Was lost but now am found -- off to buy an Outside Air Kit

[CO2Neutral]

Well, I was a silent nay-sayer but after watching my stove suffer and then cracking the window and turning off my exhaust devices ( I run a humidex) I now see the benefits of an OAK. My old stove wasn't as powerful and I think my depressurization of the home has reached it's terminal velocity and an OAK is needed now.

Question -- should/can I install this myself? Are they expensive? My dealer is not really *for* them and suggested I not bother. They haven't sold may, either. That being said -- they are a great dealer and I value their opinion but there's a lot to be said for the knowledge on this forum....

Thanks, Mark

 

[Highbeam]

Here's the installation instructions for your outside air setup.

(broken link removed to http://www.chimneysweeponline.com/cpacfusion.htm)

There does not appear to be any sort of extra equipment required to use outside air. Nothing to it, I installed my own for my heritage. Click on the link in my sig for my photos.

 

[CO2Neutral]

Awesome, thanks -- I looked but didn't see that on Tom's site. Much appreciated.

This was during start-up.

 

[LLigetfa]

I 'm an advocate for using outside combustion air but I must say it is not a cure for all the symptoms that a negative pressure situation manifests. The root causes need to be addressed first. The OAK could in fact make some symptoms worse.

A negative pressure situation is caused by an imbalance, often brought on by more air leaving the envelop via stack effect than what is allowed to enter as make-up air. The OAK removes only the stove as a consumer of air. If there are other consumers such as exhaust fans, clothes dryer, water heater, furnace etc., and additional losses to stack effect, the OAK can push smoke into the room when the door is opened.

When I speak of losses to stack effect, it is in regard to warm air rising, pressurizing the upper floors which forces air out through cracks. The warm air loss is not easily noticed as there are no cold drafts felt where the air exits the envelope. Where the cold drafts are noticed is on the lower floors where air infiltration attempts to provide the make-up air. The noobie mistake is to seal up all the cold drafts and overlook where the warm air is lost.

Fix where the warm air is lost, not where the make-up air enters. The less air loss the less cold drafts. The OAK takes care of only one point of room air exiting with a subsequent demand for cold make-up air.

 

[LLigetfa]

...and turning off my exhaust devices ( I run a humidex)...

Please elaborate. Is it like a HVR/ERV whereby it is supposed to exchange equal amounts of indoor and outdoor air? If so, either the entire house is unbalanced as per my former post, or the HRV/ERV unit is itself not properly balanced.

In my home, my HRV is down in the crawlspace and it pushes the fresh air into our upstairs bedroom. Since it has to push colder air up 10 feet, it is naturally unbalanced so I had reduce the volume of air it removes. I also found that the outside intake would clog up with cotton from trees and dandelions reducing the amount of make-up air without reducing the amount of air leaving.

Despite all the fresh air the HRV puts in the bedroom, the wife insists on leaving the window open which creates a negative pressure situation at the stove. I have to close off the OAK and open a window before I can open the stove.

 

[CO2Neutral]

Thanks for the feedback -- I actually own a Minneapolis blower door and have done some test on the house. On a normal day my house is depressurized around -1 to -2.5 PA (I live on the North Shore of PEI_ and the wind effect really packs a punch on my building envelope. On a normal day my house air change per hour at 50 pascals is 2.3 so I'm not overly worried about major leaks (I've used the blower door to find those as well). You definetely nailed it when you said exhaust devices though: my humidex is an exhaust only device that resides in the basement and draws damp air off the floor to the outside. It's CFM rate can be over 100 and with my small home, tight enough construction and a big enough stove asking for air I think I've reached the point at which I'm starving the stove.

That being said -- it's only September and I'll run some more tests to see how I get along.

Will keep you posted.

 

[CO2Neutral]

Wish it was balanced! Nope, straight exhaust device (but I like how it manages my humidity levels). I'm in a 1.5 storey construction so I'll pay attention to the window open/upstairs/stack effect too.

Thanks again.

 

[velvetfoot]

Hi. We just came back from a vacation to Cape Breton and were in PEI a couple of years ago. Beautiful area.
I noticed the same thing in both places around this time, and that was piles of wood on the driveways.
Do the wood guys deliver this time of year? I saw a bunch of that.

I seem to have that downdraft all the time when the stove totally cools off, so I start the fire with the window cracked open a little.
The draft goes the right way as soon as the fire starts. I'll be trying to address possible leaks upstairs, but I bet it can go right past the dampers of the bathroom fans.
Opening the window for a little bit doesn't seem that bad if it works okay otherwise.

No offense, but I can't see the need for that basement exhaust fan. Although, I have also have one in a way: a radon fan that runs constantly and takes suction from under the slab. I haven't noticed any effect when it is turned off.

 

[CO2Neutral]

Yep -- wood delivery is NOW on PEI. Sadly most will be storing that wood in their basement and trying to burn it this winter -- and usually in an old smoke dragon. And they wonder why they go through 6-10 cords of wood and hate it now.

Actually the basement humidex (humidex.ca) is a great unit and very inexpensive to operate compared to a dehumidifier. I was skeptical as well but in my line of work I've seen over 50 installations of them and spoke to (and smelt) some nicely conditioned basements as a result (no musty smell, clean air in the home). I'm fully up-to-speed and endorse a full ventilation system but the humidex does a great job for what it is designed for -- making me install an OAK, just kidding %-P

 

[Highbeam]

"the OAK can push smoke into the room when the door is opened. "

I've heard a lot of strange things about OAK air supplies but I never heard that an OAK could actually pump smoke into the room. Oaks supply fresh air to the fire, are you saying that the OAK will supercharge the stove with more air than the flue can evacuate? That's tough to grasp as any smoke entering the room is due to a lack of flue draft and not a result of sufficient combustion air.

 

[LLigetfa]

Exhausting cold damp air from a basement is a waste of time and energy when the replacement warm and damp air cools causing the RH to spike. Keeping the same air in the basement and running a dehumidifier makes more sense if radon gas is not an issue.

Ja, strong winds can suck air out of the house depending on placement of vents. The anti-OAK crowd like to use that to argue against OAK. If there are frequent prevailing winds that can create low pressure zones one needs to consider them in the placement of the OAK.

 

[bren582]

I read somewhere, can't remember the link, that installing the OAK is best done on the windward side of the house versus leeward if at all possible. Not sure if leeward placement will make matters worse or just render the OAK less effective but the point seemed to be that the windward side would make the OAK more effective and leeward might somehow be unable to draw make up air as well when placed on the leeward side.

To the vets on this forum.. Is there any truth to that ?

 

[CO2Neutral]

Actually, drier air is at the top of a structure and by exhausting out the damp and replacing it with warm, drier air it reduces the relative humidity -- I've been running it for a year like this and I constantly measure the RH and it works. A dehumidifier is expensive at .15 cents/kwh over here. When a dehumidifier costs ~$35/month to run and a humidex is ~$5 it's worth it if the humidity is managed. I will say that a dehumidifier does a better job at getting the humidity down to a lower level since the humidex can only reach the humidity level of the structure upstairs.

 

[LLigetfa]

There is a slight chance the OAK could reverse draft on the leeward side depending on chimney placement. A reverse drafting OAK is a fire hazard.

 

[velvetfoot]

Seeing is believing, and all I know is what I read on the web, lol.

The prefab fireplace (before we put in the insert) originally had outside air. We noticed that the hearth was always quite cold. Not so much now. I guess there are cable operated dampers, and I've read about insulating the outside air duct and making a 'U' trap to prevent the cold air from coming in. Sounds like it might take some fooling around with til you get it just right.

I guess it's more the area of the central heat people, but I've never read about a forced air intake system of some sort for a stove. Imagine if it was supercharged! But seriously, would that be a more definitive way to control combustion?

 

[CO2Neutral]

Stove is absolutely on the leeward side (north winds from the ocean and stove is on the south). And we have wind out here..... oh baby do we have wind. Any thoughts -- go, no go for an OAK?

Thanks

 

[Frostbit]

Why don't ya just install the OAK kit, then add a blend door with a T before it connects to the stove. That way you can select inside or outside air for combustion, and if you're really handy, a combination of both if needed. Then you have all the bases covered.

 

[John_M]

Mark, If the outside air intake on your PE Fusion is similar to my PE Spectrum The OAK installation will be very inexpensive and easy to do. Using information in The Chimney Sweep link provided by highbeam, I drilled a 4" hole in the floor within the footprint where the pedestal will rest. For the install, I had to purchase nothing from Pacific Energy and did purchase two 18" sections of aluminum dryer vent, an upgraded (heavier duty construction) dryer vent hood, and an adjustable elbow from a local hardware store. I already had an open tube of silicone caulk and some 1/4" rodent screen. Total cost about $24 us.

One sugestion: If you choose to drill a 4" hole in the floor, check to see that a floor joist is not in the way and that you will have good access to a vented crawl space or to the outside. Mine is vented to the outside under a deck with any wind exposure perdindicular to the side of the dryer vent hood and mostly from the west. To be certain that the 4" hole in the floor is covered by the pedestal, use some blue painter's masking tape to outline the footprint of the pedestal EXACTLY where the stove will sit. Drill the 4" hole at least a couple of inches ahead of a line directly beneath the Fusion's 6" exhaust. The last thing you want is to have a 4' hole in your floor and 2" of that hole outside the perimeter of the pedestal.

I was nervous about drilling the 4" hole in my oak floor but just "got to it" and am happy with the install. The stove draws very efficiently in all weather and wind conditions and I have noticed no degredation of the inside air. My respiratory system is sensitive to various irritants but have yet to feel any negative reaction to the OAK install.

Good luck, John-M

 

[CO2Neutral]

Thank John -- that makes me feel more confident. I'll give it a go in the next weekend or so. I'll probably go out the back (like highbeam) since I have to route to the outside anyhow (no vented crawl).

- Mark

 

[Wet1]

Pook,
That's an interesting read, but I did not see any references or info to substantiate their claims. Who was this written by, what are their credentials, and where's the supporting evidence to validate their claims? I have never seen or even seen proof of an OAK causing chimney draft reversal. Possible? I suppose, but I've never seen it or heard of it happening other than it being theoretically possible. Given the number of manufactures and codes that require it, I don't think it's all that unsafe.

If the OP is having issues with his combustion and cracking a window solves the problem, I'd support installing an OAK.

 

[LLigetfa]

tend to think that prob only exists at starting fire...

I would have to agree. It does deserve a mention though and the installation of the OAK should take clearance to combustibles into consideration.

 

[CO2Neutral]

Thanks for duking this out fellas -- it appears there is a wide range of consensus on OAK installs. Since my issue was smoke spillage/performance at startup I feel it's best to step back and think about if an OAK will really fix my issue. With an outside chimney, exhaust device in the basement perhaps I just overpowered the startup draft of my cold chimney (external Selkirk)? Would an OAK have prevented that?

 

[Wet1]

Why don't you try a temporary OAK and see how it works out? Go buy some 4" dryer hose and run it from a window to the stove and seal off the window around it. It doesn't have to be anything fancy and it wont cost you much at all. I think you're going to find that it will be beneficial since you have a basement install with an exhaust devise adding to the problem.