To OAK or not to Oak

There is nothing harder to open than a clenched mind.

That sounds like something Einstein would say. Pure genius

When warmer weather comes, and on a calm day, open the window closest to your clothes dryer 1/4". Now, light a piece of stick incense and hold it near the opening in the window. Maybe the smoke will drift out slowly, maybe it'll blow back into the room slowly, maybe it'll go straight up. Take note of what it's doing. Now, go turn the clothes dryer on and repeat the test. Wow, weird! Lots of air coming in! Where does that air come from when the window is shut? Ya, the same places it comes from when yer stove is running. The only difference is instead of it being nice balmy 70° air, it's 30 or 10 or worse. And now that you're bringing the outside temps in (something you're trying to fight off burning your stove in the first place), go turn your stove up higher and burn even more pellets.

Do you need an OAK for your stove to run successfully? Not in 99.99999% of the cases. Will it heat your space more efficiently WITH an OAK? Hmmmmm...

Of course, run your stove how you'd like. You're still saving a ton of $$$$ over oil or gas, but you're also decreasing the effectiveness and efficiency of your stove, and creating all sorts of drafts in the process. Like what's been written a hundred times before, the combustion air HAS to come from somewhere, and unless you have oxygen tanks hooked up to your stove, it's coming from OUTSIDE. PERIOD.

Does anyone really need top men doing scientific research to verify this concept?

again

Madcodger said:

OK, I can't resist... Seriously? You want a study?? You have a combustion device... That requires air. That air is being actively pumped into the combustion chamber and almost immediately after the reaction we call fire occurs, it is actively pumped outside. PUMPED outside, because that's what a combustion blower does! Air comes in, combustion occurs, air goes out.

What temperature is that air going into the combustion chamber UNLESS it is being pulled in DIRECTLY from outside? How about ROOM temperature? And how did it become room temperature? Is there a magic supply of room temperature air reserved just for the stove? No, YOU HEATED IT to room temperature! And by actively pumping that air into the stove and back out, what you are doing is increasing the RATE of air changes that occur. For just this chain of events, It frankly doesn't matter whether your house is "tight" or drafty if a sufficient volume of cold air can be obtained (and if the stove burns, there is sufficient volume). Either way, you are accelerating the RATE at which you bring in cold air, heat it, and pump it back out.

Honestly, I am just at my wits end with people who can't grasp this. There is just no way to help you...

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I understand your position completely however is it your contention that with an OAK installed vs the same situation with no OAK that a substantial volume of already heated air is conserved to the point that the continual loss of air/heat through convection is marginalized so much that the OAK is compensating enough so that the normal heat/air loss is is surpassed and makes the modification justifiable or is it insignificant unless you have a really tight home? That is where I am going with this.

Good stuff guys,would have an oak if pratical.More insight,doctors discovering more health problems in tightly sealed houses,no air exchange.European stoves sometimes do not have sealed oak connection to let house breath.Just more info.

I will also agree with Defiant, to an extent, that an OAK can introduce humidity to the inside of the stove. But in the case of a stove in operation, it's irrelevant. When it absolutely poses an issue is in the off season, as it facilitates a nice convection loop to set up shop and accelerate the formation of rust. In that case, the solution is to plug the the termination and OAK intake. Damp Rid in the firebox works well too. DON'T forget to put everything back in "burn mode" come heating season! At the end of the burn season, I unplug the stove and put a nice big piece of painters tape on the plug as a reminder.

P38X2 said:

Well stated.

It's not just you.

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Agreed

BrotherBart said:

Not any one that I have ever seen.

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I am assuming a below ground basement... bad assumption on my part.

bob bare said:

Good stuff guys,would have an oak if pratical.More insight,doctors discovering more health problems in tightly sealed houses,no air exchange.European stoves sometimes do not have sealed oak connection to let house breath.Just more info.

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Well maybe if you have a ziplock bag over your house. You're still gonna have leaks. That, in combination with everyday exterior door use, will probably create enough of an air exchange to keep things healthy. I'd think you'd really have to do an INSANE amount of air sealing to cause serious health issues.

P38X2 said:

Well maybe if you have a ziplock bag over your house. You're still gonna have leaks. That, in combination with everyday exterior door use, will probably create enough of an air exchange to keep things healthy. I'd think you'd really have to do an INSANE amount of air sealing to cause serious health issues.

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That is my point,what you are thinking is what people thought for years,and are finding out different.I lived in a 1/2 house,upstairs,super sealed,radiant ceiling heat back in the mid 80's.In winter,had to air out house(open all doors and windows)once a week.If I farted,same thing,would not go away.I'll take my drafty old log cabin any day.

I bought my pellet stove and then i read here i should install an OAK. at first i didnt think it was necessary, but after reading how everyone swears by it, i went out and got an OAK. Shes a real beauty. Planted it right in the backyard. It's about 20 feet tall. I'm not sorry i got this OAK but i must say i really dont notice a difference in the house?
The house however is a bit cooler in the summer due to the shade. Is there a specific spot this oak should be planted to make a difference?

bob bare said:

That is my point,what you are thinking is what people thought for years,and are finding out different.I lived in a 1/2 house,upstairs,super sealed,radiant ceiling heat back in the mid 80's.In winter,had to air out house(open all doors and windows)once a week.If I farted,same thing,would not go away.I'll take my drafty old log cabin any day.

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Ok, point taken. However, a non-OAK setup is not a good way to facilitate air exchange. WAY too much volume and way too inefficient. Not really sure how they work, or what they're called, but there are units that can be installed to efficiently get the job done. Air exchangers, maybe? Idk.

BrotherBart said:

I have a suggested place.

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Ouch! heh saw it comin

Greenhorne said:

I really can't see any benefit unless your home is so tight that when your wife farts at night while sleeping... the sudden increase in pressure airlocks the house and now you cant open the door in the morning without cracking a window first....

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Tears of laughter!

I'd rather push warm air out through the leaks in my house rather than draw cold air in through them. My OAK was less than $25.

I agree with the obvious conclusion that an OAK must be more cost effective. The question is, how much? Is it 2% or 20%?. I suspect there are so many variables that it would be almost impossible to calculate without constant monitoring of a dozen factors. At a burn rate of 150 bags of pellets a year is it a 3 bag savings or a 30 bag? I haven't seen any hard data at this point. If it is a difference of 10 more bags a year, is it worth the expense and extra plumbing to clean and maintain? My OAK install is not a simple affair and requires big expense and a visual impact bordering on industrial. The fart test, though interesting, is hard attach a bag count to. Greenhorne is saying the same thing and yes I do want to see a study before I commit my hard earned dollars.

^it's not only cost, but comfort too.
we sit on the carpet in the stove room when we hang out there. backgammon etc...
without the oak there was a very uncomfortable cold flow of air along the floor moving toward the stove.
now there's not.
even with the floor fan on low blowing in, it's not cold like it was pre-oak.

our house is in no danger of being "too tight".
positive pressure ftw!

OK, FOR THOSE WHO WANT PROOF OR COST OF NO OAK - CALCULATE IT FOR YOURSELF

Alright, let's solve this once and for all... It will probably decrease Webbie's server load enough to make this worthwhile, so here goes...

First, for those of you who think this is about whether your stove, "works just fine" without an OAK, that is not our argument or point. We understand that you have enough air to allow for combustion and that you are staying nice and toasty. We are not arguing that. We are arguing that you are using more pellets than necessary to stay nice and toasty. So to help out those new to pellet heating, and save some of us from the rest of you driving up the cost of pellets because you throw supply and demand out of balance (I am about half joking there, but only half), here is your ability to calculate this, for yourself, as long as the very nice people at Lincoln Electric keep their online heat loss calculator up and running. I don't have any relationship to that company, but understand that they make welding equipment, industrial automation products, and other such things. Go buy something from them or tell someone that welds or automates factories how helpful they are, and get them to buy something, and you can calculate guilt free... But before you get started, some information you will need:

CFM (cubic feet per minute) of your pellet stove blower. If you don't know, many are about 80. And if you think yours is more efficient, use half of that, or 40 CFM. This is the amount of air your stove is pulling in from outside, using for combustion, and then pumping back out. If you have a pellet stove and no OAK, you are accelerating the rate at which your house exchanges air by this amount. When your pellet stove is not running (or if you have an OAK), then your house is exchanging air at a rate that is this much less per minute. This is a very important point, and is the basis of the whole reason behind an OAK.

Hours Worked Per Week (this is the number of hours your stove operates per week)

Available BTU per Unit. Most agree that pellets have about 8,000 BTU per pound. Yes, there are some that are more than that, maybe 8200 - 8400. But once you figure in a bit higher moisture content from sitting around the box store lot or your house, you are probably a bit lower than 8,000. So use what you want, but 8,000 is fairly generous.

Cost of Fuel per Unit. How much do you pay for a pound of pellets? At $250/ton, that's $0.125. At $229, $0.1145. At $200, $0.10 (and I'm skeptical that you're getting 8,000 BTUs from that pellet, but whatever... Keep on rolling along here)

Degree Days per Year. I do not have time to go into degree days in depth here, but think of it as the average difference between the temperature of the air outside and the temperature you want your house to be, multiplied by the length in days of your heating season. (For those of you into weather calculations stop twitching at that oversimplification and let's move on - we're just trying to help people calculate something here, not pass a meteorology exam). YOU DO NOT NEED TO CALCULATE THIS - IT IS AVAILABLE IN TABLES ON THE SITE THAT HAS THE CALCULATOR. Where it asks for "Air Temp", that's the temperature you want your house to be.

Now, here is the link to that calculator: http://content.lincolnelectric.com/products/automation/heat-loss.asp

I figured out that one of my stoves would cost me about $80 - $130 per year, depending on how long I ran it, without an OAK. Multiply that by several years, and it adds up. I bet if you were taxed by that amount you'd go crazy, and that's essentially what you're doing without an OAK - taxing yourself by buying an excessive amount of pellets.

So there, knock yourself out. Calculate for yourself. And thank the people at Lincoln Electric. I think I may go take up welding or something...

Defiant said:

My indoor humidity runs a consistent 30+%, you should be familiar with CT weather, last week during all that rain outside relative humidity was 98+%.

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That is relative humidity. It doesn't mean the same thing unless it is at the same temperature. Unless you have a dehumidifier running in your home during winter, I guarantee that the air in your home contains more water than the air outside.

Harvey, I run a humidifier near the pellet stove and a large cast iron kettle on the wood stove to keep the moisture levels at 30%.

I ran the numbers and for my situation it looks like $150 to $200 per heating season. That is about 25% savings for an OAK instalation.. Does that assume no air infiltration in the heated space? It seems the numbers are to good to be true. Any engineering types out there to give an opinion on the calculation? If the numbers are good, it is definitely worth the effort.

Defiant said:

Harvey, I run a humidifier near the pellet stove and a large cast iron kettle on the wood stove to keep the moisture levels at 30%.

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I said dehumidifier.

I don't mean to be rude, but do you understand the concept of relative humidity?

Harvey Schneider said:

I said dehumidifier.

I don't mean to be rude, but do you understand the concept of relative humidity?

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I guess not, I have a digital instrument that measures outside and a few other manual ones that measure inside.