Barometric Damper Issues

Barometric Damper Issues

PostBy: Cool Customer On: Fri May 31, 2013 9:53 am

Am planning pipe setup for new install, and have a couple basic questions not clearly answered in reading other threads:

1) Where in the piping setup should the baro damper be located? Just above the elbow at flue? 18" above elbow (that's where stove manual specifies 0.6 - 1.0 " WC)? Other? Issues I've heard raised around this are ash buildup behind damper, safety risk if big puffback blows out through damper, excessive efficiency loss, etc.

2) Is it better to get a 22g tee and add a damper to it, or look for a 22g tee with damper pre-installed. Are there "baro-tees" designed to accept dampers, or do you get a plain tee and drill holes for damper installation? Recommendations on an adjustable, calibrated damper and tee would be welcome.
Cool Customer
 
Hand Fed Coal Stove: Harman Mark I

Re: Barometric Damper Issues

PostBy: VigIIPeaBurner On: Fri May 31, 2013 10:29 am

VigIIPeaBurner
 
Hot Air Coal Stoker Furnace: Keystoker Koker
Hand Fed Coal Stove: Vermont Casting Vigilant II 2310
Other Heating: #2 Oil Furnace

Re: Barometric Damper Issues

PostBy: franco b On: Fri May 31, 2013 11:37 am

You can locate the damper at any point in the connecting pipe. .06 to 1 is too high and will result in too high stack temperature as the high draft draws the heat out of the stove too quickly. .03 to .05 is more realistic. To combat excessive draft is the function of the baro and also will make the manual air intake setting more uniform in performance as draft varies with changing outside temperatures and barometric pressure.

The damper I have seen that comes with a tee has been the cheaper less sensitive Field model. The Field model RC can be bought with a collar so you do not have to buy a tee but will require you to cut your own hole in the pipe and strap on the collar, or you can mount it in your own tee. This model is sensitive but leaves a gap around the flap even when closed. More expensive models seal better.

A manometer is nice to have to adjust the baro correctly and also to monitor chimney performance. The Dwyer Mark ll model 25 is $35 on the Dwyer web site but can frequently found for less on Ebay. Buy new with all the fittings and oil supplied. Chimneys can vary quite a bit in performance and with the manometer you will know precisely how yous performs. What you are concerned with is if yours has a tendency under certain conditions to reverse.

Puff backs in hand fired stoves are almost always caused by loading a large amount of coal all at once and then closing down the air before the blue flames appear that indicate burning gas, Loading in two smaller layers is the safer way. In the beginning load in many layers to get a feel for just how your installation performs. Have patience and realize that coal responds to changes very slowly. Maybe write down in a log just what you are doing to help in the future. In time you will get used to the performance of the stove and will be able to service it much faster. Put a witness mark on the stove body and on the air control knob when fully closed which will help to repeat a particular setting and see at a glance just where it is set.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea


Re: Barometric Damper Issues

PostBy: Lightning On: Fri May 31, 2013 6:52 pm

I agree with everything that Franco described. Just to make it simpler, what he's saying is that by maintaining a consistent draft, you have consistent combustion air coming into the stove. This makes for a nice steady heat output thru the burn period (normally 12 hours depending on heat demand). Case in point - before I installed a baro, I had a hard time managing the heat output of my furnace (basically a hand fed stove with blowers to duct work). If I closed the combustion air inlet too much it would slowly cool, which made for lower draft in the chimney, which in turn made the fire run cooler even more till it was dying. If I opened the combustion air too much, it would grow hotter which created stronger draft in the chimney which would force in more combustion air which caused the furnace to run hotter still - you can see where this is going lol.. Too many trips to the basement to control combustion air :lol: ..

So after installing the baro, it regulated the draft to a consistent level usually .03 -.04 and I would get a 12 hour burn that would only vary by a few degrees with no fiddling. Love that 8-) ... The baro was a huge help for me!
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Barometric Damper Issues

PostBy: Flyer5 On: Fri May 31, 2013 9:38 pm

franco b wrote:You can locate the damper at any point in the connecting pipe. .06 to 1 is too high and will result in too high stack temperature as the high draft draws the heat out of the stove too quickly. .03 to .05 is more realistic. To combat excessive draft is the function of the baro and also will make the manual air intake setting more uniform in performance as draft varies with changing outside temperatures and barometric pressure.

The damper I have seen that comes with a tee has been the cheaper less sensitive Field model. The Field model RC can be bought with a collar so you do not have to buy a tee but will require you to cut your own hole in the pipe and strap on the collar, or you can mount it in your own tee. This model is sensitive but leaves a gap around the flap even when closed. More expensive models seal better.

A manometer is nice to have to adjust the baro correctly and also to monitor chimney performance. The Dwyer Mark ll model 25 is $35 on the Dwyer web site but can frequently found for less on Ebay. Buy new with all the fittings and oil supplied. Chimneys can vary quite a bit in performance and with the manometer you will know precisely how yous performs. What you are concerned with is if yours has a tendency under certain conditions to reverse.

Puff backs in hand fired stoves are almost always caused by loading a large amount of coal all at once and then closing down the air before the blue flames appear that indicate burning gas, Loading in two smaller layers is the safer way. In the beginning load in many layers to get a feel for just how your installation performs. Have patience and realize that coal responds to changes very slowly. Maybe write down in a log just what you are doing to help in the future. In time you will get used to the performance of the stove and will be able to service it much faster. Put a witness mark on the stove body and on the air control knob when fully closed which will help to repeat a particular setting and see at a glance just where it is set.



Just so everyone knows we do stock the 6" RC and 8"RC in black with the Tees. Alaska, and Reading also carry the same ones I believe so our dealers and theirs should also be able to supply them as well. It is nice having the black baro instead of the grey.
Flyer5
 
Stoker Coal Boiler: Leisure Line WL110
Hot Air Coal Stoker Stove: Leisure Line Pioneer