Effort to Improve Chimney Draw

We have always had problems in spring and fall getting enough draw from the outside chimney once we switched from wood to coal, constant puffing and CO alarm activation. The chimney was built in the late 70's to handle a Joutl Combi # 4 wood burner and did a good job. This fall I decided to try something that wasn't big $$'s, the stove pipe connection for the Hitzer is 6" so we figured we'd try an wind turbine on top of the chimney. I called the folks at Empire Ventilation in New Jersey and had quite a conversation and explained what I wanted to do - make an adaptor for the top of the chimney and affix a 6" wind turbine on it. They said no guarantee but it sounded like it had potential, they did say the turbines would not work with wood burning they get quickly clogged.
Fortunatly my workplace has a full sheet metal fab shop and I worked in that area for quite a few years before switching jobs so after taking some measurements we completed a SS adaptor to affix to the top of the chimney. As you can see in the photo there are quite a few trees around that don't help the situation.

Results - A definite positive the monometer shows definite improvement we have not had one CO alarm so far even the days when temps were in the high 50's. We get quicker response when it is time to reload the fire brightens up quick and the new coal ignites faster (have to be careful now). On dead calm days the turbine has stopped when the stove is running, but as soon as I open the ash door and the fire starts to build the turbine starts to really spin. Right now I am running the Hitzer without the hopper installed it is still too warm to really get rolling. Don't know how long the turbine will last it was recommended we purchase the SS model - have to say the folks at Empire were great I ordered it and had it in 3 days.

Nice job. The only worry I can see is corrosion from the coal exhaust even with stainless.

Shoulder months are always tough on effecient hand feds. My Buderus struggled when the air was damp and heavy. I did not run a barometric damper so I was pushing maximum heat up the stack. It still wasn't like when the cold weather rolled in.

It's really good to hear you had positive results with this. Thank you for letting us know. This could help a number of other people that may be in a similar situation. Keep us posted as to how well it continues to work and if you ever have a corrosion problem...

dj

How much was the turbine? I installed a draft inducer this season as the other options were too expensive.

Just to answer a few of the questions:
The stainless steel version of the Empire 6" turbine was under $160.00 they didn't clobber me on the shipping either, I thought this was an excellent price. I did notice other websites were selling the exact same turbine for $30 more, you can buy direct from Empire and they are really terrific to deal with.
Corrosion - This is my theory - Because of so many trees around our house we had down draft problems once and a while when the wind was out of the northeast. 20 years ago when we switched to coal I built a stainless steel chimney cap and it has been on the chimney until we put the turbine up. The cap look as good as the day I put it up there when we took it down. I believe because this new setup is always exposed to rain and there is no accumulation of fly ash to hold the "acid" aginst the stainless it should be OK.

duck, I had a galvanized turbine on my wood stove chimney for about 20 yrs & it also was still in great shape except for a little structural damage from hitting the ground when we had a mini hurricane come through a few yrs back. They work great, plus they are cool to watch--takes me back to the 60"s.

Great idea and very nice job on the fabrication!!! I think you will be just fine as far as corrosion goes, I seem to put much more stock into stainless steel/coal burning than most around here, but hey, what do I know!!!

Great job and thanks for sharing!!!

If the flue temperature is about 250 all the way there will be little condensation or corrosion.

The picture is after 2 years. You can see that the cap will have to be replaced in another 3 years or so. It is also why the last section is short for easy and less expensive replacement.

franco b wrote:If the flue temperature is about 250 all the way there will be little condensation or corrosion.

The picture is after 2 years. You can see that the cap will have to be replaced in another 3 years or so. It is also why the last section is short for easy and less expensive replacement.

My cap looked like that after one season. Perks of living in the wettest state in the US

What happens on really windy days? Would you get to much draft?

Op4_camper wrote:What happens on really windy days? Would you get to much draft?

I was thinking the exact same thing. It seems that draft induction would be required more on windless days, and less on windy days. This device however provides just the opposite.

Vrey good idea duck. Do you have a MPD on the stove pipe for these windy days?

Wouldn't hurt to clean the turbine blades with a toothbrush or similar, just to get the flyash buildup off (didn't look to see if you have hand fired or stoker - hand fired will have lots of flyash buildup) at the end of every season. If you keep up with it, it will last quite a while. Certainly longer than regular steel.

In regards to a few of the comments. As far as windy days, yes the turbine really winds up and I have gotten a lot higher readings on the monometer then before with out it, the stove is a Hitzer hand fired w/hopper I do have a MPD in the pipe. We replaced all the gaskets in the stove this year and I haven't had to regulate the MPD. On still days when the stove is idling there is no turbine movement as soon as the ash pan door is opened and the fire picks up the turbine starts to move and speed increases in relation to fire intensity. We definitely see an improvement the fire picks up quicker the new coal catches quicker and we haven't had a "PUFF" yet. In the spring we do plan to get up on the roof and inspect the setup and clean the fly ash from the turbine blades.