Stove Pipe

[5030]

At today's inflated prices, anything you heat with will be expensive...anything.

 

[ruffdog]

I have a 30,000 BTU propane modine type heater near the ceiling of my 2 car garage. Even though the garage is fully insulated, it would take a day to fully heat it up to 60 F deg. The two garage doors and concrete floor really sucks the heat out. The nice thing about the modine is you just turn it on when needed...easy peasy.

 

[CalG]

Neighbor in damp and humid Olympia WA has a complete shop and the wood stove always fired and the shop is very dry but he is retired and in the shop 7 days each week.

He has all the wood he can use for the sawing and splitting.

He told me he couldn’t imagine not having wood and paying for electric in retirement.

wood is good!

 

[ultrarunner]

wood is good!

North America’s abundant natural resource endorsed by President Carter with tax incentives…

 

[CalG]

North America’s abundant natural resource endorsed by President Carter with tax incentives…

And OH SO Carbon neutral!

 

[ultrarunner]

And OH SO Carbon neutral!

Yep… rotting in the forest or up in flames due to a wild fire or keeping the hearth warm on a cold winters night…

 

[5030]

If keeping your butt warm when it's cold out, 'carbon neutral' is the last thing on my mind. In fact, it's dead last anytime.

 

[WinterDeere]

While the condensation was not the direct fault of the heater (it's more due to the difference in temps between outside and inside without proper insulation, vapor barriers, and airflow), it still was a problem.

@ponytug already alluded to this, but the condensation actually is "the direct fault of the heater". Each gallon of kerosene burned produces something like 1.3 gallons of water as a byproduct in its exhaust. Hard to believe, if you're not a chemist, but true. While folks heating their homes with kerosene space heaters in the 1970's probably loved this aspect, free humidification, all that added water is going to cause condensation the next time you let the temperature drop in that space.

My new idea and project to start soon is a pellet stove.

Good choice. Just be aware of the cleaning requirements, and the various issues of different brands. hearth.com has a whole pellet stove forum, and reading through the issues guys seem to have with various models there, I'd be looking first at Harmon.

Pricing stove pipe, the cheapest I have found so far is $350! And that is just the pipe, no other parts like elbows or the cap, etc. This is the DuraVent 4in x 36in chimney stove pipe at $35. (30/3x$35=$350). I'm not even sure if this is the right size pipe! Do I need to step up in size to run that length?

Length dictates static draw, diameter dictates flow. Generally, taller is more of a problem with over-drafting on modern low-flow stoves, as these stoves are typically designed for worst-case min draft. When dealing with wood stoves, those of us with taller chimneys actually have to restrict them down to behave more like a shorter chimney, rather than step up.

And yes, quality pipe is not cheap.

It's actually better to have single wall pipe in the inside of the occupied space since you get more heat that way.

Not since at least the 1990's. This advice comes from older (think 1970's) wood stoves, that threw damn near half their heat up the chimney, and there were cases where you could take heat off the pipe without too much penalty. There were even special heat-exchanger stove pipes designed for this purpose. In many cases where too much heat was removed, they caused massive creosote deposition problems, and eventual chimney fires.

The exhaust from any wood or pellet burning appliance carries both water vapor and compounds that when condensed will deposit creosote. If you allow the exhaust gas temperature to drop below 200F before it reaches the top of your chimney, you are likely to experience this problem, as that's near the condensation point of water at typical reduced chimney pressures.

Older stoves kept chimney temperatures so high, that yes... you could take a good bit of heat off the chimney and often still stay in this safe 200F+ range at the top of the chimney. But the old stoves were only throwing this much heat up the chimney because they had absolutely terrible efficiency.

Modern stoves are much more efficient (80%+), and thus exhaust gas temperatures are much, much lower. And the lower you run the stove, such as using a low setting when you're not actually in the shop, the more you're flirting with this. So, if your stove manufacturer recommends double-wall or insulated pipe, this is the reason why. Using any mechanism to remove more heat from the exhaust can lead to creosote deposition, and even chimney stall and CO into the structure. And since you mentioned having a taller chimney, this problem is amplified, as the exhaust has even more time to cool on its long way to the top. Don't do it.

 

[HawkinsHollow]

@WinterDeere Some food for thought there! Excellent info! Thanks

 

[5030]

I'd be looking first at Harmon.

Keep in mind that Harmon is by far the most expensive solid fuel burning units on the market today and far as I know, none of them are corn biomass capable.

In my opinion, Harmon's are pretty units but I'm not into pretty, I'm into functional and all of them basically do the same thing and that is rapid oxidation of a solid fuel source and produce heat and all of them must be at least 80% efficient or again they cannot be sold domestically.

I've been using biomass stoves as supplemental heat for over 30 years now so I'm very experienced with it. I own 3 units, all corn (biomass) capable and they are all 100% solid state (computer controlled) and they all run on remote thermostats as well. Strictly for supplemental heat and I'd never consider them as a primary heat source, simply because the cost of manufactured pellets today is prohibitive and I frequent all the biomass forums and have for decades.

I need to add something of importance and that is...

There are only 2 manufacturers of pellet / corn venting, Simpson Duravent and Selkirk Industries and always keep in mind that they DO NOT interchange. Each manufacturer uses their own proprietary interlocking design so you CANNOT mix them successfully as they won't interlock with each other and both are expensive because the design on pellet venting entails a stainless inner liner with a defined air space between the stainless inner and the galvanized outer shell. All pellet venting has to be UL approved and certified by Warnock-Hershey testing labs or it cannot be sold in this country.