Questions on fresh air intake on pellet insert

[kh395269]

Hi Everyone,

I had at least one chimney guy that I called yesterday tell me that he wanted to put two stainless 4inch pipes up my chimney (one for fresh air and the other one the vent). He wanted to charge $800 just in supplies. As little as I know about a pellet stove, I thought this was ludacrous. First off, I know that since my chimney is only 15 feet, I can use 3inch pipe which should save some money right there. But my question is, how do you do the fresh air intake? I am still not clear on this. For those of you with pellet inserts, where does yours take the air from and what did you use to get the air. I thought perhaps you can use the ash dump possibly, but doesn't the unit prevent you from opening the ash dump? The Napoleon fresh air kit looks short and very different than the venting pipe. Also, of concern to me is how do you wire the thing. I have outlets one either side of the fireplace at this time. Am I going to be able to just plug it in there? Sorry for all the questions, but I am a newbie at this. Still waiting on delivery of my stove - next Tues or Wed hopefully. Thanks.

 

[rap69ri]

When we installed my parents we did not use any fresh air intake. The stove works great, and pulls air from the room not the chimney since the chimney is blocked off with a piece of sheet metal. The house is older so it's not that tight.

What does your manual tell you to do? Is it a requirement per the manufacturer?

 

[kh395269]

Hi, The manual does shed a little light on the subject, but still doesn't specify the best way to set it up. My house is an older home (1956). It has newer windows, but I would not consider it airtight by an means. I know I definitely don't want a hole drilled anywhere through the chimney

From the manual:

Outside air must not be drawn from an enclosed
space (garage, unventilated crawl space).
Note: Napoleon strongly suggests using outside air
for all residential installations, especially for those
that are energy efficient, air-tight homes.
Outside air supply must not be over 15' long.
Outside air vents must be made with 1 3/4" diameter
or larger metal or aluminum duct with a metal screen
attached to the end to keep out rodents (P.V.C. or
other materials may not be used).
The outside air inlet must not be above or within 12"
of the chimney termination, must have a rain cap or
down-turned elbow to prevent the water from entering
and be located so that it will not become plugged
by snow or other material.

 

[kh395269]

What could happen if you don't have one anyway?

 

[rap69ri]

So the manufacturer recommends but does not require it. I would give it a shot without the OAK and if it burns properly leave it alone.

As far as what could happen; I'm not an authority on this matter, but I would think that the stove would not burn very well if it truly needed outside air.

 

[Ruddmeyer]

Hi! I have a Lopi Yankee Bay insert and currently not using fresh air intake and the stove runs just fine. My home is an older log cabin so air is not a problem, I would try room air first and see how it burns before going for the additional expense. Good Luck with your new stove.

 

[Czech]

In my semi informed opinion, all stoves are happy to get combustion air anywhere, whether it be from inside your house or not. The difference is, drawing combustion air from inside your house pulls air out of your house (out the exhaust to outside), rather than pulling air from outside. On a tight, well sealed house, esp with other air drawing appliances (water heater, gas dryer, etc), without a OAK you may be creating a negative pressure inside your house. Depends on how tight your house is, either way will work, one or the other may work better, but drawing outside air and having it go back outside without sucking air from the inside is better IMHO.

 

[Shooter]

I have the Quadrafire CB1200i and havent used a fresh air intake at all. The stove runs great. As far as the living quarters needing fresh air....you get plenty of that with the common opening of doors which is plenty. I'm sure others wouldnt want anything but a fresh air kit but for me I'd rather save the money. Ash pan for mine is accessible from the front. Air comes in on the right side and directly up through the holes in the firepot to cause a swirling, turbo motion.

800.00 in materials sounds pretty high. My exhaust is 3" Chim-flex and runs 13ft to the cap. Piece of cake. There is a flange/thimble that seals the opening....this is a propane direct vent setup that I removed for the pellet stove. The 3" flex snaked right up the flue from inside. I paid 310.00 for the complete kit w/25' of pipe.

 

[ssupercoolss]

no, you do not have to have a fresh air kit. but it does help to actually keep the house warmer. without fresh air you will be pulling cold air into your house for combustion. this outside air will come in from the gaps in doors, windows, etc, using the "path of least restriction". which means you could be pulling cold air in from the most opposite corner of your house, actually causing a draft. i am a firm believer that cold air intake does work. i just have mine piped over to a window with pvc, secured through the window with a 2 X 4 that the window is sitting on. its not the prettiest, but it gets the job done.

 

[Shooter]

no, you do not have to have a fresh air kit. but it does help to actually keep the house warmer. without fresh air you will be pulling cold air into your house for combustion. this outside air will come in from the gaps in doors, windows, etc, using the "path of least restriction". which means you could be pulling cold air in from the most opposite corner of your house, actually causing a draft. i am a firm believer that cold air intake does work. i just have mine piped over to a window with pvc, secured through the window with a 2 X 4 that the window is sitting on. its not the prettiest, but it gets the job done.

Something to consider.....if you have a newer home with a high-efficiency furnace and (propane/ng) hot water tank you most likely will already have the fresh air compensator built in to the system. We have one downstairs. Fresh air is on-demand in this case and the air kit shouldnt be needed for the sake of equalizing combustion air pressures.

Add to that the regular coming and going out the door....and if you have pets that go outside....it's just not needed in these cases. And these are the homes that are usually well sealed.

 

[muss]

Home built in '56, i certainly wouldn't worry bout outside air intake . Like the fellas said , try it without & see before you drop that kind of $$$ . My home is only 3 years old & fine without one . Good luck & keep sharing your ??'s & input as we all need each other ;-) , Muss

 

[Shooter]

Not to mention that you can build your own cold air kit from the hardware store for a mere slice of what they will charge you for a factory kit. It's not rocket science.

My CB1200i has a little air intake "nozzle" or port and when the stove is running on medium burn rate I can barely feel any vacuum being generated. If anyone has a gas range they will most likely have been pulling more combustion air from their ovens than what an intermittent burn cycle from the pellet stove will use. Just a few non-scientifically tested thoughts.

disclaimer: your use may vary

 

[kilarney]

I'm sure others wouldnt want anything but a fresh air kit but for me I'd rather save the money.

How are you saving money if you are pulling air in from the outside? I know all houses leak, but keep in mind that pellet stoves have fans that blow air right out of your house. That air has to be replaced with outside air if you don't have a direct vent kit.

 

[Shooter]

I'm sure others wouldnt want anything but a fresh air kit but for me I'd rather save the money.

How are you saving money if you are pulling air in from the outside? I know all houses leak, but keep in mind that pellet stoves have fans that blow air right out of your house. That air has to be replaced with outside air if you don't have a direct vent kit.

Maybe I didnt give a good explanation of the bigger picture (my fault)......

Consider all of the "fresh air intake" coming into the home via the coming and going of the household. Got kids? Pets? Then you have multiple moments of fresh air intake. If you have a newer home you already have a pvc pipe that runs from your furnace location to the outside of the home.

And again....the same question should apply for gas ranges, do any of the manufacturers suggest fresh air kits for these?

I know it's an argument and one I refuse to be emotional over but I just dont see the payoff or the need being critical. Now, if the suction becomes so great that my eyeballs are protruded when I look in the bathroom mirror first thing in the morning I'll be reminded of this thread

 

[ssupercoolss]

theres kind of 2 different senerios here. like i said before, you do not need a fresh air intake on your stove. the reason i say that is because i do believe there is enough fresh air being introduced into any home by opening doors and whatnot, as stated above its not going to suck the wallpaper off of the walls. but....the efficiency of your stove will go up if the stove uses outside air, there is really no debating this, its a fact. think about it. which is more efficient, using air from inside your home, that you just spent money to heat, that will be replaced by cold air from the outside, or using air from the outside that you didnt already heat. onr thing you need to understand about my stove though. i dont run my stove "intermittantly". its not a decoration, its primary heat for my home. keep in mind i didnt spend but 20 bucks instaling my fresh air. i did notice after installation more even heat dispersion between the different rooms in my house. i hope i am explaining this correctly, or maybe its just confusing to some. a fresh air intake means the stove is burning outside air for combustion, its close to being a sealed system.

 

[sylvestermcmonkey]

Since I'm about to install a pellet insert I've given this a lot of thought and concluded drawing combustion air from a separate outside air intake would be nice, but not necessary. Certainly not worth $800.

First understand that pellet stoves and all other home heating appliances are heat exchangers. The air used to burn the fuel and the air warmed by the stove for your home are kept separate within the stove, otherwise you'd quickly have smoke in the house. This ought to be obvious but it seemed to me at least one poster appeared confused about this. To keep the terminology clear call the air carrying oxygen consumed in burning the fuel "combustion air" and the air that's warmed for your comfort "environmental air". The "combustion air" becomes "exhaust gas" in the firebox and goes up the flue, while the "environmental air" is drawn through the stove with a fan and circulated throughout your house as breathable air. "Combustion air" and "environmental air" don't commingle until becoming reacquainted well outside your house after which their amounts relative to each other and the rest of the atmosphere become meaninglessly small.

A gas-fired cooktop, to contrast this operation, does not separate combustion air sources or exhaust gases from mixing with environmental air. The products of combustion of natural gas are mostly water and CO2 so that's not much of a concern, although some people are more sensitive to this effect than others.

Second, you most likely already have appliances that draw air from within your home for their "combustion air". It might be an oil or gas fired furnace, clothes dryer, or water heater, but I'm not aware of any of them that have separate intakes for their combustion air. No one seems concerned about that, probably since most of them are in basements that draw air in from leaks where people don't usually feel them.

Third, think of your house is an enclosure. While most newer homes are designed to be relatively sealed from the outside, they're not pressure vessels, nor would you want them to be, otherwise you'd suffocate. Even if the pressure differential were as small as 0.05" Hg you'd lack the strength to operate your front door. Homes just need to be draft-free or you'd feel cold air wherever it leaked in. To burn fuel in your pellet stove, without a fresh air source vent, "combustion air" is drawn from within your home and goes up the flue as exhaust gas. Something has to replace the air that's removed from your home, so it leaks in from the outside. A fresh air vent just enables you to determine the source of this "leak".

Finally, remember that air expands dramatically when warmed. The volume of cold air drawn in from the existing leaks in your home for combustion is small compared to the volume of exhaust gas produced.

Since I already have an oil furnace, and don't perceive any problem with its use of use of environmental air as combustion air. I think the Napoleon manual is silly. I wouldn't be concerned about drawing combustion air from a garage, attic, living room, or basement. They're probably more motivated by liability concerns than anything else.

Think about it... a clothes dryer, even an electric one using no combustion air, probably draws orders of magnitude more air from within your home than a pellet stove ever could... and blows it right outside.

 

[sylvestermcmonkey]

BTW kh I'm going to investigate using my ash dump as a conduit for combustion air. I'll at least leave it open. The fresh air intake is in back of the insert, but I don't think attaching an intake pipe to it would be worth the effort. The ash dump cleanout is in the basement, and if my basement allows air to leak in from outside all the better, since there will be less of a need for outside air to leak into my living space.

 

[drizler]

My countryside ran just fine for 3 seasons with no outside air in a fairly small 1995 well insulated house. I just hooked one up a couple months ago from flexible aluminum 3 inch dryer vent and it works no better or worse than the inside intake. What will save you money in the long run IMHO is using a thermostat. My pellet and corn useage dropped noticeably since I hooked up a stat a couple years back by easily a quarter and probably more. Could be coincidence but I doubt it. I love the stainless many foot intake pipe thing. It sounds like a bill of goods someone would sell to the government for a big fat cost overrun contract.

 

[kilarney]

What most people seem to be ignoring is that a pellet stove blows combustion air outside of your home. Surely blowing air that had been inside air outside of the home with a powered fan is not nearly as efficient as a direct vent system.

 

[pegdot]

I've run my stove both ways, with an OAK and without one. Surprised me that the stove seemed to burn cleaner without the OAK hooked up but I soon discovered that running without the outside air caused a cold draft at floor level. After some investigation what I discovered is that the cold air leaking in around our old windows increased when running the stove without the outside air kit. The stove was actually pulling air from the outside into the house via the windows, in our case. The effect was to make the house colder so I hooked the OAK back up.

I think the phrase "fresh air" is confusing to some people. It's not a matter of fresh or stale. The stove doesn't care which it is but it's going to draw air from somewhere and if that air is from inside your house then you're lowering the air pressure inside your home and air from outside will find a way to move towards the lower pressure area inside. Nature abhors a vacuum. The old opening and closing the door argument just doesn't cut it unless you happen to leave your door cracked 24/7. If your house leaks then cold air is going to be drawn inside and if your house was really air tight then it would implode and collapse. LOL

Will your stove burn without an outside air hook up? Yes, but from an efficiency stand point it isn't the best way to go. Why would you want to exhaust air you've just paid to heat when you can use cold outside air for free? If I suggested to most people that they should run their bathroom exhaust fan constantly during the winter they'd tell me I was crazy. Is running your stove without an OAK really any different?

 

[kh395269]

Interesting the information on using less pellets with a thermostat. We put in digital, programmable thermostats for our oil heat, but I actually purchased a stove without thermostat capability. Some of the things I read said that because it take so long to bring a pellet stove up to optimal heating, it was not worth it to use a thermostat. I don't know which is better. I guess I'll see if I end up regretting my decision.

 

[Shooter]

Interesting the information on using less pellets with a thermostat. We put in digital, programmable thermostats for our oil heat, but I actually purchased a stove without thermostat capability. Some of the things I read said that because it take so long to bring a pellet stove up to optimal heating, it was not worth it to use a thermostat. I don't know which is better. I guess I'll see if I end up regretting my decision.

I love having the thermostat capability on my Quad CB1200i. Just set it and forget it. And to think I was going to buy a stove that didnt have one. Sure glad it's there. Of course, in our situation we dont need the continual burning. Even though it's primary heat for us this little insert kicks on and brings the heat up quickly when on the medium setting. Pretty handy.

 

[kilarney]

IIf I suggested to most people that they should run their bathroom exhaust fan constantly during the winter they'd tell me I was crazy. Is running your stove without an OAK really any different?

You hit the nail on the head. Most people say - "but your house leaks." Now I as you, which leaks more. A house with a fan blowing heated inside air directly outside or a house without a fan? The answer seems quite clear to me.

 

[RetireeBob]

Could you do a simple visual test to determine if outside air is needed? Close all doors and windows. Turn the stove up to at least a medium heat setting and observe the flame color and action. Open a window or door to the outside. If the flame gets more active or brighter, then you should install an OAK. If there is no noticeable difference, then an OAK is not required.