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Heating incoming outside air

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by iceguy4, Jan 12, 2013.

  1. iceguy4

    iceguy4 Minister of Fire

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    What are your thoughts? Is it worth the hassle? anyone uning the selkirk system?
    Thanks in advance for your time

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  2. Don2222

    Don2222 Minister of Fire

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  3. P38X2

    P38X2 Minister of Fire

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    I'm assuming you mean heating the air going to your stove? Are you having problems with icing of your OAK on the inside? There was a post a couple weeks ago by someone with that issue. Was that you?
  4. iceguy4

    iceguy4 Minister of Fire

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    No. but I did rig a set up like the selkerk system. I have no way to measure its
    effectiveness...
  5. CtPaul

    CtPaul Burning Hunk

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    My new setup is pulling air from inside the chimney. So it should temper my intake air. That was really my best option anyway for my insert
  6. Wachusett

    Wachusett Feeling the Heat

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    I have wondered the same thing. I have been checking my stove with IR gun all season. During the recent cold snap we had I disconnected the OAK.
    The outside air was in the single digits. I check the stove in 4 locations (4 corners at the door). Without the OAK inhaling the frigid air the stove
    temp went up at each corner as did the temp on the vent pipe. Preheating the combustion air must be good thing. I have also heard on here
    many explainations of what temperature combustion occurs at and that the incoming air temp does not matter. However I think its fair to say that all the air
    pulled through your stove is not exclusively used for combustion.
  7. iceguy4

    iceguy4 Minister of Fire

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    My knowlage of oil burners and their set up has taught me air for the most part is 21% O2 (necessary for combustion) and 79% N (completely useless for combustion but needs to be heated just the same)
  8. Former Farmer

    Former Farmer Feeling the Heat

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    I have it installed on my Castile insert and my PB105 boiler. It works very well on the Castile. It leaves a little to be desired on the PB105. On the boiler, the vent cap and the last 3 feet of venting that are located above my roof, get a creosote build-up in them. The boiler will idle for quite a while sometimes and I think that the amount of fresh air that is drawn in, cools down the interior pipe too much causing the creosote formation. It takes a quite a bit of work in the spring to clean up this buildup.

    Is there anything a person can burn in a pellet boiler during the season to help this build-up of creosote?
  9. Don2222

    Don2222 Minister of Fire

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    Hello

    Did you OAK up your boiler? You must do that too, if you do your pellet stove!
    See my boiler pics with Carlin Air Boot!
    http://www.hearth.com/talk/threads/...-or-becket-burner-air-boot.52869/#post-664807

    The Boiler OAK is next to the Central Vac. Heck the Vacuum is Also vented outside! No sense getting all that dust that the filters do no catch blowing all over the place! ! ! !
  10. iceguy4

    iceguy4 Minister of Fire

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    I would agree with you Don...if my oil boiler came on...it dosent...as for my central vacuum...never thought of that. Now thats gonna be tricky. Heading to shop right now...if I take hair dryer hose...rig it to ...I'll figure something out...pic's to follow
  11. Don2222

    Don2222 Minister of Fire

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    Hey, that is an idea! The negative pressure in the bathroom created by the exhaust fan in the ceiling could very well be offset with an OAK on the hair dryer!

    Using a hair dryer may be a great idea to warm up that OAK air!! Good idea!

    How about this HotPod? Should do the trick!
    http://www.heatersplus.com/hotpod.html

    • Do you turn up your thermostat in the morning for the whole house…just to have a warm bathroom?
    • When you leave home for vacation during the winter months, do you worry about “what if” the furnace fails?
    • Do you want to keep the baby’s room at a warmer temperature, and the rest of the house cooler?
    • Now you can have a warm bathroom, a back-up system for the furnace and a consistently warm baby’s room.
  12. hoverfly

    hoverfly Minister of Fire

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    Preheating combustion air in automobiles and commercial power plants are common practices today. This increases the efficiency of fuel consumption and a reduction in pollution. The disadvantages is that in automobiles you no longer have the densest air possible to generate maximum horsepower. However with the advancements in technology does that really matter? Unless you are racing or need this extra power with a reduction of fuel efficiency, no it does not. Any residential high-efficiency boiler/ furnaces, combustion air is irrelevant because most of the heat is extracted for heating your home. This Is why some systems have PVC piping. But if you use a lesser efficient appliance, preheating combustion air will increase efficiency.

    Pellet stoves and boilers still require stainless steel piping because the output temperature of the exhaust is still hot enough to melt PVC. Therefore using the exhaust from the pellet appliance to preheat combustion air will reduce fuel consumption. Because you are increasing the temperature of the cold air, less energy is used to bring it up to combustion temperatures. Now some people may claim that the pellet stove works better, without preheating the air. However this is not true, though the flame may perform better, it is actually not burning at maximum efficiency. Again this is because it takes more BTUs to rise the combustion air to combustion temperatures, therefore consumption of wood pellets is actually increased.

    If you are having problems with condensation and icing it would be advisable to insulate your piping with appropriate fiberglass insulation that has an outer foil wrap. This will help with keeping the moisture from making contact with the venting. Now some systems may condense more often than others on several reasons. First is the length of the venting may be too short therefore not giving the air enough time to heat. Second it could be that no matter how much length of venting there is to heat the combustion air, the outside combustion air could be very cold. However the air still being preheated. Third, some pellet appliances can be more efficient than others therefore it could be a more common problem with the more efficient stoves. With a lesser amount of BTUs leaving through the vent, there is less to preheat the air. Last it also could depend on what setting you using and having a combination of the above.

    There is no advantage in pulling room air for you heating appliance. Again you are losing efficiency using more energy to make up the difference lost in preheating the combustion air. As a matter of fact this could be unhealthy with airtight homes as it produces a negative pressure. Therefore the combustion air should be drawn from the outside. One other thing there is a difference between actually preheating air and a system like the one above to compensate for negative air pressure in the home. Preheating combustion air requires something like what Selkirk's direct temp sells where combustion air is directed around the exhaust vent as a single unit.
  13. jtakeman

    jtakeman Minister of Fire

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    Using anything but natural convection to preheat the air wouldn't be worth it IMHO. Why pay extra using electric heating elements that cost $$$ to use?
    StihlHead likes this.
  14. hoverfly

    hoverfly Minister of Fire

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    In a retention flame oil burner, It is actually has to do with the fuel being too cold, what you get is called Puff back. The igniter is not hot enough to instantly lite the fuel therefore there is a delayed action before it does. Makes a loud bang and scares the crap out of yah. For any heating appliance there is no advantage in using an external preheating source for combustion air. Unless it is difficult for the fuel to light. When I had the oil burner myself it was cheaper to use an additive, nozzle line preheater, and number two home heating oil instead of the more expensive kerosene or mobile home blend.
  15. DBCOOPER

    DBCOOPER Feeling the Heat

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    Could you provide a reference for that statement?.
  16. hoverfly

    hoverfly Minister of Fire

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    [​IMG]
  17. jtakeman

    jtakeman Minister of Fire

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    I still won't pay to heat my incoming air. I would possibly use a multi-pass heat exchanger or something. No way I'd bother using electric heating elements.

    Sounds like using the selkirk system might be worth the extra cash.
    StihlHead and Mr. Spock like this.
  18. CT Pellet

    CT Pellet Minister of Fire

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    If you think about it, the up-front cost of the "air heater" coupled with the expense of the electricity.....If you need more heat, why not just spend a little extra on your pellets and buy great pellets? Penny wise and dollar foolish?
  19. iceguy4

    iceguy4 Minister of Fire

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    How did we get to paying to pre-heat the outside with electricity...was it my comment
    That was a joke about rigging my central vacuum with an OAK ...I'm so cheap I can hardly pay attention
    DexterDay likes this.
  20. DexterDay

    DexterDay Guest

    The Selkirk system would he somewhat beneficial. But a Very long run, especially external/outisde, will cause to much cooling of the exhaust gases and will cause, well, you know what to build up (Not Good :()

    When I replace the Quad (I know, I know, I did that last year) this year, I plan to use Selkirk DT. A simple 4ft vert inside, to 3 ft horizontal.

    But i wouldn't pay to heat the air. I'm doing it for the added convienence, and mainly for the looks. It looks just like 6" stove pipe :)
    mepellet likes this.
  21. DBCOOPER

    DBCOOPER Feeling the Heat

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    Guess I should go blow down my pellet stove...
  22. jtakeman

    jtakeman Minister of Fire

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    Don2222 hotpod?

    I'm so cheap attention has to pay me! :p
    iceguy4 likes this.
  23. SwineFlue

    SwineFlue Minister of Fire

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    Well, you can try this:
    http://www.hearth.com/talk/threads/took-one-for-the-team-csl-pellet-stove-cleaner.101029/

    However, from the Q&A on the CSL website: "Q) Can CSL be used in a pellet stove fireplace insert?
    A) NO!! you cannot use the CSL in a pellet stove. Pellet stoves are intended to produce very few smokes. However, it requires regular visual inspections."

    I assume that was written before they came out with the CSL pellets.
  24. iceguy4

    iceguy4 Minister of Fire

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    I'm laughing my but off.. good one!
  25. hoverfly

    hoverfly Minister of Fire

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    It sounds like you need to once in a while run it on high some how for an hour or so . You could add a dump circuit like some boilers have since they do not have an igniter. They just keep running all the time. This is to keep the house from getting to hot. The other option is to install some kind of mechanical or electrical bypass on the combustion circuit to keep the vent gas warm enough. But somehow you should not be generating creosote at all, even on low temperatures.

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