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Discussion Starter · #1 ·
Hi all, I'm new to the forum and have a question about a strange setup in my newly-purchased home that has me puzzled.

I have a turbine vent on the lower roof of my side split that is piped to the basement. It blows fresh air into the basement. My in-laws, who live across the street, have the same setup. They have referred to it as a "Venmar" but it is like no Venmar system that I am familiar with.

I haven't been able to locate any information about this strange setup online... I'm going to cover it up for the winter as it gets pretty nasty up here in Northern Ontario and I don't like the idea of pumping cold air into my warm house.

Can anyone offer any insight into this? Thanks.
 

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Strange. If you have fuel burning appliances in the basement it could be some sort of system to supply them with combustion air. If they're in a small room, lack of fresh air can be a big problem. Combustion air can be brought in from outdoors, but I never advise it because people do just what you're talking about...Covering it up. I've never seen a turbine vent to provide combustion air.

How big is your basement?

What is the btu/h input rating of the furnace (on the sticker inside the furnace access door)? Is it a high-efficiency unit with PVC pipes for vents? How about the water heater size and btu/h's?

Here, the code for combustion air is at least 50 cubic feet of room for every 1000 btu/h's of appliances. If the furnaces or water heaters are sealed combustion high-efficiency that get their air from outdoors, they don't need interior combustion air.

I'd suggest contacting the builder that built the homes to see if he can shed some light on the system installed in them. You might also post some pictures here!
 

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Venmar is a major manufacturer of HRV or ERVs. Energy recovery ventilators. They are used in your part of the world to supply tempered outdoor air to your home whenever your bathfan, range hood or furnace operates.

Outdoor air and tempered indoor air that is being exhausted, pass accross a heat exchanger that transfers energy from one to the other, saving you money. These are normaly offered during construction as an add or extra.

Due to more energy efficient, tighter construction, the outdoor air is a requirement and keeps you healthy.

If it is just pumping air into the basement, and not an identifiable ERV or HRV, it is probably an attempt to satisfy the minimum code requirement for fresh air. Invest in an ERV or HRV and start saving some money,
 

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Discussion Starter · #4 · (Edited)
Thanks for the replies. I am familiar with heat exchangers. In 1981 (when the house was built) I'm fairly certain that minimum code requirements did not call for any such device. Does anyone know for sure?

The basement is large, with a high efficiency natural gas furnace (1991) and natural gas water heater (newer). It is a full basement (including under the garage, a good topic for another post). The house is about 1500 square feet upstairs so the basement would be similar in size.

The house was originally equipped with a wood/gas furnace (wood was stored under the garage) and a wood fireplace upstairs. Perhaps it provided fresh air for these? The vent comes out in the main recroom and the utility room is right off of that. On a side note, my in-laws with the same device were primarily electric heated, with two wood fireplaces.

Although I am all-for the idea of having a healthy home, I don't want to be flushing out warm air with unheated outside air. If I disconnect the hose at the turbine I suppose I can just use the vent for the attic.

Any other information / ideas?
 

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Just a guess, but is it for radon? Usually the gas is mitigated through an underground fan which sucks the gas (out) from underneath the slab. Or it is vented naturally through a passive pipe system.
 

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Discussion Starter · #7 ·
Just a guess, but is it for radon? Usually the gas is mitigated through an underground fan which sucks the gas (out) from underneath the slab. Or it is vented naturally through a passive pipe system.
Interesting thought, EAP. We do not have radon issues in this area though.
 

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Discussion Starter · #8 ·
It is a Venmar... I was up in the attic tonight inspecting the insulation and I gathered some information from the bottom of the unit. Here's what it says:

Venmar
Patent 1980 - 1095316
Item #60339

I can't find any info on it online. It basically looks like a white bucket with two connectors (one for each hose, to the kitchen and to the basement), and another hole in the side (for the attic maybe?). I may give Venmar a call to see what type of info I can get.
 

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I'm trying to find out about the exact same type of device in my own house. Reilley, did you ever find out anything more about it?

I assumed that it would draw the air out of my basement and hallway, unlike Reilley who claims that it pumps fresh air in from the roof. There are vents inside my house at the end of each of the two hoses, and they've always been closed, so this device has been essentially inactive.

This winter I had a small amount of water leaking through the ceiling at the vent in my upstairs hallway. When I checked in the attic, I found that the hose to that vent had broken away from the pail beneath the vent, and some water had collected in the low spot in the hose. I assume it was from condensation.

Can anyone shed some light on this device?
 

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Discussion Starter · #10 ·
It's been a while since I first posted on this topic. You are right in your theory that it pumps air out of the house as all turbine vents pump air out, at a rate of up over 1000CFM in 15-20MPH winds.

So the issue is that the process in which this air is pumped out creates a vacuum which in turn draws outside air in from leaks around doors, windows, sill plates, etc.

To say that the device could be turned off is not entirely true as vents do not form an air tight seal, especially under the draw produced by the turbine vent.

The idea behind exchanging air in this manner is a great one if you aren't paying to heat the inside air. Up here, in Canada, that only happens for a few months of the year.

I have disconnected the flexible duct work and sealed up the attic bypasses where it once ran. This summer when I have my roof done, I will be replacing the ugly galvanized steel turbine with a typical attic ventilating turbine vent.

Hope this thread was helpful. I was quite puzzled when I first came across this ancient Venmar system.
 

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Thanks for the quick response, it was very helpful. It's amazing how hard it was to find out anything about this setup.
 

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Discussion Starter · #12 ·
Thanks for the quick response, it was very helpful. It's amazing how hard it was to find out anything about this setup.
No kidding! They are in plenty of homes up in this area too... Maybe Venmar realized the error in the their ways and covered up all signs of these units. :laughing:
 

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It basically looks like a white bucket with two connectors (one for each hose, to the kitchen and to the basement), and another hole in the side (for the attic maybe?).
Thank you so much for that info. I have the exact same thing in my 1982 home, and had always thought it was a home-brewed. I now need to deal with it, since the bucket broke and it's lying on the insulation. I fear that attic air can now enter my home through those vents.
 

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Thank you so much for that info. I have the exact same thing in my 1982 home, and had always thought it was a home-brewed. I now need to deal with it, since the bucket broke and it's lying on the insulation. I fear that attic air can now enter my home through those vents.
I'm having the exact same problem : I just bought a 1985 house with this setup. Mine had 3 flexible pipes coming in : one for the basement, the living room and the 2nd floor hallway. And I have the exact same problem : the bucket broke (the plastic it's made of became quite fragile and unflexible) and now it's lying on the insultation. Since we're in june I'm not quite afraid of the consequences for now but I need to fix this before winter. (I live near Ottawa ON so the I only have 3-4 months ahead of me before I start heating the house).

The guy who sold me the house was the 2nd owner and had no idea that Venmar was there. So he won't be of any help.

What did you finally do ? Did you take it all off, replace it by something else or try to restore the same setup ?
 

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(I live near Ottawa ON so the I only have 3-4 months ahead of me before I start heating the house).

The guy who sold me the house was the 2nd owner and had no idea that Venmar was there. So he won't be of any help.

What did you finally do ? Did you take it all off, replace it by something else or try to restore the same setup ?
That's funny, because I'm in Gatineau... Since I posted that (last October), I simply blocked off the vents into the house so that attic air does not come in. But like you, I'll fix it before winter. I'm normally a DIY guy but I think I'll just get some roofing experts in to remove that thing and install proper (modern) vents.
 

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That's funny, because I'm in Gatineau... Since I posted that (last October), I simply blocked off the vents into the house so that attic air does not come in. But like you, I'll fix it before winter. I'm normally a DIY guy but I think I'll just get some roofing experts in to remove that thing and install proper (modern) vents.
In fact, I'm in Gatineau too :) On what street are you ? Maybe our houses were built by the same contractor.

What experts have you found ? None of the ones I brought over had even seen a thing like this old venmar device.

If I get it properly, you're planing on having the old turbine removed and replaced by an ATTIC vent ? Or an air exchanger ? I'm asking because I already have modern attic vents (two of them, the Maximum type). So if I get this thing removed, I'm not quite certain I should replace it with anything...

And there's still this question : what if that thing DOES help ? Obviously it throws out warm air in the winter which isn't great, but it might take out humidity too (which makes the house easier to heat AND more healthy). I'm kindda puzzled because no one can tell me if that thing is of any use and I don't feel like spending money to remove/replace it if it's only to save 20$ a year.
 

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In fact, I'm in Gatineau too :) On what street are you ? Maybe our houses were built by the same contractor.
I'm on Dumais street, in Templeton. Where are you?

What experts have you found ? None of the ones I brought over had even seen a thing like this old venmar device.
I haven't searched yet, but my plan is to have one or two maximums installed. From what I read, the turbine vents are very effective for attic ventilation -- they are simply prone to making noise. It may be easier to simply replace the existing turbine with a new one, properly installed without all the Venmar crud.

When the Venmar was connected and working, I had zero attic ventilation other than from the soffit. Pretty lame.


And there's still this question : what if that thing DOES help ? Obviously it throws out warm air in the winter which isn't great, but it might take out humidity too (which makes the house easier to heat AND more healthy). I'm kindda puzzled because no one can tell me if that thing is of any use and I don't feel like spending money to remove/replace it if it's only to save 20$ a year.
I thought of this, and concluded that for it to effectively remove humidity, it would need to pull basement air from close to the floor (where the humidity is) -- not from the ceiling on every floor. Also, in the winter, most often cold air would flow down through the vent when there is no wind.

Since no one makes a similar product today, I have to conclude that it's not all that effective. Last October, when I had this device completely plugged, I had an expert over to analyze the quality of the air. The lab results showed nothing of interest -- all normal. She did suggest using this device, instead of a dehumidifier:

http://www.ezbreathe.com/

That seems like nothing more than a fan to exhaust basement floor air (humid air) to the outside. Sounds good, but when I asked her where the fresh air would come from, her answer was 'the natural gaps and holes in windows, doors, etc'. I wasn't convinced.
 

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I'm on Dumais street, in Templeton. Where are you?
I'm on Bazin street, in du Barry. Around 10 km west from you. Probably no link in the construction, especially 3 years apart.

I haven't searched yet, but my plan is to have one or two maximums installed. From what I read, the turbine vents are very effective for attic ventilation -- they are simply prone to making noise. It may be easier to simply replace the existing turbine with a new one, properly installed without all the Venmar crud.
If you have no attic vent at all, a maximum is a good idea and it's quite cheap. Good attic ventilation is important. Temperature in the attic should be about the same as outside at all times.

BTW, I just contacted a Venmar representative this morning who knows about this old product. He told me that they stopped making it back in 1995 and discontinued the parts for it in 2008 and that equipment played the role of an air exchanger, before air exchangers were invented.


When the Venmar was connected and working, I had zero attic ventilation other than from the soffit. Pretty lame.
Wasn't there a hole in the Venmar ? Mine had 3 holes for pipes runing to each floor + 1 hole for the attic. Of course, it's not much.


I thought of this, and concluded that for it to effectively remove humidity, it would need to pull basement air from close to the floor (where the humidity is) -- not from the ceiling on every floor. Also, in the winter, most often cold air would flow down through the vent when there is no wind.
Good point about the humidity near the floor... Humm... I'm still puzzled about why the previous owner didn't remove it when he had the roof redone in 2007, even though he had 2 maximums installed.

I'm not sure cold air would flow down through this system : the turbine pumps the air up but if it stops turning it doesn't push any air down. Of course, cold air is heavier but it definitly wouldn't create as much pressure difference. It takes a lot of energy to pull air through a pipe several feet long.


Since no one makes a similar product today, I have to conclude that it's not all that effective.
I discussed that at lenght with the venmar rep this morning and he told me :
1) modern air exchangers are definitly more efficient than this thing (at circulating air), but they cost more, both at purchase and to run. I'm not sure it's worth a replacement.
2) the old device we both have only pumps air OUT and relies on cracks and door openings to get so air IN. Now that used to work pretty fine three decades ago but now that insulation technology and minimal standards for insultation in new houses have changed, it makes this device less efficicent. That's why they stopped making it.
3) Unless the insulation in our houses have been replaced, that device should still work pretty fine.


Last October, when I had this device completely plugged, I had an expert over to analyze the quality of the air. The lab results showed nothing of interest -- all normal. She did suggest using this device, instead of a dehumidifier:
What expert did you call ? I should have a similar test done...

What I'll probably do is to block the turbine for this winter, see how it goes and have the air tested too. Then i'll see if i need to change anything. If there's not enough fresh air getting in, then i'll hesitate about fixing this old venmar vs buying and air exchanger.
 
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