exhaust fan for breeding room

Matt Pedersen's talk at MBI had a room with an exhaust fan connected to the home's HVAC ductwork - does anyone have any specs on something like that?  My second dehumidifyer just died and I am looking to improve the system.
 
Thanks,
 
John

Hi John, although I can't help you with your idea I would like to throw another idea at you.  In my room, I have the air pump (65 lpm) placed outside of the fish room (still inside the building though) so the airstones are essentially producing a positive pressure in the fish room.  The door to the room is well sealed.  I installed a 1" pvc pipe through the wall to the outside with a flapper like a clothes dryer vent.  The positive pressure from the airstones flows out this 1" pvc vent I made and keep the humidity of the fish room around 45% which is the same as my house.  In this manner, I can achieve lower humidity and higher oxygen in the fish room without using any more power.
 
Just a thought... 

Don't let fear and common sense stop you! =]

 I run a normal bathroom exhaust in the basement fish room connected straight to a vent on the outside of the house. No real problems, but one of my walls is piled stones and dirt, so take what you will from that.

--Andy, the bucket man.
"Not to know the mandolin is to argue oneself unknown...." --Clara Lanza, 1886

I'm going to resurrect an old thread here. I'm going to be installing an exhaust fan with a humidity sensor on it in my fish room. I'm looking at a few and want to stay close to the $100 mark.
 
However I just read the second post here about an air stone and a vent.   Can you go into further detail? Pics? Would you mount it on the upper or lower side of the wall? What kit did you use?

RLTW

180 Gallon Mixed Reef

Then I heard the voice of the Lord saying, "Whom shall I send? And who will go for us?" And I said, "Here am I. Send me!" Isaiah 6:8

I had a 110cfm bath fan installed in the clownhouse attached to a humidty stat.  Usually the dehumidifier kept the room fine but there were times that when it wasn't running that the humidity would climb.  By setting the humidistat at 55% the fan came on and exhausted the air as needed.

I have quite a lot of water in my fish room (roughly 1,400 gals. including cultures and mixing water), plus one wall is dirt and rock. My one exhaust fan plus A/C keeps it quite nice in there (the A/C does not actually draw any air from this room, just blows in). It's normally very dry here, so the fish room is certainly more humid than the rest of the house but I don't really notice it much.

--Andy, the bucket man.
"Not to know the mandolin is to argue oneself unknown...." --Clara Lanza, 1886

All my tanks are in the basement. We cut a hole and installed a grate on the air duct return to the furnace.  While the furnace is running, or the air conditioner, the moist air is drawn into the system and out of the room.  Works well.  In addition, we have a small muffin fan in one of our windows that runs 24 hours a day/365 days a year. This does not affect the temperature of the basement, but it vents the humid air outside all the time, drawing in dryer air from the rest of the house.
 
In addition, I keep tanks covered.  Even a partial cover condenses water back into the tank, getting it out of the air, and saving you top-off water.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

I hope no one minds me reviving this thread again. Looking at options for dealing with humidity. The dehumidifier doesn't cut it. I'm considering a few ideas, and would love to get this communities thoughts.

I have one additional problem. I am discovering when the house is closed up, our co2 rises. We got a withings scale earlier this year with co2 sensor, and it's gotten as high as 2000ppm in the home. Which is great for my phyto, but not so great for me as a human being. 

So I've been considering a few things to try and deal with the humidity and the co2.

Exhaust fan. Our house is pretty leaky, so we should be able to pull air in from the outside. But there is a risk to this and that is negative pressure being created causing a back flow of carbon monoxide. I'm not sure how much actual risk there is, as it sounds like a lot of you are doing exactly that.

Heat Recovery Ventilator. Expensive, but brings in fresh air and blows out old air.  In this case, the old air would be the wet air. The fish are limited to a single room (right now) but the whole house does seem to have enough humidity that I suspect this will do a lot to help remove the damp air.

Kathy, the muffin fan you have in the window, did you build a fitting to set it in the window? 

Most everyone I know has used exhaust fans with good results.  I went the HRV route and wow, it does some amazing things.  I have the largest residential unit you can get, and if you're handy (I'm not) you can probably install it yourself for < 1K
 

Thanks for your thoughts. The more research I've done, the more I've concluded an HRV is the way to go, probably for the same reasons you like it. Much healthier air, for one. I've decided on attempting to build my own HRV, but making it window mount instead of furnace mount. Design similar to this: http://www.builditsolar.c...ntal/DIYHRV/DIYHRV.htm only instead of spacers, alternate the direction of the coroplast 90 degrees between each one.
 
A couple of diy examples:
http://ecorenovator.org/f...on-heat-exchanger.html (loooong thread)
https://www.youtube.com/watch?v=4FSewTEsGD8
https://www.youtube.com/watch?v=akkhDjxwIu0

In the meantime, I've just been using a window fan as an exhaust fan (pointed out). Which works well enough; but I'm going to want a better, insulated solution before winter hits. 

DIY HRV?  Wow.  I await the build thread on that!

I'll be following this with interest.  I've been too busy building the greenhouse to learn about HRVs yet, but when it starts raining indoors with 100% humidity in the winter I know I'll need one.  I see some priced in the $500 range with 65%-70% efficiency that have fairly high turnover.  
 
My question, are they controlled by a humidistat? 

Mine is controlled by a rather extensive digital controller, but it doesn't work the way you'd think.  For starters, it has min and max humidity points; the lowest I can set it is 30% (which is around where it sits all winter) and the "MINIMUM" high point is 65%.  It can also be turned off, set to run on a timer, or set manually on to a fan speed of my designation.  In the summer I either left it in the control mode or simply set it on a low, constant turnover more for ventilation than anything else.  In the winter, it's definitely on automatic to pull it down to 30% or close to it.

Thanks for the info.  With a greenhouse and a large volume of water I have nightmares about what winter humidity will do.  I'll see in a couple of months.  I don't see using the unit much in the summer in Virginia, I foresee just keeping screen doors open and fans running.  
 
I think a holistic strategy needs to be used: a second layer of plastic and covered tanks in the winter, shade cloth and misting in the summer.  It will be a learning experience.