EcoVent by Broan?
I have a new home that was built to our local Green Home standards in Northern Canada. I installed 5 of these EcoVents by Broan based on the recommendation of my Green Home Ventilation advisor.
A picture and description is on page 6 here.
At 20$ a pop the vents are the most expensive I could have bought.
What I have now is 3 bathroom fans that will not exhaust (frozen ball), the dryer will only begin to exhaust after the warm air melts the frozen ice holding the ball in the cone (usually 5 to 10 minutes) and I have one vent for an unfinished bath in the basement that is free of ice and works when i tested it the other day (I suspect due to the fact that no moisture is ever present in the bathroom and the fan is never turned on).
Funny thing is, only one of the bathrooms is used for daily showering, the other 2 are used for toilet/sink only. So even with minimal moisture in the rooms and light fan use it is enough to cause freezing at the vent.
Now these were invented in Canada and I have have found some reviews online that state they are the best thing going, but to me they suck. They worked fine in the summer, but not worth a crap in the winter. The home has an HRV and the humidity is about 30 to 35% indoors. All vent ducting is 4 inch dia. with the last 10' wrapped in an insulated sleeve to help avoid condensation in the pipe. All bathfans are Panasonic FV-08VQ3. Runs are straight (no elbows) from fan to wall (about 15 to 20 feet).
If I can't come up with something to fix these things I'll be forced to remove them all next year and replace them with old school metal flappers.
I have tried running a fan overnight hoping that it will thaw the frozen ice, but to no avail. Only the dryer seems to be able to accomplish this due to the heat it puts out.
Sorry for being long winded, hoping someone else has dealt with these fans before.
That's a shame. Looks like a clever design. The bathroom fans should have their own dampers, so the damper at the wall is a backup of sorts. You should be okay with a regular vent. I glued a large washer to the damper to help keep it closed, but it still bangs around some.
There are these for dryers, but they may have the same problem.
I am interested to know if you have had any success. I am in Saskatchewan and it has been brutally cold of late. I vent bathroom and stove out the gable ends and the trad flappers are freezing. I put one of those Eco-Vents on my dryer and it works fabulously well, but the vent is low on a side wall (maybe 2' above grade of the house in a sheltered position). I want to put some on the gable ends but am worried about freezing. Any ideas/solutions.
At what OD temp do they start to freeze shut.
By insulating the last 10', you may have created the problem.
If you still have access to one of the vents. Try removing the insulation and see if that keeps enough heat at the ball to prevent freezing.
beenthere: I can see your theory on this but it is a sort of two way street with the insulated sleeve. Theoreticaolly, it is to keep the transition of hot to cold (thus condensation/ice) as close as possible to the wall/vent. But yes if the vents are only used for an hour a day, the cold creeps into the duct and effectively make it harder to thaw as it is insulated from the house.
On the otherhand, I have two ceiling mounted vents on the top floor that vent through the attic and out the gable ends. The are not insulated by means of a sleeve, but rather they are sitting on top of the bottom truss cord but are covered by cellulose spray insulation. (3.5" thick bottom truss cord, 14" total spray insulation at R3.5 per inch, 4" ducting) So the top of the vent duct is about 7.5" high within 14" of insulation. Covered by about R26, yet the bottom of the duct is insulated from the house by about R12. Also consider some heat is within the insulation. I suspected that the latent heat in the insulatation would effectively act as an insulated sleeve so I did not install them in the attic locations.
I'd be interested in hearing more ideas on this.
The fans are extremely quite except when frozen they make alot of pulsing wind noise due to pressuring the duct to a point then some back pressure, pressuring again etc. I noticed the pulsing in the fall (around October) when the mean temps are about -10C. So I suspect it began around then. Our mean temps now have been in the -30C range for a couple weeks.
toonarmysk: Mine are located in various spots. The one that does work for the unfinished bathroom is under a deck at about the 6' height and probably exposed to the least amount of wind. But I do believe if i was showering in that bathroom the moisture/hot warm air would naturally vent up (ceiling mounted fan) and out the ducting to where it would condense and freeze near the vent anyway. 2 others are located about 15' up on the house facing west, moderate wind exposure (typically a south wind). I have 2 in the gable ends at about 24' facing south. These are servicing baths that are are not used for anything but sink and toilet in one, and our young children bath in the other creating some moisture. Either way both are frozen shut and next to impossible to get to without a large ladder.
Maybe if your fans are oversized (like a dryer) it may thaw the ball on each use and open it within a few minutes, but mine are properly sized for the bathroom requirements.
I think the vents theoretically are a great idea. Obviously I bought 5 of them. But in actual fact depending on the situation (fan size, use of bath, insulated vs. non insulated, mean outdoor temps etc), they may or may not work for you.
Removing them will be somewhat of a chore. I have heard of the white plastic housing coming seperated from the foam (only glued) and one should be able to cut the foam off the duct leaving a short stub of ducting exposed outside the wall. Then one would have to cut this stub back flush with the house and install a traditional vent flapper, but remove the short duct that comes with traditional flapper.
I would like to talk to Broan about the problem but I'm sure they will turn a blind eye to it.
The dryer pumps out an awful lot of heat and the ducting is very short so I can see why freezing isn't an issue there. I have just renovated my basement bathroom and will be replacing the old metal flapper vent. I have decided to try one of the Eco-Vent's mainly because I won't need ladders etc to get at it if it freezes. The vent will be on the same side of the house as the dryer vent and just above grade so I am hoping that this location will work. I'll keep you posted. It will be a Nutone Bathroom Fan (can't remember the model number) so we'll see if the lower heat and higher humidity air causes the ball any problems.
As for condensation, I put P traps in the ducting to the gable end vents and condensation is not a problem. I have also seen suggestions for just ensuring a slight incline in the duct work towards the vent so if any condensation does occur it flows towards the vent and not back into the fan.
Will keep you posted
I start to get problems with the little flapper vents freezing at about -10C and below, but the windchills have been -50C on and off for the past few weeks so I really think that almost anything exposed would freeze in those sorts of conditions.
A question, would metal flappers be worse than plastic flappers? My intuition is that metal conducts heat better so would thaw out more quickly, or would that also mean they freeze more quickly?
Well I have a metal style flapper on my kitchen range hood, about 3x the cfm of my bathroom fans, but it froze earlier this year as well, didn't try to thaw it with the fan, just went outside and gave it a knock with the broom and all the ice fell off and its been fine since. The Ecovent on the otherhand I have even tried applying pressure to the ball with a screwdriver to break it free from its frozen seat, but to no avail, that thing is frozen solid. And due to the grill style "rodent protector" on the output, you can't fit a damn thing up inside to grab the ball (like your hand). I may try a heat gun along with the fan on later this week when the temps are forecasted for -1C. Once I break it free maybe it will work...I'll post the outcome...
Originally Posted by toonarmysk
I think its mainly because it is insulated. So it freezes before normal flappers would.