerable gain of 20% firebox volume is made available."

The current system set-up I have is:
-mid-western Ontario (the snowbelt!)
-boiler in the shop with 100' pex running to the house
-600 gal stainless steel, insulated, non-pressurized storage tank (but it has never worked right with this boiler)
-Heat exchanger/ forced air in the house, in floor heating in stone floor in kitchen, temp of house usually 69-70degrees
-1857 log cabin with good insulation, but needs new windows, 2500 sq ft.
-shop is 4000 sq ft, heated only to 60F max
-hot tub in house (plumbed to take heat off the system but not hooked up yet)
- 45,000 L (11,000 gal) pool that I 'may' heat
-there will be a DHW tank hooked up
- 100,000btu propane back-up furnace in house
-will be installing a condensing propane boiler in the future.
Now...
I recently purchased 3 pressurized storage tanks that hold about 1200 gallons each.
I am not going to get a Heat Loss Calculation done because a) it's too hard to find someone who will do it. They aren't interested in trying to assess an 1857 log cabin because they say it's too complicated and time-consuming and b) the few would who do it wanted thousands of dollars to do so (and honestly, I would rather put that money towards the heating system itself). Based on the Benjamin boiler I have now (which is really only intended to be used as a back-up), and heating sources I've used over the last 12 years, I am estimating that I need approximately 100,000btus for the house, and then an additional amount for the shop, so perhaps up to 130,000btus. Here is a chart showing dimensions of some of the Belkomin boilers (for the models not included on the chart I put some basic specs below.)

UNI 65: KBTU: 30-70kW 7319 sq ft
UNI 75: KBTU: 35-80kW 8395 sq ft
UNI 85: KBTU: 40-90kW 9472 sq ft
SO....Here are my questions:
Based on the info I have provided (I know there are other factors, but best guess!), what size of boiler would people go with?
What about the storage tanks? How many would people use? (I have 3 I can possibly use, 1200 gallons each.)
Would it beneficial for me to buy a UNI95 and hook up as much water storage as possible?
I know very little about the storage/heat transfer- (all I know is that I am sick of stoking this Benjamin every 3 hours and going through 50 cord of wood!).
I want to have to stoke it as LITTLE as possible...but I don't know if it would make sense for me to heat up that much water all at once.
If I had the house heat at 69 degrees, the shop at 60 degrees, DHW (one person), and I heated all three storage tanks (3600 gallons) to 160-180 degrees, can anyone provide me with a rough estimate as to how long it might be between firings?
Or is this overkill? (BTW...the tanks are going to be insulated with sprayfoam and stored outside (likely in a shipping container).
Would it make just as much sense to go with a smaller unit (UNI65) and only have one tank?
The main reason why I started looking at gasifiers in the first place was because I can't take the smoke- inside OR outside. I realize this type of modulating boilers will emit more smoke than a true gasifier, but I can't (won't) spend that kind of money on something that I STILL have to cut, split, stack, and stoke with wood! So, I figured a modulating boiler with lots of water storage was the next best option, as I could run it full out until all the water was up to temp, and then it would shut right down and there wouldn't be smoke while it was idling and there wouldn't be creosote build-up either. I'd appreciate hearing people's thoughts and opinions about all of this Thanks for your input! Patti

 

[maple1]

Unless things have changed greatly since that other TSI thread, I would not buy one of those.

 

[Patti]

Unless things have changed greatly since that other TSI thread, I would not buy one of those.

Some of their customers that I have spoken to at length absolutely love these boilers- and one of them lives in the Yukon! He said they've never been warmer and couldn't believe the small amount of wood he went through. Another guy said he was really surprised by the amount of heat it produced and how little stoking it took. He is heating a huge house and garage (about 24 cast iron radiators I think he said.) The guy from the Yukon said that for the price, he really thought that the boiler would be flimsy and cheaply-made, but he decided to take a chance and was pleasantly surprised and very impressed with how solidly constructed it was. He said that the only drawback was that it took a little more cleaning than he had hoped (but it was still only about an hour a week- which is nothing compared to the time I spend dealing with 50 cords of wood!), and with more water storage I'm hoping to burn good hot fires, heat the water up, then let the fire go out, so maybe the cleaning won't be as much as others who don't have water storage and utilize the modulation. The only other drawback that a number of people have noted is the customer service....but on ebay, MBTEK had over 10,000 sales- and 100% feedback rating....which is pretty rare to see, so they must be doing something right! As I have said before, I'd love a Porsche...but the Vibe it is! As much as I'd love to have a true gasifier, I just can't afford these $10,000-$25,000 models. So, I know you say you wouldn't buy one of these... but do you have other suggestions that would be in the same price range? ($3000-$4000)? I can't even find used ones for that...and believe me, I've been looking. And even if I COULD find one, it's likely going to be at LEAST 10-15 years old...and I'm at the point that I really don't want to inherit other people's problems or have things starting to break down. Been there, done that with a pellet boiler that I spent/lost thousands on. But hey- if you know of any great used gasifiers for sale in that price range, please let me know! Thanks! Patti

 

[3fordasho]

Some of their customers that I have spoken to at length absolutely love these boilers- and one of them lives in the Yukon! He said they've never been warmer and couldn't believe the small amount of wood he went through. Another guy said he was really surprised by the amount of heat it produced and how little stoking it took. He is heating a huge house and garage (about 24 cast iron radiators I think he said.) The guy from the Yukon said that for the price, he really thought that the boiler would be flimsy and cheaply-made, but he decided to take a chance and was pleasantly surprised and very impressed with how solidly constructed it was. He said that the only drawback was that it took a little more cleaning than he had hoped (but it was still only about an hour a week- which is nothing compared to the time I spend dealing with 50 cords of wood!), and with more water storage I'm hoping to burn good hot fires, heat the water up, then let the fire go out, so maybe the cleaning won't be as much as others who don't have water storage and utilize the modulation. The only other drawback that a number of people have noted is the customer service....but on ebay, MBTEK had over 10,000 sales- and 100% feedback rating....which is pretty rare to see, so they must be doing something right! As I have said before, I'd love a Porsche...but the Vibe it is! As much as I'd love to have a true gasifier, I just can't afford these $10,000-$25,000 models. So, I know you say you wouldn't buy one of these... but do you have other suggestions that would be in the same price range? ($3000-$4000)? I can't even find used ones for that...and believe me, I've been looking. And even if I COULD find one, it's likely going to be at LEAST 10-15 years old...and I'm at the point that I really don't want to inherit other people's problems or have things starting to break down. Been there, done that with a pellet boiler that I spent/lost thousands on. But hey- if you know of any great used gasifiers for sale in that price range, please let me know! Thanks! Patti

Look at EKO boilers from Newhorizonstore.com - I think the smaller units are in that 3-4K range and plenty of users on this site.
I went with a little higher tech boiler from same supplier - an Lamba controlled Attack 45 kw unit. Very happy with this boiler.
There is also a supplier in Poland that will ship boilers to the US - EKO orlan and Atmos are good units they carry. (Kotly.com) - A few here have done this but I don't know what kind hassles you could run into so I chose to go through newhorizonstore. These are all downdraft gasifiers but none will be EPA 2020 compliant. The boilers from Newhorizonstore will be UL rated and include a step up transformer. The ones from Kotly.com will probably not be UL rated and will also require a step up transformer from 120vac to 240vac.

 

[mark cline]

interesting , I ll have to follow this

 

[maple1]

Some of their customers that I have spoken to at length absolutely love these boilers- and one of them lives in the Yukon! He said they've never been warmer and couldn't believe the small amount of wood he went through. Another guy said he was really surprised by the amount of heat it produced and how little stoking it took. He is heating a huge house and garage (about 24 cast iron radiators I think he said.) The guy from the Yukon said that for the price, he really thought that the boiler would be flimsy and cheaply-made, but he decided to take a chance and was pleasantly surprised and very impressed with how solidly constructed it was. He said that the only drawback was that it took a little more cleaning than he had hoped (but it was still only about an hour a week- which is nothing compared to the time I spend dealing with 50 cords of wood!), and with more water storage I'm hoping to burn good hot fires, heat the water up, then let the fire go out, so maybe the cleaning won't be as much as others who don't have water storage and utilize the modulation. The only other drawback that a number of people have noted is the customer service....but on ebay, MBTEK had over 10,000 sales- and 100% feedback rating....which is pretty rare to see, so they must be doing something right! As I have said before, I'd love a Porsche...but the Vibe it is! As much as I'd love to have a true gasifier, I just can't afford these $10,000-$25,000 models. So, I know you say you wouldn't buy one of these... but do you have other suggestions that would be in the same price range? ($3000-$4000)? I can't even find used ones for that...and believe me, I've been looking. And even if I COULD find one, it's likely going to be at LEAST 10-15 years old...and I'm at the point that I really don't want to inherit other people's problems or have things starting to break down. Been there, done that with a pellet boiler that I spent/lost thousands on. But hey- if you know of any great used gasifiers for sale in that price range, please let me know! Thanks! Patti

Maybe you should re-read that other thread.

These are not CSA approved. Which means therefore either you won't be able to insure your house, or you will find someone who will sell you some but it won't pay out if you need it. Like I said, unless some things have changed a lot since that other thread. I won't get into other stuff on why I would stay away from these, I think they were mentioned in that other thread.

Have you looked at the Smokeless Heat website? They have a banner ad on here. Gasifiers at a reasonable cost. And they are very good ones. And the easiest to clean on the market (since you mentioned cleaning).

 

[Patti]

Awesome! Thank you! I will check out that site. Yes, the CSA thing doesn’t thrill me for sure...even though it’s in my shop, I still wouldn’t want to lose that! But...I am at the point where I have given up on insurance companies anyways. I JUST settled a claim for a massive flood that destroyed my property 2.5 years ago...and even though I pay huge premiums for full replacement value, our wonderful governments have allowed insurance companies to put so many loopholes in the policies that I ended up getting less than 1/3rd of the damages...and I STILL have to clean up the mess that remains. Then...even though I have no control over the river or weather, they put my premiums up 15% while waiting for the claim to be settled, & as soon as it was, they informed me they wouldn’t renew my policy. (It was my one & only claim in 30 years of home ownership!). It’s mandatory to have insurance if you have a mortgage...but insurance companies have the RIGHT to deny you coverage???? What’s wrong with THIS picture??? GRRRRR....don’t get me started on insurance LOL. It’s a mighty sore spot with me! Thanks for the website tip! Can’t wait to go look at it now! Patti

 

[Patti]

Look at EKO boilers from Newhorizonstore.com - I think the smaller units are in that 3-4K range and plenty of users on this site.
I went with a little higher tech boiler from same supplier - an Lamba controlled Attack 45 kw unit. Very happy with this boiler.
There is also a supplier in Poland that will ship boilers to the US - EKO orlan and Atmos are good units they carry. (Kotly.com) - A few here have done this but I don't know what kind hassles you could run into so I chose to go through newhorizonstore. These are all downdraft gasifiers but none will be EPA 2020 compliant. The boilers from Newhorizonstore will be UL rated and include a step up transformer. The ones from Kotly.com will probably not be UL rated and will also require a step up transformer from 120vac to 240vac.

Thank you for this info. I will definitely go check out the EKO site. I’m in Canada, so I don’t have to worry about EPA compliancy (yet!) but I know it’s coming! British Columbia has wood burning emissions restrictions in place now, so I’m sure the rest of the country won’t be far behind. But that it’s a bad thing...I live in a valley and have a neighbour that has an OWB, and when it modulates down, it KILLS me (and my horses)because all the smoke from his boiler drifts downhill and settles like a haze all over my property. My lungs just can’t take it...(especially when I found out he was burning plastic-coated skids!! ) No wonder it was making me gag!! I think I have heard that Kotly name before. I will check into that.
A Lambda controller has always been on my wishlist but the boilers that had them were out of my price range, so I I’m eager to go check this out now. Thanks for the info! BTW...I love how you have the storage tanks. That was I was hoping to do, but I haven’t been able to find that size of tank anywhere around here (they are 1000 gallons right?). I’ve been looking online for a long time. I just found 3 tanks-1200 gallons each- but they are massive-surrounded by thick steel walls & weigh 2500-3000lbs. They are a LOT bigger than I ever wanted, but since I haven’t been able to find decommissioned propane tanks, (and for the price I got them for!) , I figured I better take them in case I couldn’t find the tanks like yours. Thanks again for your input! Patti

 

[3fordasho]

BTW...I love how you have the storage tanks. That was I was hoping to do, but I haven’t been able to find that size of tank anywhere around here (they are 1000 gallons right?). I’ve been looking online for a long time. I just found 3 tanks-1200 gallons each- but they are massive-surrounded by thick steel walls & weigh 2500-3000lbs. They are a LOT bigger than I ever wanted, but since I haven’t been able to find decommissioned propane tanks, (and for the price I got them for!) , I figured I better take them in case I couldn’t find the tanks like yours. Thanks again for your input! Patti

I have two 500 gallon propane tanks. I was also having problems finding tanks, very few on craigslist and overpriced when they did show up. I ended up calling local propane suppliers and asked if they had rusty/missing tag/ otherwise scrap tanks and the 2nd outfit I called had several. They even dropped them off for $200 each delivered. The only down side is they remove all the valves and then let them sit outside. I ended up cutting about a 20" square hole in the top center to access them properly for cleaning. I then had a local fab shop radius a piece to serve as a patch and welded them closed after cleaning. Also added a couple fitting ports in each. I would recommend a pro welder - did it myself and had to go through several rounds of pressurizing and leak checking to find leaks in my welds. As far as insurance, some places may require asme certified tanks, LP tanks would meet that until you weld them and then you need a certified welder. My install is in a un-insured out building, so some of these insurance concerns just don't apply to my situation. Also LP tanks are about 5/16" thick steel and probably designed for 300 psi - I am not concerned about mine holding 1 bar max (14.7psi) even after my modifications.

 

[Patti]

I have two 500 gallon propane tanks. I was also having problems finding tanks, very few on craigslist and overpriced when they did show up. I ended up calling local propane suppliers and asked if they had rusty/missing tag/ otherwise scrap tanks and the 2nd outfit I called had several. They even dropped them off for $200 each delivered. The only down side is they remove all the valves and then let them sit outside. I ended up cutting about a 20" square hole in the top center to access them properly for cleaning. I then had a local fab shop radius a piece to serve as a patch and welded them closed after cleaning. Also added a couple fitting ports in each. I would recommend a pro welder - did it myself and had to go through several rounds of pressurizing and leak checking to find leaks in my welds. As far as insurance, some places may require asme certified tanks, LP tanks would meet that until you weld them and then you need a certified welder. My install is in a un-insured out building, so some of these insurance concerns just don't apply to my situation. Also LP tanks are about 5/16" thick steel and probably designed for 300 psi - I am not concerned about mine holding 1 bar max (14.7psi) even after my modifications.View attachment 252230View attachment 252231View attachment 252232

Oh THANK YOU for these pics!! My plumber/HVAC friend who is here right now (who will be installing my system) is LOVING this!! LOL I can’t believe how SMALL your boiler is!! 45kW huh? How many square feet do you heat? (It’s in your shop and heats your house as well, right)? Forced air or radiant? DHW? So, in the winter when it’s -10C (. F) (we have similar winters I think), when you get your water storage tanks up to 180 how long does the heat last before you have to fire the boiler again? (I realize there are a number of variables & every house is different, but just a rough idea!) If your DHW is hooked in, how many people are using hot water? (It’s just me so I don’t go through much). I appreciate you letting me pick your brain - and the pics are really helpful!

 

[Patti]

Maybe you should re-read that other thread.

These are not CSA approved. Which means therefore either you won't be able to insure your house, or you will find someone who will sell you some but it won't pay out if you need it. Like I said, unless some things have changed a lot since that other thread. I won't get into other stuff on why I would stay away from these, I think they were mentioned in that other thread.

Have you looked at the Smokeless Heat website? They have a banner ad on here. Gasifiers at a reasonable cost. And they are very good ones. And the easiest to clean on the market (since you mentioned cleaning).

Ahhhhh! I knew that name ‘Smokeless Heat’ sounded familiar! I was seriously considering a Varmabaronen because you’re right- they do tend to be one that is more reasonably priced. But I priced it out, and by the time it was all said and done, the price inched up and it was in the $11,000- $12,000 range.

Oh THANK YOU for these pics!! My plumber/HVAC friend who is here right now (who will be installing my system) is LOVING this!! LOL I can’t believe how SMALL your boiler is!! 45kW huh? How many square feet do you heat? (It’s in your shop and heats your house as well, right)? Forced air or radiant? DHW? So, in the winter when it’s -10C (. F) (we have similar winters I think), when you get your water storage tanks up to 180 how long does the heat last before you have to fire the boiler again? (I realize there are a number of variables & every house is different, but just a rough idea!) If your DHW is hooked in, how many people are using hot water? (It’s just me so I don’t go through much). I appreciate you letting me pick your brain - and the pics are really helpful!

Is your Attack a DPX model or a SLX?

 

[3fordasho]

Oh THANK YOU for these pics!! My plumber/HVAC friend who is here right now (who will be installing my system) is LOVING this!! LOL I can’t believe how SMALL your boiler is!! 45kW huh? How many square feet do you heat? (It’s in your shop and heats your house as well, right)? Forced air or radiant? DHW? So, in the winter when it’s -10C (. F) (we have similar winters I think), when you get your water storage tanks up to 180 how long does the heat last before you have to fire the boiler again? (I realize there are a number of variables & every house is different, but just a rough idea!) If your DHW is hooked in, how many people are using hot water? (It’s just me so I don’t go through much). I appreciate you letting me pick your brain - and the pics are really helpful!

The boiler model is a DPXL45, about a 6.9 cuft firebox. The system has only been online for about 2 weeks so some of your questions I just can't answer yet. I have 1" pexalpex lines that run about 160ft to a 3400 sqft house. I have a 15 x25 water to air heat exchanger sharing the filter housing and a 24x24 water to air heat exchanger above the AC coil in the original forced air propane furnace. The two heat exchangers are plumbed in parallel with each other with valves so I can isolate or reduce flow to the smaller HX. I installed both in hopes of utilizing lower temps to extend storage. Lost heat from plumbing and storage seems to be doing a good job of keeping the building the boiler is in at about 58F so far although it's not real cold yet. The boiler room/shop is 24x48'. So far one burn per day easily gets storage back to full temp with only a partial load (firebox is deep and my wood cut too short). I am not heating DHW with the boiler and don't intend to as my heat pump water heater does a good job for us. I also run a wood stove in the fireplace room just because I like to watch a fire, but this is only in the evening. With only two weeks on the system and not running in really cold weather I can't report on that performance yet.

 

[Patti]

The boiler model is a DPXL45, about a 6.9 cuft firebox. The system has only been online for about 2 weeks so some of your questions I just can't answer yet. I have 1" pexalpex lines that run about 160ft to a 3400 sqft house. I have a 15 x25 water to air heat exchanger sharing the filter housing and a 24x24 water to air heat exchanger above the AC coil in the original forced air propane furnace. The two heat exchangers are plumbed in parallel with each other with valves so I can isolate or reduce flow to the smaller HX. I installed both in hopes of utilizing lower temps to extend storage. Lost heat from plumbing and storage seems to be doing a good job of keeping the building the boiler is in at about 58F so far although it's not real cold yet. The boiler room/shop is 24x48'. So far one burn per day easily gets storage back to full temp with only a partial load (firebox is deep and my wood cut too short). I am not heating DHW with the boiler and don't intend to as my heat pump water heater does a good job for us. I also run a wood stove in the fireplace room just because I like to watch a fire, but this is only in the evening. With only two weeks on the system and not running in really cold weather I can't report on that performance yet.

View attachment 252235

Omg...I’m laughing...this is EXACTLY what my plumber/HVAC friend is doing right now! He just took the fan out of my air handler and attached it to a new 2-stage propane furnace that I just bought. I bought it not really knowing how it would be hooked into the system, but I needed SOMETHING for heat since I didn’t get a new wood boiler yet, and I can’t handle stoking the Benjamin every two hours (and going through 50 cord of wood)! So I thought I would just run the furnace until the new wood boiler was in....but I didn’t realize what needed to be done to hook it into the system! I went downstairs to find my air handler dismantled, reassembled, attached to the furnace, mounted on a steel frame up at the ceiling (I live on floodplain) and all new ductwork planned with additional return air and heat vents added. Oh my......I had NO idea it was going to be THAT complicated LOL
My pex lines are about 110’ between my shop and the house. The house is 2500sq ft (plus 40 x 50 shop) so we’re heating a comparable amount of space. We’re on the same page! Lots of similarities!
So, you just got the Attack boiler? I’ll be interested in hearing updates about how the system is working for you as our surroundings turn into Arctic tundra! (Every year I ask myself why people continue to live in this climate lol. It really IS crazy. ) I’m sure my plumber friend and I will be asking you for more advice sometime soon (if that’s okay!) I just want him to get that duct work done now so I can turn some heat on!! I think it hit an amazing 14C (57F) here today...but that is going to change verrrry soon!

 

[3fordasho]

My pex lines are about 110’ between my shop and the house. The house is 2500sq ft (plus 40 x 50 shop) so we’re heating a comparable amount of space. We’re on the same page! Lots of similarities!
So, you just got the Attack boiler? I’ll be interested in hearing updates about how the system is working for you as our surroundings turn into Arctic tundra! (Every year I ask myself why people continue to live in this climate lol. It really IS crazy. ) I’m sure my plumber friend and I will be asking you for more advice sometime soon (if that’s okay!) I just want him to get that duct work done now so I can turn some heat on!! I think it hit an amazing 14C (57F) here today...but that is going to change verrrry soon!
[/QUOTE
I purchased the boiler in April. Had the propane tanks delivered mid August. Rented a mini-ex on labor day to dig the trench for the lines to the house. It has consumed my spare time since late August. I'm no expert on these systems and what I've picked was mostly from this forum and some free online training. I'm sure there is some optimizing that needs to be accomplished with this system, I still need to check my delivered water temps to the water to air hx to see if my flat plate heat exchanger is big enough and check the performance of the underground lines. One thing that's been an eye opener is the amount of heat lost to the boiler room - of course not lost because I want that area heated but further justification that an inside boiler was the way to go.

 

[3fordasho]

This would be the online training I mentioned:

Hydronics for High Efficiency Biomass Boilers

This course examines best practices for combining modern, high efficiency wood-fired boilers with hydronic distribution systems.

www.heatspring.com

 

[maple1]

Ahhhhh! I knew that name ‘Smokeless Heat’ sounded familiar! I was seriously considering a Varmabaronen because you’re right- they do tend to be one that is more reasonably priced. But I priced it out, and by the time it was all said and done, the price inched up and it was in the $11,000- $12,000 range.

Is your Attack a DPX model or a SLX?

Even if you ruled out one from Smokeless Heat, I would still be very reluctant and wary of the TIS. A true gasifier is worth a price premium, very much so in the years after install when you are left living with what you have.

 

[3fordasho]

Even if you ruled out one from Smokeless Heat, I would still be very reluctant and wary of the TIS. A true gasifier is worth a price premium, very much so in the years after install when you are left living with what you have.

Ditto, when you consider the amount of work installing one of these systems, and the costs of all the "other stuff" - valves, fittings, copper, boiler return protection, pumps, heat exchanger(s), storage tanks..... Don't cheap out by not going with a true gasifier.

 

[Patti]

Ditto, when you consider the amount of work installing one of these systems, and the costs of all the "other stuff" - valves, fittings, copper, boiler return protection, pumps, heat exchanger(s), storage tanks..... Don't cheap out by not going with a true gasifier.

Okay...I am listening to what you guys are saying. I am hoping Oscar 1111 will chime in and share his thoughts!! He was following the other TIS thread and last year he installed one of the TIS UNI boilers. He posted an update within the last couple weeks and he seems to be very pleased with the boiler. He said it would be interesting to install a true gasifier beside it solely to compare the differences because it seems that, like me, we aren’t ‘100% convinced’ that the extra cost is really worth it. I’m NOT SAYING it isn’t...I’m saying I’m NOT SURE. That’s why I love being on this forum - to hear people’s opinions and feedback - which I DO value, appreciate, and use in my decision-making! I just wish there were more people on this site that have these up & running! I’m going to ask the other customers I’ve spoken with to join. They would be better able to address any questions or concerns that are raised about the operation since they are currently using them.
My system is already in place for the most part and is ready for hot tub, DHW hook-up (I have the tank for it as well). I am VERY lucky- My plumber/HVAC friend gives me the parts for cost and does the work for next to nothing so that is a HUGE reduction in the overall costs is these systems.
With regards to the reservations I'm hearing, the data I am reading about these boilers on the manufacturer’s site ‘seems’ (to me!) to be similar to data about the true gasifiers.
For example:
1) They claim the flue gas temperatures are between 130-150C (266F-302F), so IF that IS TRUE, then does that not indicate that there IS secondary combustion of flue gases occurring before exiting? Otherwise the temperature of the flue gases would be considerably higher, right?
2) UNI boiler Efficiency ratings range from 82%-85%, and efficiency ratings of other manufacturer's (ie Atmos) range from 81%-92%, so these figures seem comparable.
So...other than asking a current owner for actual temperature measurements , how does one check to confirm this kind of data? I have written to the manufacturer and asked for information about what kind of certifications they have and how I can contact the certifying agencies (ie. Underwriter's Lab) but in the meantime, I'm going to research UL and European Standards.
3) Warranties vary, but most are 5-10 years, which again is comparable with some of the true gasifier models.
I'd like to be able to ask the manufacturer specific questions, so I am just curious as to what other kinds of issues there are concerns about- what would make you hesitant to buy one of these boilers (besides lack of CSA certification)? Thanks for your feedback everyone Patti

 

[maple1]

I think the other thread had the concerns voiced. But maybe being repetitive:

1) They claim the flue gas temperatures are between 130-150C (266F-302F), so IF that IS TRUE, then does that not indicate that there IS secondary combustion of flue gases occurring before exiting? Otherwise the temperature of the flue gases would be considerably higher, right?

No. Could also mean simply the fire inside isn't as hot.

2) UNI boiler Efficiency ratings range from 82%-85%, and efficiency ratings of other manufacturer's (ie Atmos) range from 81%-92%, so these figures seem comparable.

IMO those 82-85 figures are highly suspect. Ask for test results - I would bet they cannot be provided. The design I see in the cutaway just does not support that being possible. This is a relatively simple boiler design. That as far as I can tell offers not near the heat transfer efficiency available to a gasifier that incorporates tubes for good heat transfer.

Not sure what researching UL & Euro standards would gain. If it doesn't have a CSA stamp, it is not insurable in Canada.

I know what you went through with your Benjamin. I had one for 17 years. It was a pig of the highest order. I could never find any efficiency numbers anywhere for it, but now would estimate it maybe at 30%. Poor basic design, firebox totally surrounded by (and cooled by) water, with a direct exit to the chimney. After going gasser and looking at the boiler designs and the differences, and looking at that cutaway and seeing what it lacks from efficient boiler design, IMO it shares some aspects with the Benjamin design. (Shortage of heat transfer ability and everything surrounded by and cooled by water). That together with the flowery sales language common with other ordinary manufacturers that have come & gone over the years, and it feels & sounds like lipstick.

Again, just my opinion.

 

[maple1]

Will add one more thing.

It very well may be, that one of these would meet your needs and you would be happy with it. Just don't go in thinking it is everything it touts itself to be, and be aware of mis-speak in claims made.

 

[Patti]

Will add one more thing.

It very well may be, that one of these would meet your needs and you would be happy with it. Just don't go in thinking it is everything it touts itself to be, and be aware of mis-speak in claims made.

Thanks Maple1! I REALLY appreciate your input. I wrote to ASTM ( the Canadian Office) today and asked them numerous questions about international regulating standards for wood boilers, ( including questions about ASME, EN, UL, ISO, CSA etc.,), and how to CONFIRM certification. I also asked how you can verify claims regarding product performance (ie. where do I find the agency that tested the product and the ensuing data), so when I get some feedback from them I'll post it on here! I know what you mean about 'lipservice'!! But....I think EVERY manufacturer dresses up everything they can in order to sell their products! BS baffles brains, right hahaha LOL I was reading through some Triangle Tube condensing propane boiler brochures last night that my plumber brought back from a Trade Show...and ugh....SAME thing....enough with all the 'flowery' stuff....I don't care that it is 'aesthetically pleasing' LOL- just give me something that WORKS, is RELIABLE and won't cost me an arm and a leg!! I was reading some reviews of condensing propane boilers and one lady summed it up perfectly- they had their 'old furnace' cleaned once a year, and never had to have it serviced or repaired in over 30 years...and with the new one, it was a continual source of problems- and expense- since the day it was installed. I often think that 'new and improved' really ISN'T that at all! ("If it ain't broke....") (However....in the case of our Benjamins...well...that's a different story!! HAHAHA).

In the description of the UNI boilers it says this:
"Multi-stage air supply system in the primary and secondary combustion chamber, secondary fuel afterburning system.
An effective heat exchanger located in the upper part of the unit allows you to "send" the maximum heat received to the consumer’s house with minimal losses."
I've just sent a letter to the manufacturer and the Canadian distributor asking specific questions about the operation, including a number of questions related to the diagram, (which I feel needs to have more details and be better labelled- especially for someone like myself who knows very little about HVAC stuff. So....I'll see what they say and go from there. I can definitely see the points you are making- and I addressed them in the questions I was asking. One question I had is based on what I see in diagram which says the chamber at the top is "Flue Gas 3rd pass" ...so if that is 3rd pass, then I am 'assuming' the secondary combustion is taking place at bottom...but if there isn't forced air down-draft to increase the secondary combustion like true gasifiers, then how are the smoke and gases moved 'down' (I DO know that heat rises! HAHAHA). So, I now understand (I think!) that it IS possible that the flue gas temperatures could be the same as a true gasifier, because the temperature of the gases in this boiler would probably not be as high at the temperatures a true gasifier would be creating. Both are removing heat before exiting, but the true gasser will be able to extract MORE because the combustion temperature is higher. (Have I got that right?). When it comes to the efficiency ratings....I guess it will boil down to whether they had 3rd party testing done, or if they are basing their claims on in-house testing. We'll see! In the meantime...NOW you've got me re-thinking all of this (again! lol). I've been looking around some more and have found some decently priced EKO boilers...so....I won't be making any decisions until I get some feedback from the company. Thanks again for your input! Patti

 

[maple1]

True gassers extract more heat simply because they have better heat exchanging. Using tubes. Which this boiler does not have. Well, yes, they also make more heat in the burn to start with too. And IMO this boiler does not do any secondary combusting. Achieving secondary combustion with a water jacketed boiler (i.e. liquid cooled firebox) is practically or almost physically impossible.

 

[maple1]

Double posted.

 

[Patti]

True gassers extract more heat simply because they have better heat exchanging. Using tubes. Which this boiler does not have. Well, yes, they also make more heat in the burn to start with too. And IMO this boiler does not do any secondary combusting. Achieving secondary combustion with a water jacketed boiler (i.e. liquid cooled firebox) is practically or almost physically impossible.

Okay, thank you for explaining some of this stuff! I'm understanding much better now why you don't like these- and the similarities to our Benji's! You know...it's funny...I am totally aware of turbulators and the necessity of them- I had them in my pellet boiler- but for some reason I didn't even think about them not being in this unit until you pointed it out. This is SO helpful to have someone keeping me in line! lol I also need to go back and look at diagrams of other gasifiers because I thought that ALL boilers had water circulating around the firebox- I thought that was a part of how they worked...but not all boilers have water jackets? Such a learning curve....

 

[3fordasho]

Okay, thank you for explaining some of this stuff! I'm understanding much better now why you don't like these- and the similarities to our Benji's! You know...it's funny...I am totally aware of turbulators and the necessity of them- I had them in my pellet boiler- but for some reason I didn't even think about them not being in this unit until you pointed it out. This is SO helpful to have someone keeping me in line! lol I also need to go back and look at diagrams of other gasifiers because I thought that ALL boilers had water circulating around the firebox- I thought that was a part of how they worked...but not all boilers have water jackets? Such a learning curve....

The firebox on a downdraft gasifier is surrounded by water, however that is not where main fire is occurring. The main fire is occurring in the lower chamber as wood gas and air are sucked or pushed down through the ceramic nozzle into the lower chambers radiused ceramics, then once complete combustion has taken place reaching 1200F +, the heated exhaust is routed to the back of the lower chamber up through the heat exchanger tubes and out the back of the boiler.