Outdoor Wood Stoves. Got one?

[Fish4Brains]

That is the size coil I was thinking of using. I have a 1800 ft house new construction with high ceilings. Heats pretty well. Maybee thats on the light side? Thoughts?
Thanks Brian.
Also I will post some pix later in the week of my stoves progress. Things are moving along well.

 

[ghitch75]

in Michigan you figure 50 btu's per square foot so for 1800sft you need 90,000 btu's

 

[Fish4Brains]

Thanks for the reply it looks like I had better bump it up 25% or so.
Brian

 

[Butch(OH)]

cbrslider what size coil do you have in your furnace?...i have found that the coils dealers are sell don't make the btu's thet say they do...like a 16"x18" with 3 rows of 3/8" tube only makes about 68,000 btu's at 180 degress and the dealers say 139,000 btu's...so if your boiler drops to 160 that would only make around 48,000 btu's...

Not questioning your facts but wouldn't air flow affect BTU output also? or not? I have yet to purchase my heat exchanger and this subject is of interest to me. The literature that came with my outdoor furnace suggests a need to speed the fan up. How does one determain airflow needs other than by best guess? As you suggested, my dealer implied that a few degrees in water temp would have a great affect not only upon the BTUs delivered but fuel usage.

 

[ghitch75]

faster fan speed will move more cfm and in turn cool the coil(water) faster and your out let temp drops your return water will get to low and you boiler will eat wood and not heat right...the way i size the coil for a house is by btu's per square foot and you need to know the gpm of the pump with head and line loss and the cfm you heating system will make...there is no just one size to fit all when it comes to coils...i have all my coils made to fit each job and that all depends on how the heating system was installed in the first place.....

the 16"x18" coil @ 78,000btu's is with 6gpm and 1200cfm with inlet temp of 70 degress F and 180 inlet water temp

 

[Fish4Brains]

Gitch, it sounds like you have some expirience with these systems. are you a reseller/ installer?
Maybe I could sway you to look over my system design when I get a little farther. The fella here in town that sells the stuff does not seem to sharp and he is so opinionated its scares me. I will be purchasing a pump aquastat and exchanger to name a few items in the near future.
Brian

 

[cbrslider]

"cbrslider what size coil do you have in your furnace?"

I don't understand what you are asking. I don't know anything about coils in my furnace. I have hotwater baseboard on my first and 1/2 story, then radiant in my basement floor. The outdoor boiler water comes from the boiler to a heat exchanger inside the house that is tied into my propane system(backup system?). I am lost when you talk about the coil. My heat exchanger is a 30 plate unit, if that helps.

The stove is supposed to put out 250000btu's and my propane unit is 115000btu's. So I should have more than enough outdoor boiler to heat my house.

Since we are on this technical stuff...should the primary loop pump run continuous 24/7 even when there aren't any zones calling for heat? The primary pump and the pump circulating the inside(from the primary loop water)water thru my heat exchanger both run constantly even now as I type this and it's 75degrees outside. I know that the pump from the boiler to the house is to run continuously but the other two pumps are running constant also.

Thanks guys.

Ray

 

[ghitch75]

heat exchangers and air to water coils are two different things...if i was hooking up yours cbrslider i would put a 3 way zone valve in the line going to and from the boiler(wood) to turn the water back to the boiler(wood) when your propane system is not calling for heat...as far as your pumps on your propane system do you have zone valves for each section of your house and the pumps are turned on with them?....if you don't want to run the pump 24/7 on your boiler(wood) you can run a 2 wire (18g) to a relay and kick the pump on when you system calls for heat...

 

[ghitch75]

Gitch, it sounds like you have some expirience with these systems. are you a reseller/ installer?
Maybe I could sway you to look over my system design when I get a little farther. The fella here in town that sells the stuff does not seem to sharp and he is so opinionated its scares me. I will be purchasing a pump aquastat and exchanger to name a few items in the near future.
Brian

yes to both be doing HVAC and boiler work for 25+ years and been doing wood boilers for the past 5 years and i can get any part you need( pumps, coils,piping,controls,ect) and yes i'll help you all i can

 

[Butch(OH)]

faster fan speed will move more cfm and in turn cool the coil(water) faster and your out let temp drops your return water will get to low and you boiler will eat wood and not heat right...the way i size the coil for a house is by btu's per square foot and you need to know the gpm of the pump with head and line loss and the cfm you heating system will make...there is no just one size to fit all when it comes to coils...i have all my coils made to fit each job and that all depends on how the heating system was installed in the first place.....

the 16"x18" coil @ 78,000btu's is with 6gpm and 1200cfm with inlet temp of 70 degress F and 180 inlet water temp

Again, please don't take this as questioning your facts or experience, I am trying to learn and here is my problem, I am trying to save a few bucks and do this myself otherwise i wouldnt be on the internet asking. Do I need to call upon a HVAC pro with all the wits and equipment to analyze my house and system? All of the stove dealers act like it's a no brainer, purchase X BTU coil, make it fit your duct, hook it up, adjust boiler temps so it works the best and uses least fuel and enjoy. I doubt that it is that simple but also wonder how far I need to go in complicating it.

To offer you some facts in my case my Hi-Ef natural gas forced air system icluding new ductwork was professionaly installed about 10 years ago and has operated with no complaints, fuel use or otherwise so I would assume ( I know bad thing to do) that the system was sized and installed correctly. Are you saying that in my case (assume proper air flows) that the still need to completly retest and calculate flows in order to get the exchanger right?

 

[ghitch75]

Butch(OH) try to size the coils to the cfm your system makes(the model # of your furnace will tell you that).. call the people you had install it and they can tell you and as far as the size of coil you need well depend on what btu your furance is and the cfm and the flow rate of you pump..line size is one of most importent things to get right don't run anything small than 1" to the house from the boiler...are you hooking your water heater to it too?....90% for the guys selling boilers have no HVAC training they go by rule of thumb and they make it sound like you just shove it in and it works not always the case....thats why we have heat loss heat gain calculartors to get it right.... it will all show it's self when it get down below 20df outside and you won't be warm and you can't get enough wood in the boiler....i'm not saying they are all like this just what i'v seen over the years...if you want to be happy with your system and to run as best as it can get as much info as you can so your not doing it twice........if you would pm me your brand for boiler and the of spec's of your system i could tell you alot more.

 

[cbrslider]

"if you want to be happy with your system and to run as best as it can get as much info as you can so your not doing it twice."


AMEN! Thats the best and only way to put it!!!! I thought I had enough information. I read about all the boilers and their designs, materials manufactured with, warranties, stainless vs. plate steel, etc. But there was more I didn't look into. Look into the lines underground, the material that is used to insulate the lines, the heat exchanger-water to water or water to air, pumps needed to get the hot water to the house, etc.

I wish I would have had all the information that I needed before I dropped the large sum of cash on a system that is not working nearly up to the speed that it should. I am going to have to dig up my lines and replace them along with re-wiring the system inside the house. All adding up to spending double on something that I should have only paid for once.

ghitch75- I have zone pumps(taco 007) on each zone in my house except the basement radiant floor(taco 0011)which is another fiasco in and of itself. Each zone kicks on when the thermostat in the room(zone) calls for heat. My concern is that the primary loop pump runs constantly when there is no call for heat in any of the zones, thus running down the temp of the primary loop due to the water constantly flowing thru 10-12' of uninsulated pipe, causing my propane to kick on. It is running as I type this and nothing has called for heat all day.

Thanks

Ray

 

[tawilson]

How about if you put a three way valve in the primary loop with an aquastat so if the temp drops below say 150F it just recirculates, bypassing your propane boiler? If I ever add a wood boiler to my oil boiler system I thought this work.

 

[MS-310]

Gitch, it sounds like you have some expirience with these systems. are you a reseller/ installer?
Maybe I could sway you to look over my system design when I get a little farther. The fella here in town that sells the stuff does not seem to sharp and he is so opinionated its scares me. I will be purchasing a pump aquastat and exchanger to name a few items in the near future.
Brian

What town do you live in, what dealer???? Im sure I would know them.

 

[Fish4Brains]

I am going to leave him out of the conversation. He has not done any wrong I just get nervous around people that tend to think if they make other products look like trash theres will have to look good. you know what I mean.

 

[Fish4Brains]

Posting pix of my stove so far.....well maybee
Just before the water jacket front

Finishing up the water jacket.

ready for hinges

My largest walley to date 13.5 lbs couldnt resist.

Any constructive criticism is welcome. I plan on running water in the door and insulating it as well.
Later Brian

 

[ghitch75]

nice job and fish too!....what do you think your water cap. is going to be?...are you going to have grates in the bottom?...as far as water goes anything less than a 100 gallons will cause to to cycle alot(and depending on load=btu draw)....if it cycles to much you can always add a couple 50 gallon water heater tanks to it for more cap.

 

[Fish4Brains]

230 gallons and thanks

 

[Fish4Brains]

Oh and no grates but probably forced air

 

[ghitch75]

forced air would be good make it fire up faster