Do I Want to Suck Air From Outside or Increase Air Flow?

I just went to the store and bought everything to do both.

What is better, getting my intake air from outside OR increasing my air flow thru my intake. I have seen people on here do one or the other.

My stoker is in my basement and sucks air from the floor of the basement... heated air. Sucking it from outside would not take my heated air out of here.

My stove is the triburner design that I run all the time on full blast. I adjust the lobe for heat needs. Many have added an external fan (50 cfm) to add to the air going into the stoker for a more complete burn.

I just went to the store and bought the goods to do both. What one would be more efficient? I am guessing the added intake blower fan.

Help!

Outside makeup air is a good thing because people are making the houses tighter.

Just wanted to make sure you are talking about the Combustion Air for burning (not the Baro damper air?).

Using outside combustion air may help some, but running the combustion blower at full without any rheostat helps the burn also.

arcticcatmatt wrote:My stoker is in my basement and sucks air from the floor of the basement... heated air. Sucking it from outside would not take my heated air out of here.

I actually like having my hand fired stove take colder air off the floor of my finished basement & have enough air infiltration through window frames down there that there is plenty of combustion air to burn. I guess the ideal situation would be to have a dedicated combustion air line to your appliance though, if your decor (wife) will allow it.

No wife here. Just long term live in girlfriend.. soon to be wife I bet. She dont' care how I do it, she just likes it warm in here for cheap. She laughs at the stuff I do until she see's it work, then its "wow" nice work honey.

WNY wrote:Just wanted to make sure you are talking about the Combustion Air for burning (not the Baro damper air?).

Using outside combustion air may help some, but running the combustion blower at full without any rheostat helps the burn also.

Combustion.

I bought all the goods to either suck air from outside OR increase the air flow coming in (bought an external fan that others have used on here from home depot to increase the air flow thru the stoker grate, combustion air)

Thanks for the replies. So far suck air from outside is winning since I am already running my intake fan on full blast at all times.

arcticcatmatt wrote:I am already running my intake fan on full blast at all times.

In a tight house that fan will be gasping for air, an outside air supply source will give you quite a boost.

Is cold air harder to heat than warm air? I am wondering if sucking COLD air from outside will make my stove run colder since its taking more energy to heat COLD air vs. warm air.

arcticcatmatt wrote:Is cold air harder to heat than warm air? I am wondering if sucking COLD air from outside will make my stove run colder since its taking more energy to heat COLD air vs. warm air.

With the high temps needed to burn coal in your stove, cold combustion air (within the stove) will make no difference at all to your stove's heat output.

I have my stove plumbed with outside combustion air because I was always concerned that with a tighter house the combustion fan may be competing with the baro for the air. And if the combustion fan wins the fight it may draw flue gas out of the baro.

^ True! I am going to start plumbing in my new cold air intake in the morning! Hopefully it will make it more efficient.

Think of your house as a box. You got a 6" chimney coming out of the box that is constantly taking air from inside the box and spitting it outside. Your box doesn't like a vacuum or it would collapse so it sucks air in around cracks, windows, doors through exhaust fans, your clothes dryer, etc. That's cold outside air that you now have to heat to be comfortable. If you take outside air directly to the combustion intake, you can eliminate alot of this air infiltration. Large commercial buildings actually pump air in to keep the building under positive pressure. Your house is usually under negative pressure.

^ Very true.

Anyone done a study on their house with this theory with sucking in outside air?

I just hooked up a few of my pieces even though it is 10 PM. The hole (I didn't know) in my intake is 2.5 inches. Of course, nothing is that size so I have a 4 inch 90 degree adapter that is for clothes dryers pressed against it. I will use ductape as this area is cold. I have about 40 feet to run. I will post pictures tomorrow if anyone is interested.

Maybe I don't understand your post. Why not pipe outside air to an additional combustion fan and kill two birds, one stone Scott

I agree with the thought of using the outside air for your combustion air for some of the reasons already stated. One thing to keep in mind is that your fire really doesn't care about the temp of the air coming in. The fire is looking for the oxygen in the air, not the air itself. When you increase your combustion air, all you are really doing is feeding the fire oxygen at a faster rate. The amount of airflow will also change your draft though. If there was no oxygen in the air you could pump 1000cfm and it wouldn't help your fire burn any better.

gambler wrote:I have my stove plumbed with outside combustion air because I was always concerned that with a tighter house the combustion fan may be competing with the baro for the air. And if the combustion fan wins the fight it may draw flue gas out of the baro.

coalkirk wrote:Think of your house as a box. You got a 6" chimney coming out of the box that is constantly taking air from inside the box and spitting it outside. Your box doesn't like a vacuum or it would collapse so it sucks air in around cracks, windows, doors through exhaust fans, your clothes dryer, etc. That's cold outside air that you now have to heat to be comfortable. If you take outside air directly to the combustion intake, you can eliminate alot of this air infiltration. Large commercial buildings actually pump air in to keep the building under positive pressure. Your house is usually under negative pressure.

These are both very good points IMO.

Jeff

Actually there is this thing called a Carnot heat engine. It plots overall efficiency. There greater the difference in starting temp as compared to ending temp is how they figure efficiency. So that would mean the colder air would be more efficient. Really the 100 degree difference in starting temp is only one twenty seventh of the whole issue, so it doesn't come into play. I think Scott