condar vents

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Jan 27, 2010
51
Bowling Green, Ohio
Does anyone use one?
In my other post, I've hinted at having negative pressure (even though there is nothing running @ the time) (I get drafts through doors, windows, return vents, etc.
I spoke with a guy @ Hearthstone who referenced the dryer vent style thing to help equal the pressure.
Why in the world would you have a 8" hole in the wall to just let constant cold air in your house? I see this working well in Florida/North Carolina but not when outside temps are 15 degrees.
Maybe I need a physics lesson but if I wanted to heat the outside I would just live in a freaking igloo.
 
I tried one years ago and installed it about 2' away from my stove. Doesn't do anything different than leaving a window cracked. Someone once gave a tip for basement negative pressure problems to run a dryer vent from the sill plate down into a 5 gal bucket and that would keep the cold air at bay in the bucket til the house pressure needs it and it will flow out. Never tried that but he swore it worked.
 
Wouldn't an outside air kit solve the negative pressure issue? That way the stove would be getting the air and not your house.
 
Hearthstones are great to hook up to outside air. You need to actually hook them up to outside air to get the full benefit. Now I will admit that the device from condar will supply air to a stove that is starved of air and can solve many of the issues that an OAK can solve. What you won't get are the benefits of a connected source of outside air such as humidity retention and max efficiency.

You may as well open a window, perhaps it is a safety issue with people wanting to lock their windows shut.
 
my current fireplace has a make-up air pipe that we capped off when we installed the insert.
The ash box was also sealed up with foam/spray foam and insulation.
The stove has been leaking cold air (combination from down chimney and I believe a bad install)
What I don't understand is that if we opened the oak pipe up -what keeps this air from coming into the room?
I understand the whole pressure argument and I'm starting to wonder that if I opened crawl vents (really packed em shut this year with styrofoam) if this would help? I don't remember as many drafts last year (maybe I'm getting old?
or we need more soffit vents in the attic to get the air out ? (plenty of roof vents)
Bottom line is that I've read the "shut off your fans" all day long but no one really has a solution. We get air coming in all the time (furnace "all electric hvac" can be off . This is what makes the Internet such a great place to learn whats happening.
 
Highbeam said:
Hearthstones are great to hook up to outside air. You need to actually hook them up to outside air to get the full benefit. Now I will admit that the device from condar will supply air to a stove that is starved of air and can solve many of the issues that an OAK can solve. What you won't get are the benefits of a connected source of outside air such as humidity retention and max efficiency.

You may as well open a window, perhaps it is a safety issue with people wanting to lock their windows shut.

Don't mean to hijack this thread (too much)...
Highbeam, is your house really tight? and is that why you installed the OAK? I was checking out your install thread and was wondering if I might get better performance from my Hearthstone (non-soapstone). Currently my house is pretty leaky, but we just insulated the walls and added insulation to the attic/eaves. I am replacing windows a few at a time (as budget permits), so theoretically things should be getting tighter... Draft on the stove has been okay (no back puffing... just have to be careful when opening door to reload), but i attribute that to a 6" pipe going to an 8" SS liner.
 
FWIW, I own a Condar, have a tight house and I work as a residential energy advisor (Canada) so I see a lot of houses with combustion issues resulting from the homeowner not having adequate air supply to the stove, furnace, etc. It's usually issues like smoke spillage, poor start-up, and general "under-performing."

I love my Condar and it has addressed the de-pressurizing effect on my home as measured with my blower door. An OAK would have accomplished the same effect but I also use a Humidex and I wanted a supply of fresh air entering the house to off-set the humidex. My Condar is located 6 feet above the back of my stove. I also leave it wide open all year long and from my anecdotal view it does not cause ANY significant heat loss in the home -- at least no more than a HRV would and perhaps quite less, if I had one.

Having done over 600 home evaluations I can say that most homes need a better supply of air for their stoves. My personal opinion would be to address it in a more robust manner than cracking a window. OAK's are great, Condar "$100 hole in the wall" works great, too. If your stove is designed for an OAK I'd recommend having a hard look at that option since it will directly affect the condition you are trying to fix.
 
here again I need a physics lesson...Do these vents have a flap so that they eventually equalize?
I understand the concept. just trying to understand why I want a to have a open hole in the wall when I can just crack the sliding door....Now if these things have a flap that only opens as pressure variances-then it would all make sense but that's not how they look......Please make me see this crystal clear lol.
 
Sounds like you understand it perfectly -- a cracked window achieves the same effect. The Condar is simply a hole in the wall and you slide a lever to adjust how much air you want to come in. No rocket science tough -- just a 4 inch hole to the outside. The front cover diffuses the air coming in so you don't even notice it -- the air basically fans out up and down (I should note it is a very small amount of air that comes in). The reason there is no baffle or swinging door is because if the house is not depressurizing then no air will be drawn in anyway (no vacuum effect).

The important point is that it is a neat product, nothing fancy, does what it is supposed to and there are a million other ways to achieve the same effect. From my position I would simply suggest we eliminate the negative pressure (or reduce) and allow sufficient combustion air for our appliances. I went this way but I don't want to suggest an OAK is not equal, better, or worse. I also like the fresh air it brings in and how the air doesn't feel like a "window is cracked somewhere" -- this condar really does a good job diffusing the air.

Cheers,
 
thanks for the reply!
I'm grabbing the whole concept....just dealing with a major case of neg. pressure in the house (ranch/with crawl.
Getting a lot of cold air down chase (yes its on the outside) I'm going to have them or someone else install a blocking plate and wrap the liner. As I noted before/another post my old fireplace used a make up air tube but I have no idea where or how this came into play. It was plugged up upon this install. (4" pvc through chase above ash cleanout door)
I just dont know to reopen this tube or go with a Condar that I can crack open a bit? (once I get my pressure problem dealt with)
I am working on foil taping the hell out of all my ducts in the crawl to balance the pressure. I also cracked one of my under house vents to see if this would help any.

One other soapbox for the day...I think one reason that our economy is in the crapper is that some people just don't take any pride in their work...they just want to pass the buck...do a half ass install and tell you to live with it.
I'm only 31 and I've learned in the last few years that maybe every project of mine should be DIY because it might take longer but I'm growing confident it might be right.......
This goes from our furnace installers telling me that supply ducts should just be "hanging " below the duct loosely spewing air out into the crawl (really! and no they aren't some fly by night lol). to the fireplace installer that is telling me having a room be 50 degrees with an insert is normal and live with it. If we all just started taking some pride in what we all do....we could turn this country around. Maybe we could start a thread about funny stories/frustrations we have had?
 
There's certainly a lot to be said for expert advice! You've done a lot of work on the home -- more than most homeowners would take on.

Keep researching the OAK/Condar/ punch a hole in your wall options and you'll definetely come up with the right solution. I like my condar and like I said before -- an OAK would be great too. I would add that most houses are negatively pressurized based on my experience and the condar would fix that. However, an OAK will address your combustion spillage issue (if you ever have one). Certainly don't be afraid to install an OAK as you'll get a mixed bag of responses from this group on it. Worst case, you try the OAK and you don't like it you're not out much money. With the Condar you are definetely out around $70-100 but you can close the lever and pretend it never existed.

Good luck!
 
I guess my main ??? is that if I unplug that tube..will it work? or does the ash door need to be open? Eitherway....I think I like to be able to be able to control the Condar vent and not have to go outside to plug/unplug the vent. We get a lot of wind from West (house sits west/east with chimney on the west...so main concern would be that even colder air would just continue to penetrate the box. I've got plastic all over the stove and the room is still cold...I'm hoping that a block off plate and a blanket will tame this issue a bit (room was never that cold with damper and doors shut on the fireplace) My main concern is trying to get a seal from the firebox...but I didnt know if I could put rockwool and crap around the pipe (my suspicion says yes (thats whats in gas stoves you silly goose lol)
 
[quote author="VTHC" date="1264790667Don't mean to hijack this thread (too much)...
Highbeam, is your house really tight? and is that why you installed the OAK? I was checking out your install thread and was wondering if I might get better performance from my Hearthstone (non-soapstone). Currently my house is pretty leaky, but we just insulated the walls and added insulation to the attic/eaves. I am replacing windows a few at a time (as budget permits), so theoretically things should be getting tighter... Draft on the stove has been okay (no back puffing... just have to be careful when opening door to reload), but i attribute that to a 6" pipe going to an 8" SS liner.[/quote]

My house was built in 1963 and is not tight. I have tightened it considerably with new windows, doors, and a a case of caulking but it will never be tight. I installed the OAK because it made good sense to me and it is required by law in my state. My previous insert/masonry chimney had no OAK and I could feel the cold air rushing into the stove. Humidity was very low. With the new stove I don't get those drafts and the humidity is easier to control. I believe in heating the room air once vs. constantly heating fresh air sucked in by the vacuum created by a non-OAK stove. I also believe that a stream of cool, dense, oxygen rich air is good for combustion. In my remodels I have added two macho bathroom fans and one macho range hood fan that in theory would cause a negative pressure situation but I know that it isn't an issue with my OAK equipped stove.

I would install an OAK even if I lived in a super leaky cabin. It makes too much sense.
 
I was thinking the same thing Highbeam... Seems more efficient to heat air once and use more dense cool air for combustion (much like a turbo charger on a car). Maybe i'll install one this summer for next season (along with blower/rear heat sheild) if budget allows. For now, my Shelburne is running pretty well.
 
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