Ventilation

[shipwreck]

Hoping we might have some HVAC experience here to help out.  So in my new fish room/laundry room I installed two 80cfm exhaust fans each controlled by a dedicated de-humidistat.  The room is only about 1000ft3 so these fans can really move the air from the space when required.

The problem I realize is that the room does not have 160cfm of air entering for the turnover as the room is too well sealed. If I crack the door the humidity will drop in minutes and the fans will shut off but with the door closed it builds and the fans run continuously. Since the other side of the door is becoming the adult living room I want to keep the door closed to keep the fish and laundry noise contained.

What I'm looking for is a method to get air into the room. I can pull air from the house if there is a way to do it quietly. I can also do it from outside but want a method that isn't just whole in the wall that rain, snow, wind or critters will just rip through. The room has no forced air registers would they be easy to add and not sure even possible.

Any suggestions?

 

[phi delt reefer]

homes in the UK have this issue regularly so they seem to have the best selection of products to deal with this issue.

http://www.vent-axia.com/range/vent-axia-freshvent-natural-ventilation.html

have a look at the link i posted. I think it's what you're looking for. It does require drilling a hole in the exterior wall but as you can see it looks nice and neat and would keep critters out and only open when the switch is activated.

I did notice you have a window in your fish room. Could you possibly retro fit a louvered fan that is controlled by the humidity controller? you would not need to pull the window out but you might need to build something out of plywood to fill in the space not covered by the fan. Similar how an window AC is installed.

 

[shipwreck]

The link doesn't seem to work.

As for the window I am looking for a more permenant solution. I may need to use those in the summer as well as I do have window mounted fans that can move massive air through the room if it gets too hot.  Or will use the window for the exhaust pipes of a standalone ac unit.

 

[phi delt reefer]

link works fine for me (though it could be stored in my cache) - it did take about 10 seconds to load though...

 

[sunnykita]

the link worked for me too

 

[AdamS]

You said it works fine with the door open? Undercut the door by an inch or so.

You dont want cold air coming into that room in the winter, it will get awefully cold. Or you could cut a return air grill into the door / wall. If you put a piece of duct on the opening it will really help to deaden the sound.

The more i think of it, put a return airgrill in the wall with a piece of flexible duct connected to it.

 

[reefin]

Hoping we might have some HVAC experience here to help out.  So in my new fish room/laundry room I installed two 80cfm exhaust fans each controlled by a dedicated de-humidistat.  The room is only about 1000ft3 so these fans can really move the air from the space when required.

The problem I realize is that the room does not have 160cfm of air entering for the turnover as the room is too well sealed. If I crack the door the humidity will drop in minutes and the fans will shut off but with the door closed it builds and the fans run continuously. Since the other side of the door is becoming the adult living room I want to keep the door closed to keep the fish and laundry noise contained.

so with these fans you have in the room where do they exhaust to?

It sounds to me like you just have these fans moving air in the room and its not going anywhere just in the room. The problem with cracking the door to the living room is the moist air is then push thru the rest of the house and that's why the humidity drops.
So my question is......Do you have a dehumidifier in the fish room and a floor drain in there as well this would help with condensation thru out the house and if your room is that sealed off would be able to keep it low in there with the door closed with very little noise and CT had the 50 pint on sale for I think $189.00 but there are several used ones around.
The next thing to look at is a little more money but worth the cost IMO and that would be a full air exchanger unit that would do the entire house.

 

[Duke]

They must be exhausting outdoors.. That's the impression I got, you just need a place for air to passively be drawn into the room, privacy vents on the door would work.. Similar to an outhouse..

 

[shipwreck]

The link worked this time.  That is the type of thing I'm looking for. The only problem is that says it is for possitive pressure. Since my fans draw air from the room and push it outside they create a negative pressure in the room.

I do not have and do not plan to use a dehumidifier in the room as it will generate unnessary heat in the room.  Also since there is no forced air heating an HVAC system will not work either.  I previously had as much or more water volume in the house without an issue. The rest of the house is an old (100+ years) farm house which is drafty and very dry. The fish room is built using modern methods with no drafts. Cracking the door draws the dry house air into the room.  This why I am looking for a way to bring in fresh air to the room ideally from outside or he main house.

I am not concerned about drawing in cool air into the room as I feel the amount requires will be minimal and with the heat generated by the tank, the washer and dryer and the rooms dedicated heating there should be no major issues.

 

[shipwreck]

They must be exhausting outdoors.. That's the impression I got, you just need a place for air to passively be drawn into the room, privacy vents on the door would work.. Similar to an outhouse..

Correct!  The entrance door for the room is glass so no venting options. I used vents on my kast build through the wall from the fish room to the adjoining room. For ventilation they did work very well as intended. The problem was that that in the room they vented too I could hear all of the tank noises. Standing beside the tank I couldn't hear the noises.

 

[reefin]

Accually the air exchanger unit doesn't rquire a full HVAC system as it is a stand alone system.

 

[AdamS]

If both 80cfm fans came on, an entire air change would take 6.25 mins. Bringing in -10c air would make that room real cold, real fast at 4am when the dryer usage is less than peak. I would be careful when bringing in outside air.

 

[phi delt reefer]

sounds like a single room HRV is the way to go ($$$) ... OR deal with the noise.