erv condo, odor transfer to the corridors

[Canadaq]

Hi,

I live in a new condo building in Toronto which uses the ERV system with individual fresh and exhaust vents for each unit and separate ones for the corridor and the front doors are weatherstripped to lower air transfer between the units and the corridors. There was never any cooking odors in the corridors until suddenly since about two months ago at about the same time a few nights a week there is strong cooking odors in the corridors, so strong that it seeps into my condo from around the front door and if you open the door it is quite warm and smelly, like you opened the door into somebody's kitchen. New neighbors have also moved into a unit on our floor at that time. I know that they don't keep their front door open when cooking, so what could be causing this?
Thanks

[stvc]

Can the tenants shut their Erv's off?

Just a guess but thinking the new tenants might not have realized what it was and shut it off.

[Canadaq]

Yes! I think people might confuse it with the bathroom fan and just turn it on when using the bathroom. Would the ERV being off cause this much air to come into the corridor though?

[tinknocker service tech]

it is also possible the evr in the hallway needs to be serviced
or isnt working

[Canadaq]

They say they checked the corridor erv and it works fine. Does cold weather affect how well these things work? Also, can they increase the pressure in the corridors so it wouldn't allow the air from the condos to come into the corridor?

[stvc]

Yes! I think people might confuse it with the bathroom fan and just turn it on when using the bathroom. Would the ERV being off cause this much air to come into the corridor though?

I would suggest a letter to everyone from the condo ass. reminding everyone on the proper use and advantages of the ERV's first.

As far as it being off causing air to move into the hallway is hard to say without being there. It is possible with it off for there to be pressure difference, it is also possible they have a window open.

To your question on increasing hallway pressure I wouldn't, that would also force that air into your apartment.

Try a little experiment. With your door slightly cracked open do you feel air moving either way? Try a little smoke from something to see.
Try it with your ERV on and off.

[Canadaq]

Hi,
I did the experiment. Air flow is from the corridor to my apartment both with erv on and off. It's stronger at floor level, but even up at the top of the door there is a slight flow inward. Comparatively when I open the balcony door the flow is from outside in up to 4 feet and inside to outside above that. I had to actually really seal around my front door for this cooking odor to not come inside.

so with this info, does it mean they would have to have their window open for the odor to come inside the corridor? Could there be some problem with that unit's insulation/weatherproofing?

Also, when you have the erv on, other than the vacuum produced by the bathroom fan, does it actively suck in air from the outside? because the vents are near the top of the ceiling, so based on the balcony door experiment, air wouldn't naturally flow in from that height right?

Thanks

[stvc]

Hi,
I did the experiment. Air flow is from the corridor to my apartment both with erv on and off. It's stronger at floor level, but even up at the top of the door there is a slight flow inward. Comparatively when I open the balcony door the flow is from outside in up to 4 feet and inside to outside above that. I had to actually really seal around my front door for this cooking odor to not come inside.
What I gather from this is your unit is under negative pressure with respect to the hallway [WRT] Try the same experiment at your balcony door to determine your unit pressure WRT outside.
so with this info, does it mean they would have to have their window open for the odor to come inside the corridor?
No, I only used that as an example of something else that could change the pressure in the building
Could there be some problem with that unit's insulation/weatherproofing?
Yes, but there may also be something elsewhere. Multi family buildings can be a challenge for many reasons. Amongst them users with different habits and knowledge, and of course the building itself. I'll try to keep this simple but it won't end up that way. The outside walls are the pressure and thermal boundary, all the walls inside are just rooms in the building. Think single family house, your bedroom is your unit, your brothers bedroom is his unit. It's hard to separate them.
Also, when you have the erv on, other than the vacuum produced by the bathroom fan, does it actively suck in air from the outside? because the vents are near the top of the ceiling, so based on the balcony door experiment, air wouldn't naturally flow in from that height right?
Yes, The concept of the ERV is that it takes air from the outside and tempers it with the air being exhausted thus recovering the energy and providing fresh air. There are a couple other very knowledgeable folks on this site with expertise in this area, surprised they haven't chimed in. Will see if I can get their attention.

Thanks

Hope this helps, BTW, how many floors, units, and what floor are you on?

[Shophound]

Bottom line is that the condo where the cooking odors originate is positively pressurized to the corridor, and the corridor in some aspect is positive to your condo. You stated that improvising some form of seal around the entry door checks the odors. This would indicate the door is the point of entry into your condo, not some other path such as cavities or voids in walls or ceilings.

Are there exhaust hoods over the cooking appliances in the condos?

ERVs can be adjusted for keeping a structure pressurized. But it could be something as simple as encouraging the owners of the the unit where the cooking odors originate to have their entry door seals checked.

[Canadaq]

Thank you all.

yes, there are exhaust hoods over the stoves. They assured me all the exhaust goes out of the balcony, although, sometimes it feels like theirs opens to the hallway. (they are on the other side of the building so their exhaust vent is nowhere near my input vent which is on my balcony as well.)

The entry door seals on these units aren't very good. I had to add several more layers, at the bottom there was almost a pinky finger thick gap. still there is a small breeze at the bottom.

if the erv is on even minimum, the bathroom fan turns on as well. There doesn't seem to be a way to have it on and not have the fan on at the same time. I never put it on high because you get the nextdoor neighbor's exhaust pulled in but it's still much better than the corridor odor!

yes, when I open the balcony door the airflow at the front door goes the other way. But in winter we would freeze to death also within minutes but I'll try it with the smaller window and see what happens.

Yes, there are people right bellow me. Should I try to decrease this internal stack by lowering the temperature? is it contributing to the problem? I tried at 75 degrees and the flow from the corridor to my home is
slightly less.

[thermojohn]

yes, there are exhaust hoods over the stoves. They assured me all the exhaust goes out of the balcony, although, sometimes it feels like theirs opens to the hallway. (they are on the other side of the building so their exhaust vent is nowhere near my input vent which is on my balcony as well.)

The entry door seals on these units aren't very good. I had to add several more layers, at the bottom there was almost a pinky finger thick gap. still there is a small breeze at the bottom.

if the erv is on even minimum, the bathroom fan turns on as well. There doesn't seem to be a way to have it on and not have the fan on at the same time. I never put it on high because you get the nextdoor neighbor's exhaust pulled in but it's still much better than the corridor odor!

yes, when I open the balcony door the airflow at the front door goes the other way. But in winter we would freeze to death also within minutes but I'll try it with the smaller window and see what happens.

Should I try to decrease this internal stack by lowering the temperature? is it contributing to the problem? I tried at 75 degrees and the flow from the corridor to my home is
slightly less.

Everything in bold indicates to me your unit has the ability to achieve a negative state created by a combination of mechanical operating exhaust devices. ERV, bathroom fan, kitchen exhaust, and I suspect your air handling unit are all factors.

I tried at 75 degrees and the flow from the corridor to my home is
slightly less.

So when you turn the unit down from 80° to 75°, you notice the air from outside to in less, meaning less negative pressure when the heating system turns off?

How many square feet is the heated space?

You indicated earlier that it is cold at your feet and warm up high. Are your return (intake for unit) grille, and supply grilles all in the ceiling?

My real gut feeling of your problem, though, points to the prevailing wind as the culprit, IMHO. I'm getting the impression that the wind is blowing through your neighbors unit, carrying the aroma through the corridor, and continuing right through your unit, and out through the rear on the balcony. This is not related to stack effect, but another force that affects the conditions of the living space in a major way.

I would recommend sealing around exterior cracks and crevices around your unit as best as you can to stop the 'flood' of air. Anything beyond that will require a professional with qualifications in building envelope analysis. House maintenance most likely would be in the dark for a real solution. It would be interesting to see the results, as there is a lot going on here.

[Canadaq]

Thank you.

the wind theory seems interesting (not very good for me though! ). I should follow wind patterns and how bad the smell gets.

also I thought maybe the exhaust ducts in the corridor have a leak.

yes, everything is in the ceiling and it's a small apartment. seven hundred or so. At 75 degrees there isn't much temp difference, but at 80 degrees it's too cold at the floor and a sauna at head level.

I'll do some more experimentation later.

the management was very accommodating and said they are checking things out. I hope it's something simple that can be resolved without bothering the neighbors. meanwhile, off to get more weatherstripping! the choices seem to be either so thick I have to wrestle with the door to get it closed, or so thin there still is a draft

[stvc]

At 75 degrees there isn't much temp difference, but at 80 degrees it's too cold at the floor and a sauna at head level.

A small difference is to be expected but this sounds extreme. Could you measure actual temp at floor, ceiling and hallway with a reasonably accurate handheld thermometer? Try it with hvac on and off and perhaps different locations in your unit. Something seems odd to me about this extreme difference.

[Shophound]

Hmm...just occurred to me that if the OP's condo has an ERV, and it is exhausting more air than it takes in from outdoors, AND the hallway is positive to the condo (and that hallway is cold or only marginally heated), this might 'splain a few things.

[thermojohn]

Hmm...just occurred to me that if the OP's condo has an ERV, and it is exhausting more air than it takes in from outdoors, AND the hallway is positive to the condo (and that hallway is cold or only marginally heated), this might 'splain a few things.

My thoughts, too. The imbalance created by all the exhaust equipment, including erv, is quite a strain on a 700 square foot space.

Include a steady prevailing wind around poorly installed or worn out weatherstripping, and the wind pushes and sucks the air out of the space. As many exhaust penetrations there are in the living space, I'm wondering if the forces of wind create a venturi effect, allowing uncontrolled infiltration/exfiltration as well.

Finally with the return and supply at the ceiling of the conditioned space, there would be obvious temperature difference in just 8 feet of column if the wind is moving through the space.

[Canadaq]

Hi all,

No, no more info. waiting to hear from management. Do you guys have any band aid recommendations? extra weatherstripping somewhat improved the situation, but I still get some smells coming from the fresh air vent (although it's hard to say, it is pretty close to the front door). Whoever thought of putting fresh and exhaust vents both in the balconies of tiny apartments was a real genius.

btw, if the fans are off, does wind blow in air through the exhaust vents?

[Shophound]

Hi all,

No, no more info. waiting to hear from management. Do you guys have any band aid recommendations? extra weatherstripping somewhat improved the situation, but I still get some smells coming from the fresh air vent (although it's hard to say, it is pretty close to the front door). Whoever thought of putting fresh and exhaust vents both in the balconies of tiny apartments was a real genius.

btw, if the fans are off, does wind blow in air through the exhaust vents?

Exhaust fans should have dampers to prevent intrusion of air when the fan is not running.

Is it possible air being exhausted from a balcony near yours contains cooking odors that are being ingested by your ERV?

[Canadaq]

also, approximately how long does it take for the air to completely exchange with all the ventilation off and the balcony door open, assuming no wind and just the stack related air exchange from the balcony door?

[Canadaq]

yes, that is also a problem, but not as bad as the corridor.

do fresh air vents have dampers too? (I mean do you get fresh air blown in with the erv off if it's windy?)

[thermojohn]

Dampers.... They work when they work. Most spring loaded butterfly dampers are great when they are new. Add real world stuff like several years of exhaust 'crud', and they stick open, or closed. My experience is that they should be inspected periodically to ensure they are indeed functioning as designed.

Gravity operated 'flappers' have to be positioned properly, or they don't work at all. Again, house maintenance personnel usually don't really care or know - you have to be your own advocate, and informed when you are a tenant. I hope we're providing some direction here for you.

Where are they? Anywhere in line with the exhaust duct. That needs to be established, and notated for future reference.