Magic Heat Reclaimers?

 
Rigar
Member
Posts: 856
Joined: Tue. Dec. 04, 2012 6:30 am
Location: central new york (syracuse area)
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice

Post by Rigar » Sun. Jan. 27, 2013 12:39 pm

Richard S. wrote:Two problems I see with the hear reclaimer. A) you have a fan running $$$ and B)if you are only using it half the year how long before the corrosion kills it?

I have to wonder if something like this would be more effective, It's passive and the corrosion issue goes away.

**Broken Link(s) Removed**
...thanks Richard
...good points
maybe my stack temps don't justify one....idk


 
Rigar
Member
Posts: 856
Joined: Tue. Dec. 04, 2012 6:30 am
Location: central new york (syracuse area)
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice

Post by Rigar » Mon. Jan. 28, 2013 8:01 am

Coalkirk....
what diameter flue pipe do you have?
approximately how much (length) of exposed flue pipe is available before it enters your chimney?

 
User avatar
coalkirk
Member
Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Mon. Jan. 28, 2013 8:21 am

My flue is 6". I've got maybe 3' of pipe to work with. I was hoping someone was already doing it and could take some before and after the heat reclaimer flue temp measurements. I can't afford to have my draft knocked down too much. Not a great chimney. I'm thinking if I do it, I'll put the heat reclaimer before the baro.

 
Rigar
Member
Posts: 856
Joined: Tue. Dec. 04, 2012 6:30 am
Location: central new york (syracuse area)
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice

Post by Rigar » Sun. Feb. 03, 2013 7:04 am

Coalkirk
...i havent forgotten about ya.. lol
what is your over fire readig?
Draft reading at breach?
Total length of (height) of chimney? ( to top)
temp (approx) of room the stove is in ?

...ive been calculating heat loss totals of exhaust gases...
the toughest part is getting a velocity reading of exhaust exiting the top of chimney...
Lotta math here!! lol

....im hopin to chart some rough numbers...but its the speed of which the gases travel which will be the biggest variable for most.
If your chimney is short it may not draft well if its cooled to much...(at least on paper..lol)

 
User avatar
Rob R.
Site Moderator
Posts: 17980
Joined: Fri. Dec. 28, 2007 4:26 pm
Location: Chazy, NY
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Chubby Jr

Post by Rob R. » Sun. Feb. 03, 2013 7:37 am

coalkirk wrote:My flue is 6". I've got maybe 3' of pipe to work with. I was hoping someone was already doing it and could take some before and after the heat reclaimer flue temp measurements. I can't afford to have my draft knocked down too much. Not a great chimney. I'm thinking if I do it, I'll put the heat reclaimer before the baro.
Before the Baro is the only place that makes sense.

 
User avatar
coalkirk
Member
Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Sun. Feb. 03, 2013 9:00 am

Rigar wrote:Coalkirk
...i havent forgotten about ya.. lol
what is your over fire readig?
Draft reading at breach?
Total length of (height) of chimney? ( to top)
temp (approx) of room the stove is in ?

...ive been calculating heat loss totals of exhaust gases...
the toughest part is getting a velocity reading of exhaust exiting the top of chimney...
Lotta math here!! lol

....im hopin to chart some rough numbers...but its the speed of which the gases travel which will be the biggest variable for most.
If your chimney is short it may not draft well if its cooled to much...(at least on paper..lol)
Overfire draft is about .2 and at the breach I have it adjusted to about .3 with the baro. Total chimney height is about 17'. The room the boiler is in stays nice and toasty. I never really took a room temperature reading there. So my chimney is short and for that reason this may not work out so well. When its firing hard, I've got a flue temp of about 400 below the baro and about 300 above.

 
Rigar
Member
Posts: 856
Joined: Tue. Dec. 04, 2012 6:30 am
Location: central new york (syracuse area)
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice

Post by Rigar » Sun. Feb. 03, 2013 9:12 am

Ok...thanks
i will see what I come up with
i will use my velocity as a baseline...and go from there
my stack is about 22 feet high
...i draft well @ 90 degree stack temps
..and after fireing hard rarely see 250 degrees...
I do experience poor draft when its 60-65 outside...as im basically at "idle"...and stack temp is so low

...i will get back on this
...for what its worth...i don't have alot of "wasted" BTU to reclaim....however you may be able to
...especially at 400.........maybe (educated guess) 3500-5500 btu/ hr


 
User avatar
coalkirk
Member
Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Sun. Feb. 03, 2013 10:18 am

Thanks! Once I get past fingers and toes, my math skills decline rapidly. :oops:

 
Rigar
Member
Posts: 856
Joined: Tue. Dec. 04, 2012 6:30 am
Location: central new york (syracuse area)
Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice

Post by Rigar » Sun. Feb. 03, 2013 10:23 am

coalkirk wrote:Thanks! Once I get past fingers and toes, my math skills decline rapidly. :oops:
.
......lmao

 
User avatar
stoker_RI
Member
Posts: 274
Joined: Tue. Dec. 28, 2010 2:01 pm
Location: Northern RI

Post by stoker_RI » Sun. Feb. 03, 2013 11:52 am

I had one once on a wood boiler...they are configured so that the flue temp needs to be 200 degrees for the fan to come on...Since your flue temps are not much higher than that, I question, once in operation, if the fan would come on, dissipate the heat, and thus cause the blower to cycle very often..also, how often is your boiler operating in a state where the flue temps are actually that high?

Another note: Mine was in a garage..I didn't notice if you said where your set up would be..but the fan is quite loud...if this is on an indoor stove..maybe near an area where a TV is or something? The noise of the fan steady, or worse, coming on and off, will drive you crazy

 
User avatar
stoker_RI
Member
Posts: 274
Joined: Tue. Dec. 28, 2010 2:01 pm
Location: Northern RI

Post by stoker_RI » Sun. Feb. 03, 2013 12:00 pm

another thing is, these things dramatically cool the flue down stream of the unit... on the wood boiler I mentioned, and keep in mind the fllue temps were much higher than what you are talking about, the flue had cooled so much that at the chimney temination, where I had a spark arrester, the elements along with ash actually glazed over the spark arrester mesh!..The flue temps were not hot enough at that point to melt it away!..and I totally lost my draft!

So..having said that..and thinking that your flue would be cool...doesn't that mean a loss of efficiency somewhere? Since a flue at correct operating temp results in the best efficiency?.....hmmmm

 
User avatar
SMITTY
Member
Posts: 12520
Joined: Sun. Dec. 11, 2005 12:43 pm
Location: West-Central Mass
Stoker Coal Boiler: EFM 520 Highboy
Coal Size/Type: Rice / Blaschak anthracite
Other Heating: Oil fired Burnham boiler

Post by SMITTY » Sun. Feb. 03, 2013 12:07 pm

Yeah, Stoker beat me to the punch. My father in law has one of those Magic Heat deals on his wood stove. The thing is BIG - alot bigger than it looks in the advertisement pics. Of course with wood, the thing is cranking all the time, so it works pretty good there. I don't think it would be worth the trouble at 300° stack temps .... and if you lose draft, that's another negative. I don't think it's going to put much heat out to justify it.

I recall reading a thread on here a few years back basically saying the same thing. Someone put one on their coal stove & it put out zero heat.

 
User avatar
coalkirk
Member
Posts: 5185
Joined: Wed. May. 17, 2006 8:12 pm
Location: Forest Hill MD
Stoker Coal Boiler: 1981 EFM DF520 retired
Hand Fed Coal Stove: Jotul 507 on standby
Coal Size/Type: Lehigh anthracite/rice coal

Post by coalkirk » Sun. Feb. 03, 2013 1:38 pm

From the units manual, the fan comes on at 150 degrees. It also says not to install the unit if you do not have flue temps of 280 degrees.

 
User avatar
McGiever
Member
Posts: 10130
Joined: Sun. May. 02, 2010 11:26 pm
Location: Junction of PA-OH-WV
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Hand Fed Coal Boiler: BUCKET A DAY water heater
Hand Fed Coal Stove: Warm Morning 414A
Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
Other Heating: Ground Source Heat Pump and some Solar

Post by McGiever » Sun. Feb. 03, 2013 2:07 pm

Me thinks the 280*F number is factored for creosote condensing from a wood source. So, not an issue w/ coal.

You could install this for your coal source...it only runs when it is hot enough and otherwise does little other than radiate some heat.

The return on investment will not be the greatest, though. Might have to save a couple tons of coal till you would break even. :)

 
User avatar
stoker_RI
Member
Posts: 274
Joined: Tue. Dec. 28, 2010 2:01 pm
Location: Northern RI

Post by stoker_RI » Sun. Feb. 03, 2013 2:22 pm

McGiever wrote:Me thinks the 280*F number is factored for creosote condensing from a wood source. So, not an issue w/ coal.
These units inside have several tubes running accross it...essentially an air to air heat exchanger.. What you say about creosote condensing may be true, but I think, using this with coal, these tubes would build up and collect fly ash in no time, thereby quickly making IT less efficient as well, and a constant çlean out chore...

Not worth it in my book...I ended up selling mine to a friend who has an Indoor wood stove, and he loves it!...Thats where they make sense..In a situation where you have a long, hot fire...
In a wood boiler, that is not the case, as the Being a boiler, the fire is not always roaring..it is regulated by a damper of some sort depending on the demand for heat...


Post Reply

Return to “Coal Bins, Chimneys, CO Detectors & Thermostats”