OWB Shelter...

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VAfarmer38

New Member
Aug 31, 2015
66
Central VA
I'm looking to build a shelter around my OWB to help the efficiency. I've noticed that on cold windy days/nights, it really affects the furnace in a negative way. I'm not looking to fully enclose the furnace, mainly looked at putting up a 3 sided slant roof shed to shield it from most of the elements and have a place to store some wood and stay out of the weather while loading it. I understand I'll need to extend the chimney through the roof of the shelter. Our wind is mostly from the West, Northest. Has anyone done anything similar and noticed any improvements? Does the longer chimney negatively affect the burn rate? Thanks.
 
In either case the wind is going to be an issue.

A taller chimney will increase the boilers draft.

Is your boiler a forced draft boiler or a natural draft boiler???

A windy day is going to increase the pressure gradient in
your OWB in all cases whether its a natural draft or forced
draft boiler.

You have to plan on securing your chimney extension with
guy wires to the roof.

A better option would be build a single flue tile lined block
chimney equal to the chimney size of your OWB and extend
an elbow to a clay thimble in the single flue tile lined chimney.

If you filled the boiler half full of fire brick as I did with mine you
can build a smaller hotter fire and lose much less smoke.

Ideally having more hot water storage is the ideal as you can
build a small hot fire, maintain the fire and make many hundreds
of gallons more of hot water with fewer burns during the week.

The taller the chimney the better the draft in any case.

The bigger issue is the smoke coming out of the loading
door when you reload it if you do not have a bypass flue in the boiler.

For what its worth, I filled my indoor wood and coal boiler half full
of firebrick and it is a huge aid in my burning wood and coal as the
firebox was hotter at all times and I had much less smoke lost up
the chimney as the fire is much hotter.
 
Forced air unit. Heatmaster MF5000. I'm wondering if I shield the unit from the wind itself if it will help to maintain water temperature better. I've heard of people adding insulation to the units but I'm not crazy about that idea. My OWB is completely exposed right now. Just thinking that putting it in a shelter would alleviate some heat loss from being exposed to the elements.
 
Forced air unit. Heatmaster MF5000. I'm wondering if I shield the unit from the wind itself if it will help to maintain water temperature better. I've heard of people adding insulation to the units but I'm not crazy about that idea. My OWB is completely exposed right now. Just thinking that putting it in a shelter would alleviate some heat loss from being exposed to the elements.
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I will help somewhat but if you use the firebrick like
I did you will save plenty of wood an have a hotter
smaller fire.

You should look at adding more water storage to enable you to
conserve hot water by adding more water storage.

Using a bypass loop will also save fuel by telling your boiler
its satisfied more quickly with a smaller fire too.
 
If you need to significantly extend your flue, look into a triangle shaped tower like you would see for a radio or TV antenna.

My neighborhood is heavily wooded with mostly mature oaks. 90 acres was divided into 14 lots in the mid 90's, smaller 2 acre lots along the road with larger 10 - 15 acre flag lots in the rear.

My rear neighbor has an '04 outdoor boiler. He bought it used and installed it in '11. The town building inspector signed off on the plans, but never actually bothered to inspect the site.

Another neighbor to the north west lives in a valley. She called the DEEEP on him in July '14 for supposedly "burning garbage" in his boiler on Memorial day weekend. Yeah, she waited 6 weeks to file a complaint. The problem was that the boiler in question had been shut down for 4 weeks when the infraction supposedly happened. DEEP didn't care about that. They issued him an infraction for violating a state ordinance that went into effect in '06 and told him to cease operation until his flue was extended to terminate higher up.

He ultimately had to extend his flue from 12 feet to approx 45 feet, so that it terminated higher than the nearest neighbors roofline. The flue had to be higher than anyone's roof peak who was within 300 feet of the boiler. My roof happened to be higher, but I am 325 feet away from the boiler.

The kicker was that his original flue was already significantly higher than the roof where the complaint came from.

Anyway, he installed a triangle shaped tower and has the flue pipes strapped to it.

We rarely smelled anything to begin with. Last winter was no different, hardly any smell, ever.
 
do not vent that boiler into a masonry chimney.
extending the chimney for draft reasons can lead to overfire conditions and overheating conditions. and the masonry chimney will tend to lead to creosote buildup. an additional piece of class A on the chimney will be fine. extend to 3' above anything within 10 feet. and is easy to clean when it needs it.

don't install a bypass loop.

we have a lot of people around here install one of those sheet metal/metal tube carport structures, and just set the stove outside one end of it.

if you have to extend the chimney, make sure everything is working properly, like your stove door gasket and ash drawer gasket, solenoid and damper in the back of the stove.
 
do not vent that boiler into a masonry chimney.
extending the chimney for draft reasons can lead to overfire conditions and overheating conditions. and the masonry chimney will tend to lead to creosote buildup. an additional piece of class A on the chimney will be fine. extend to 3' above anything within 10 feet. and is easy to clean when it needs it.

don't install a bypass loop.

we have a lot of people around here install one of those sheet metal/metal tube carport structures, and just set the stove outside one end of it.

if you have to extend the chimney, make sure everything is working properly, like your stove door gasket and ash drawer gasket, solenoid and damper in the back of the stove.

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He wants to limit the high wind exposure he has to the boiler thats why he is
looking into this as the boiller is nothing more than a radiator exposed to
the wind now.

Why should he not install a bypass loop??? if he has 3/4 pex he can only
pump 4 gallons per minute of hot water through his heating loops anyway
to heat his home effectively.
.
 
I think this thread is going places the op never asked about? Vafarmer this link https://www.google.com/search?q=out...X&ved=0CB0QsARqFQoTCJXxkK-m3ccCFULPgAodXOwKxA will show some pics of what others have done. Karls advice about a short piece of stainless pipe to get a little height makes sense to me too. We have a 35' height limit here on anything, so a guyed mast or factory type smokestack would never fly. Without a zoning variance that is. I believe any shelter you put above & around that unit will be worth a million to you when it's 35F and pouring rain.
 
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I think this thread is going places the op never asked about? Vafarmer this link https://www.google.com/search?q=outside wood boiler shelter images&biw=1740&bih=1003&tbm=isch&tbo=u&source=univ&sa=X&ved=0CB0QsARqFQoTCJXxkK-m3ccCFULPgAodXOwKxA will show some pics of what others have done. Karls advice about a short piece of stainless pipe to get a little height makes sense to me too. We have a 35' height limit here on anything, so a guyed mast or factory type smokestack would never fly. Without a zoning variance that is. I believe any shelter you put above & around that unit will be worth a million to you when it's 35F and pouring rain.
Thanks man, I appreciate the insight of others but I was a little lost there. I'll give that link a look. The main reason for the shelter is to keep the unit from being exposed to the cold wind (mostly) and keep me from being exposed to the pouring cold rain when I'm filler her up.
 
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He wants to limit the high wind exposure he has to the boiler thats why he is
looking into this as the boiller is nothing more than a radiator exposed to
the wind now.

Why should he not install a bypass loop??? if he has 3/4 pex he can only
pump 4 gallons per minute of hot water through his heating loops anyway
to heat his home effectively.
.
Leon, what exactly do you mean with installing a bypass loop? This is new to me.
 
Leon, what exactly do you mean with installing a bypass loop? This is new to me.

I wouldn't worry about it. If your OWB didn't come with that built-in, it likely doesn't need it.

(Although if your return temps are constantly much below 140, you might want to think about something like that to reduce creosote buildup in the box).

Shelter would do you good. My neighbour made a sort of one where his is - I think he just fastened some 2x lumber stuff to nearby trees (OWB is surrounded by big maples) and covered it with roofing steel. It makes a big covered area, and his whole winters wood is under there. Ideally if you could get it sheltered enough that it would retain some heat in there with your wood - that would be even better, as your wood would not only be out of the elements but also dry pretty good as the winter went on.
 
Leon, what exactly do you mean with installing a bypass loop? This is new to me.


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A( bypass loop) diverter valve does one thing it takes X number of gallons per minute
from the line delivering the hot water to the heating load/loop and returns
it to the return line in the base of the boiler to keep the boiler hotter and to
reduce thermal shock.
 
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I have no idea what the return temp is. I'm sure I could get a meter and check it. I have a display on the side of the unit that allows me to set the temperature and then it gives a reading on something (not sure if it's the return temp or the temp of the water jacket)
 
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