My Windhager Biowin install

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bdud

Member
Sep 19, 2013
167
Franklin, MA
I thought I would post a few pictures of my Windhager Biowin pellet boiler install.
The final inspection happened last Friday, Marc did a test fire but the boiler has not been used in anger yet.

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Working on insulating the pipes, what a pain.
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To the left below is the Turbomax storage tank. To the right is the Caleffi solar water tank for hot water. Electric element for standby (never used), boiler heats the tank on separate zone but for summer use Nyle Geyser-RO heat pump. We have 5 adults living in our house and this heat pump supplies all our hot water needs. No-one has complained of a cold shower, we have a cool, less humid basement. I also plumbed the condensate drain to the pump below which feeds some little sprinklers installed in a vegetable plot at the back of the house.
I will be turning the heat pump off when I kick on the boiler.
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Custom built ~3.5 ton silo which fits nicely in the nook where my old oil tank used to reside.
Check out how I had to design the silo high enough so the fill and vent pipes would clear my basement door.
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2 suction probes installed in the base, one for the Windhager and the other for...
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A Cornvac. I use a 6.5hp shop vac to suck pellets out of the silo into a holding tank.
I place a pellet bucket under the holding tank and open the valve.
These pellets are for our Harman pellet insert stove upstairs.
Now I never hope to have to buy pellets in bags again..
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Bring on winter..
 

Paste

New Member
Aug 13, 2013
35
NH
Wow! Great setup. I just got a Biowin yesterday and hope to have it installed soon, too. I really like your storage bin setup.
 

Tennman

Minister of Fire
Mar 4, 2009
991
Southern Tenn
Wow..... I think I recall Heaterman saying storage was unnecessary with this system? Very impressive bdud. Don't just disappear like many satisfied users do. Let us know how you like it. Yeah I'll say it again backwards... wow
 

Dana B

Feeling the Heat
Mar 17, 2013
434
So. New Hampshire
That is impressive. Did you build the silo yourself?

My basement is all open and I have to insulate all of the piping too. I was going to do that this weekened but the boss said this weekend has been booked already. Apple & pumpkin picking with the rugrats.
 

bdud

Member
Sep 19, 2013
167
Franklin, MA
Wow..... I think I recall Heaterman saying storage was unnecessary with this system? Very impressive bdud. Don't just disappear like many satisfied users do. Let us know how you like it. Yeah I'll say it again backwards... wow
Thanks Tennman, been a lurker for a while..
I got a lot of information and ideas from this forum.
In MA we get a $15,000 max grant for a small pellet boiler install. A requirement of the grant is the bulk storage, my basement is small and I could not fit a regular square storage hopper, hence the custom bin. A major requirement for me was the automatic delivery, I felt in years to come, I do not want to continue lugging bags around and the grant was a fantastic incentive.
It took a lot of work and planning. Hopefully not much more complicated or maintenance required than an oil or gas setup.
I also put in some zwave water / temp sensors. These are linked up to water valve plumbed into my water supply.
If any of the battery / wireless sensors detect water, they sound a siren in the house, send me a message and email and shuts off the water supply in the house.
I was worried about ruining the basement, boiler, pellet store, etc, with having over 180 gallons of water storage down there.
Really works well, Fortezz.
I also wired one into the condensate pump which is connected to the heat pump and boiler supply tank, in case / when the pump fails.
 

Dana B

Feeling the Heat
Mar 17, 2013
434
So. New Hampshire
Thanks Tennman, been a lurker for a while..
I got a lot of information and ideas from this forum.
In MA we get a $15,000 max grant for a small pellet boiler install. A requirement of the grant is the bulk storage, my basement is small and I could not fit a regular square storage hopper, hence the custom bin. A major requirement for me was the automatic delivery, I felt in years to come, I do not want to continue lugging bags around and the grant was a fantastic incentive.
It took a lot of work and planning. Hopefully not much more complicated or maintenance required than an oil or gas setup.
I also put in some zwave water / temp sensors. These are linked up to water valve plumbed into my water supply.
If any of the battery / wireless sensors detect water, they sound a siren in the house, send me a message and email and shuts off the water supply in the house.
I was worried about ruining the basement, boiler, pellet store, etc, with having over 180 gallons of water storage down there.
Really works well, Fortezz.
I also wired one into the condensate pump which is connected to the heat pump and boiler supply tank, in case / when the pump fails.


Did you talk to Marc at all about the outdoor reset for the Biowin? He and I talked about it briefly. It's not been released yet but I'm definitely thinking about picking one up when it is. The other thing I was looking into was the IP thermostats.
 

bdud

Member
Sep 19, 2013
167
Franklin, MA
That is impressive. Did you build the silo yourself?

My basement is all open and I have to insulate all of the piping too. I was going to do that this weekened but the boss said this weekend has been booked already. Apple & pumpkin picking with the rugrats.

I had the silo built with a lot of help from Alan at Vermont Renewable Fuels, contact him if you want prices, Marc also has all the information.
I got the "deflection plate" and suction probes from Marc.

I had previously insulated all my piping with the rubber pipe insulation but the adhesive fails eventually and looks horrible.. :)
I am trying the fiber glass paper covered stuff, not that nice to work with, doing it in phases..

I dont have many before / during pictures.
 

bdud

Member
Sep 19, 2013
167
Franklin, MA
Did you talk to Marc at all about the outdoor reset for the Biowin? He and I talked about it briefly. It's not been released yet but I'm definitely thinking about picking one up when it is. The other thing I was looking into was the IP thermostats.
Yes we spoke about the outdoor cutoff when a delivery was planned / being made.
I thought about wiring it via the water level switch or maybe there is some output that they use in other countries.
With the z-wave water valve, sensors, controller, I have I could wire up a remote / iphone switch so I could put the unit in standby an hour or so before delivery.
I also would still have the outside switch which sounds like it is necessary.
I have some very nice thermostats that show outside temp, which control my 2-stage ac, heat pump heating, super dehumid, humidifier and also the pellet boiler.
I am not sure I want to change my thermostats yet.
 

Dana B

Feeling the Heat
Mar 17, 2013
434
So. New Hampshire
Yes we spoke about the outdoor cutoff when a delivery was planned / being made.
I thought about wiring it via the water level switch or maybe there is some output that they use in other countries.
With the z-wave water valve, sensors, controller, I have I could wire up a remote / iphone switch so I could put the unit in standby an hour or so before delivery.
I also would still have the outside switch which sounds like it is necessary.
I have some very nice thermostats that show outside temp, which control my 2-stage ac, heat pump heating, super dehumid, humidifier and also the pellet boiler.
I am not sure I want to change my thermostats yet.


Who makes the thermostats that you have?
 

bdud

Member
Sep 19, 2013
167
Franklin, MA
Who makes the thermostats that you have?
I think it is this one or very similar, Carrier make quite a few different models with slight differences.
http://www.ebay.com/itm/Carrier-EDG...569?pt=LH_DefaultDomain_0&hash=item2a318d4251
It has some nice features. Large display and you can see the outside temp if you wire in the sensor, great for deciding if you really want to get out of bed in the winter.
You change change the light level of the display.
You can also have a remote remote room sensor which can be the primary or it use an average temp with the internal display sensor.
If you want to increase or decrease a temp, you can also change for how many hours, 2 hours is default.
It does require 3 wires as a minimum to the controller, ie you need to wire to both sides of the 24v transformer.
It can be wired with 2 wires to the display and the controller itself can be at the boiler.
 

Dana B

Feeling the Heat
Mar 17, 2013
434
So. New Hampshire
Have you started using your's yet bdud? I'm having 2 tons of pellets delivered tomorrow but it will be another week at the earliest before we start using the boiler.
 

bdud

Member
Sep 19, 2013
167
Franklin, MA
It is not that cold yet down here. 49F outside and 75F in the house which stays at a more constant temp since we had the rafters insulated with spray foam.
Not sure when we will start using the boiler.
I loaded up the hopper with the ~1.2 tons of super premium pellets I had bought last season.
I gave up insulating my pipes with white paper/ fiber glass pipe insulation, messy very time consuming, super expensive also.
Using the rubber foam with adhesive for the 90's etc.
When I was storing pellets in the basement, I mounted some heavy duty wheels on the bottom of a strengthened pallet.
It made it a lot easier if you had to get behind your stack.
 

heaterman

Minister of Fire
Oct 16, 2007
3,374
Falmouth, Michigan
I think I detected a little confusion regarding the term "storage" in the posts above. One person referencing my comment about not needing storage (thermal) and the other person thinking storage as in fuel.

I'll explain my comment about storage in the thermal sense of the word. A pellet boiler like a Windhager that is able to modulate burner output and start up/shut down as easily as this particular unit can really diminishes the need for thermal heat storage. A person can if desired simply connect the boiler to his existing heating system and let it start up/shut down just like a gas or oil boiler. There are a couple controls that need to be in place to do this in order to prevent overheating and excessive number of cycles per hour. These will depend on the system the boiler is connected to but the only downside is the increase in on/off cycles per ton of fuel and a little less system efficiency.

That being said, I have found that these units work best with the type of system they were originally designed to service, which is of course a European style heating system.
The primary difference between a Euro type system and what we see here in North America is that the Euro's set up nearly all their heating systems to run in a variable and proportional mode. A prime example would be a panel rad system with TRV's controlling flow to the rads.

That type of system is always in the "on" mode and the boiler is able to vary its output in proportion to demand from the radiators. Running the heat in the "on" mode all the time and letting the boiler ramp up and down according to load is like cruise control on your car. You are going to see an increase in economy plus less wear and tear on components due to fewer burner cycles.

In my own house/test lab, I have a combination of radiators with TRV's, a constant circ radiant floor with weather responsive variable temperature and some standard old baseboard controlled by zone valves. So something is nearly always calling for a little heat. The only thermostat in the house is upstairs on the baseboard zone. The boiler is always in the on mode.
The Windhager responded beautifully to this system and spent most of it's time between 35-65% firing rate. Mild weather in the spring saw it drop to 30% and the water temperature creep up to maximum setting, then it would shut down and wait for the water to cool off. I think it averaged about 5 on/off cycles per day for the entire 1100 hours of operation rather than the 4-6 cycles per hour that are common with North American style heating systems that operate in an on/off mode.

In a case where you might connect one of these to a single "zone" or load that does operate in an on/off mode, one of the methods to minimize cycling would be to install a buffer tank. The size would not need to be very large, maybe 40-50 gallons. Just something for the boiler to work into rather than only 10-15 gallons of system capacity. Even that small amount of thermal storage would reduce on/off cycles by a significant amount. Around here there is a lot of forced air systems that typically get a hot water coil in the plenum of the furnace which is about the worst type of system for creating high cycle counts. On a couple of those we've added a radiator or two if the customer has cold spots in the house to provide the effect of a little constant load. That has worked out really well both for reducing on/off cycles as well as solving a problem for the customers house.

So to sum it up. No. You do not absolutely have to have storage on one of these boilers. It is advantageous however from an operation and efficiency standpoint if you can incorporate some level of a base load for the boiler to work with.
 
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Dana B

Feeling the Heat
Mar 17, 2013
434
So. New Hampshire
As always we appreciate the information heaterman. I have a question regarding the Biowin actually cycling on and off less than an American style boiler. Do you believe that the less frequent cycling will actually lead to the parts in the Biowin lasting longer and a longer overall life for the boiler? Having experience with the unit I'm just curious what your take as to what the expected maintenance intervals and boiler life will be.

Thanks
 

__dan

Feeling the Heat
Oct 5, 2011
331
An outdoor reset control would continuously vary the hot water supply, HWS, temp according to outdoor air temp, OAT, to more closely match boiler output to demand . If the boiler is not a condensing rated boiler, HWS would have to be maintained above the condensing temp, usually ~ 140 F, but you would still risk condensing in the flue at low temp operation. It does not appear from the pictures that outdoor reset was implemented, so the boiler would have a fixed, higher, HWS setpoint and turndown firing rate above setpoint. The hotter HWS satisfies demand faster and the boiler goes off. Load is not matched proportionally to demand. (assuming fixed convection baseboard loads).

Shorter boiler lifetime would be primarily caused by condensing operation if the boiler is not rated for it. The boiler should be designed for many burn on, burn off, cycles. Varying load on the boiler to match demand, with OAT reset or other, would greatly reduce the quantity of on / off cycles as the boiler stays on but turnsdown firing rate to match load - the load stays on longer at a lower HWS.

I'm writing this post because I was curious what the installing dealers were offering for hot water reset and how they were offering the implementation. A boiler rated for low return water temp and a rating for condensing operation are two vastly different things. If the boiler is not rated for condensing operation ie, HWS below 140 F, outdoor reset would have to be implemented externally with primary secondary piping and a variable speed injection pump or 3 way valve resetting the distribution loop temp based on OAT, while the primary boiler loop HWS stays above the condensing temp.

It would not surprise me if there is widespread misunderstanding of this in the industry. But OAT reset of the load HWS is one of the biggest ways to wring the available efficiency gains from the boiler. The load stays on longer at a lower HWS and the boiler dials in its firing rate to stay on at a steady lower demand. That's the objective. It seems your boiler is ideally suited to this and my question is about the implementation.
 

Dana B

Feeling the Heat
Mar 17, 2013
434
So. New Hampshire
An outdoor reset control would continuously vary the hot water supply, HWS, temp according to outdoor air temp, OAT, to more closely match boiler output to demand . If the boiler is not a condensing rated boiler, HWS would have to be maintained above the condensing temp, usually ~ 140 F, but you would still risk condensing in the flue at low temp operation. It does not appear from the pictures that outdoor reset was implemented, so the boiler would have a fixed, higher, HWS setpoint and turndown firing rate above setpoint. The hotter HWS satisfies demand faster and the boiler goes off. Load is not matched proportionally to demand. (assuming fixed convection baseboard loads).

Shorter boiler lifetime would be primarily caused by condensing operation if the boiler is not rated for it. The boiler should be designed for many burn on, burn off, cycles. Varying load on the boiler to match demand, with OAT reset or other, would greatly reduce the quantity of on / off cycles as the boiler stays on but turnsdown firing rate to match load - the load stays on longer at a lower HWS.

I'm writing this post because I was curious what the installing dealers were offering for hot water reset and how they were offering the implementation. A boiler rated for low return water temp and a rating for condensing operation are two vastly different things. If the boiler is not rated for condensing operation ie, HWS below 140 F, outdoor reset would have to be implemented externally with primary secondary piping and a variable speed injection pump or 3 way valve resetting the distribution loop temp based on OAT, while the primary boiler loop HWS stays above the condensing temp.

It would not surprise me if there is widespread misunderstanding of this in the industry. But OAT reset of the load HWS is one of the biggest ways to wring the available efficiency gains from the boiler. The load stays on longer at a lower HWS and the boiler dials in its firing rate to stay on at a steady lower demand. That's the objective. It seems your boiler is ideally suited to this and my question is about the implementation.



Whoa. You guys are definitely talking above my pay grade. I'm actually an IT guy but I'm finding the advice that the heating/plumbing guys have to offer on here to be invaluable. I am not exactly sure how the outdoor reset for the Biowin is going to work. It has not even been released yet but I know that it is in the works. I plan on picking one up providing that it makes sense to do so for my system and is cost effective. If you're curious about the reset for the boiler or the boiler itself you may want to reach out to Marc Caluwe who is the distributor and who posts on this site.
 

__dan

Feeling the Heat
Oct 5, 2011
331
Forgot to say congratulations. Looks like a great move overall that should give you many years of service and pride in beating the oil companies at their game.

There are many more who should make the move you have. It would be nice to see the future fuel savings numbers, cost of oil vs cost of pellets over the heating season.

I have a Froling setup as described, primary secondary loops with OAT reset, VSD injection pump into the distribution loops. If the timing were different, I would consider offering the control installs in the market.

Enjoy your heat.
 

bdud

Member
Sep 19, 2013
167
Franklin, MA
Wow..... I think I recall Heaterman saying storage was unnecessary with this system? Very impressive bdud. Don't just disappear like many satisfied users do. Let us know how you like it. Yeah I'll say it again backwards... wow
Ah, thank you Heaterman for picking up my mistake about storage, wrong storage..
Part of the MA grant is thermal storage also, they allocate $2,000 for that, I think my tank is 100 - 110 gallons.
 

bdud

Member
Sep 19, 2013
167
Franklin, MA
Whoa. You guys are definitely talking above my pay grade. I'm actually an IT guy but I'm finding the advice that the heating/plumbing guys have to offer on here to be invaluable. I am not exactly sure how the outdoor reset for the Biowin is going to work. It has not even been released yet but I know that it is in the works. I plan on picking one up providing that it makes sense to do so for my system and is cost effective. If you're curious about the reset for the boiler or the boiler itself you may want to reach out to Marc Caluwe who is the distributor and who posts on this site.
I only spoke to Marc about a switch that would shut down or pause the boiler when a pellet delivery is expected to my bulk storage.
I do not know if there is an outside air temp connection on the Windhager boiler itself.
Windhager does make a room controller/thermostat that monitors and uses outside air temp, these are not sold in the US I believe. Not sure if this is the function an OAT reset provides.
Most of my room thermostats have an outside sensor for temp and humidity control, though each controller is connected to a master zone controller which controls the turning on or off of the boiler. I was interested to see how my setup runs in this way.
Marc also mentioned a different way of wiring the boiler and letting the boiler internal water sensor control when the boiler needs to turn on and heat the water for the storage tank. :)
Maybe the "thermostat control" would work better in the fall and spring with less heating demand and the "water temp control" working better in the colder, higher demand times.
Thoughts on this?
 

Dana B

Feeling the Heat
Mar 17, 2013
434
So. New Hampshire
Marc mentioned that Windhager is in the process of developing an outdoor reset module for the Biowin which will eventually be avialble in the American market. Prior to purchasing the Biowin I had (still have) a Taco outdoor reset on my oil boiler. I'm sure the heating/plumbing professionals can explain it much better than I can but my laymen's understanding of the outdoor reset is that it is a controller that senses the temperature outside and on days when it may be a little warmer outside it lowers the water temperature in the boiler thereby making your boiler run more efficiently.

Marc also said that Windhager is not going to be selling their thermostat/controller in this country at this time.

We had been speaking about the IP based thermostats earlier. Since then I came across these

https://www.ecobee.com/

They're pretty swanky. Also pricey though.
 

__dan

Feeling the Heat
Oct 5, 2011
331
Well I looked at the internet literature, the brochure, and what I could gather is the boiler is not condensing rated (as expected) and has a turndown ratio in the range of 3 to 1.

What this means is OAT reset of the HWS would not be an internal to the boiler electronic feature like it is with a gas condensing boiler. It would have to be implemented externally as a primary secondary piping with OAT reset of the secondary load loop piping. That is, it is not a feature you would wait for from the factory, it would be a field installed control to match the secondary load piping scenario. The primary boiler loop piping would operate at the fixed boiler HWS setpoint, but the firing rate would modulate to maintain above HWS setpoint as load is maintained on the boiler.

Storage is not necessary as noted in the brochure and in Heaterman's post #14 above, where the information about the boiler's preferred operating arrangenent is posted. Without storage, the control scenario would have to remove residual heat from the boiler in the off condition.

I know what to costs me to bid adding OAT reset to the conventional residential baseboard loads, and that was my inquiry. If the market was there for it or if I was bidding and building over the market, which I already knew the answer to.

I'm also wondering if lower load on the boiler could be maintained with VS fixed delta T pumping of the load loops and if that would be piped primary secondary, or directly on the boiler loop, how well the boiler could tolerate low flow (it may). Something to sort out with the factory and the installing contractors.

Congrats again on a great move.
 

heaterman

Minister of Fire
Oct 16, 2007
3,374
Falmouth, Michigan
With a BioWin you would likely be able to vary supply water temp from 130* or so up to maximum temp. This is simply based on how cold it is outside. The lower the outdoor temp the higher the water temp. What that does for you is keep the water temp in line with the actual requirements of the structure. In terms of actual burn or thermal efficiency is will not make much difference to the boiler but it will allow the boiler to run at a lower firing rate and maintain a more steady temp. This keeps your heating "system" on for longer periods of time which is better for comfort levels and reduces on/off cycle count like I was describing in post #14

As always we appreciate the information heaterman. I have a question regarding the Biowin actually cycling on and off less than an American style boiler. Do you believe that the less frequent cycling will actually lead to the parts in the Biowin lasting longer and a longer overall life for the boiler? Having experience with the unit I'm just curious what your take as to what the expected maintenance intervals and boiler life will be.

Thanks


Absolutely. Let's think about just one component that "works" each time the boiler cycles on/off. The ignitor.
Now think about wear and tear on it cycling maybe 3-5 times per hour as opposed to 3-5 times per day. Make sense?

If I understand how mine was working last winter, each time it started it went through the entire sequence of running the ash augers, the flue scraper augers, purging the combustion chamber, etc. before actually feeding pellets and hitting the ignitor to start the fire. If you reduce the number of cycles on all of those components they will simply last longer. Everything has a design life and a boiler is no different. The ability to ramp the burner up and down is built into the Windhager specifically to reduce the cycle count and also increase efficiency. It does indeed make a difference. Virtually all gas fired boilers built now have this capability for the same reason.

Another way to look at it is this........Think about how you would operate your car on a 50 mile trip if it ran in an all or nothing, on/off mode. You would start out down the road at wide open throttle and hold it pinned to the floor until you reached maximum speed (temperature in a boiler) Then you would turn the car off and coast until you needed to get going again. Repeat incessantly until you reach your destination. (desired room temperature)
Now, introduce a modulating burner (engine throttle) into the equation. The car accelerates up to a given speed (temperature) and stays there regardless of going up hill or down by varying the amount of fuel fed into the engine (burner). Your fuel consumption is far less now than when the car (boiler) operated at only two settings, wide open and off. Same thing happens with the boiler along with maintaining more even temperature.


A little anecdote regarding life of the boiler......I asked one of the techs at Windhager what the life expectancy of the BioWin was expected to be. Without any hesitation he responded "15 years". I thought it kind of odd that he was able to fire that back at me so quickly so I asked him how he could be so sure. His response told me a lot about how they think. He said simply, "That is how long we have made that model. Next year it will be 16."
Of course there are variables introduced by things like maintenance and care, water quality, overall installation, electrical problems etc etc but I thought it quite telling that he was unwilling to go beyond what actual field experience had demonstrated the life of their product to be. Regardless of what their lab results had been.
 

heaterman

Minister of Fire
Oct 16, 2007
3,374
Falmouth, Michigan
Well I looked at the internet literature, the brochure, and what I could gather is the boiler is not condensing rated (as expected) and has a turndown ratio in the range of 3 to 1. It is absolutely not a condensing boiler. Nothing wood fired should be due to the sheer nastiness of the consequences. It is a 3:1 turndown. The BioWin260 will go from about 90,000 down to 30,000

What this means is OAT reset of the HWS would not be an internal to the boiler electronic feature like it is with a gas condensing boiler. It would have to be implemented externally as a primary secondary piping with OAT reset of the secondary load loop piping. That is, it is not a feature you would wait for from the factory, it would be a field installed control to match the secondary load piping scenario. The primary boiler loop piping would operate at the fixed boiler HWS setpoint, but the firing rate would modulate to maintain above HWS setpoint as load is maintained on the boiler. As I understand it the Outdoor reset will be integrated directly into the boiler control.

Storage is not necessary as noted in the brochure and in Heaterman's post #14 above, where the information about the boiler's preferred operating arrangenent is posted. Without storage, the control scenario would have to remove residual heat from the boiler in the off condition. Post purge of heat. The boiler pump usually runs until the water temperature is down to a predetermined level.

I know what to costs me to bid adding OAT reset to the conventional residential baseboard loads, and that was my inquiry. If the market was there for it or if I was bidding and building over the market, which I already knew the answer to.

I'm also wondering if lower load on the boiler could be maintained with VS fixed delta T pumping of the load loops and if that would be piped primary secondary, or directly on the boiler loop, how well the boiler could tolerate low flow (it may). Something to sort out with the factory and the installing contractors.The Windhager control incorporates low temperature protection as standard equipment right out of the box. The boiler pump is off at anything below 122*
 

__dan

Feeling the Heat
Oct 5, 2011
331
Thanks for the reply HM.

OAT reset directly on the boiler is the easiest and least costly way to implement. It is a very desirable feature, a competitive necessity (imo). The factory should be able to implement directly with the existing burner control logic, software and an outdoor thermistor.

I've put more than few HeatTimer OAT reset controllers on large cast iron sectional boilers for schools. Modulating HWS by directly controlling the firing of the burners. The HeatTimers have an operating low limit setting to maintain HWS above condensing temp. Modulating down to 130 or 140 F is great for HW baseboards and a big operational efficiency gainer.

I get some condensation in the outdoor stainless flue from the Froling. It dripps out the cleanout tee and made a small ice mound last winter, clear to yellowish. The condensate from wood gasification burners looks manageable. When the market matures and becomes more competitive, more volume, I'm expecting condensing, modulating, pellet boilers in the future.

It still blows my mind that the gas crisis was in 1972 and the industry still has some waking up to do.
 
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