Humidity issues with large tanks.

[sfsuphysics]

My tank is in my "basement" area (first floor of San Francisco style house, basically right off the garage at ground level, not liveable space unless you convert it to an in-law unit).

I have digital humidity stat, and it triggers at anything about 60% humidity and a Panasonic whisper fan turns on and pulls the air into an attached greenhouse and the plants love all the warm humid air that gets dumped in. Normally the fan turns on through out the day, sometimes the humidity is higher sometimes lower. The total tank volume is probably somewhere in the neighborhood of 600 gallons too.

Now there have been a few rainy days, and unfortunately the "basement" tends to get a lot more humid that normal naturally. Not to mention the pet door downstairs that often lets in humid air. So the problem now is there's not really any "non-humid" air to get pulled into the tank area when the fan sucks out the air near the tank, and now unfortunately the humidity is pushing in the 77-80% range which is way too humid IMO, I'm seeing condensation on surfaces I really don't want to see condensation on!

So my question is how can I deal with this? Setup a dehumidifier in the basement? in the tank area? I realize they're energy hogs but when it's dry outside this is not an issue at all, so hopefully would only use power during rainy season. I thought about piping from a not so humid part of the house, but then I don't want that area to become humid because it drifts through the duct work. Finding a way to seal up the "basement" would probably be ideal, but that is a long term solution, I'm thinking I need something fast. Any ideas would be nice.

[Darrell Brady]

I use a santa fe classic . there expensive though.

[sfsuphysics]

That's a type of dehumidifier?

[woodnaquanut]

A fan might help. It won't reduce the humidity but could get all the condensation up. Typically in greenhouses they want the humidity but w/o the fans it turns to wet, diseased plants.

The fan along with a dehumidifier and exhaust fan might do the trick. Run the fan lots, exhaust at a certain level and dehumidify (real energy hog) anything above your comfort level. You really don't want to suck in outside humid air if the dehumidifier is running!

Alternatively, install Tiki hut bar in corner and fire up some Bob Marley on the iPod. (known as living with the humidity). :)

[anbosu]

I would get a dehumidifier set up to drain outside or wherever and have it set to run when humidity gets over a certain set point.

[sfsuphysics]

Yeah that sounds like a good plan. Have the exhaust fan do most of the heavy lifting, then if it gets so humid even that can't keep up (wet winters) then the dehumidifier can kick in and hopefully take care of the rest.

Sealing up the room will be the long term plan, it's an old house in San Francisco, not exactly built to be air tight/energy efficient that is standard code today. I really hate that pet door and wish my cat wouldn't freak out and screech like a banshee if rooms get too closed off for her.

[dave.m]

Sealing up the room too tight would not be a good idea either, as you will then run into problems with too much CO2 in the air interfering with your corals.

Dave.M

[acabgd]

I would get another digital humidity stat and attach it to a dehumidifier with a higher setting than your fan. This way if your fan doesn't do the job, the dehumidifier will, but it will not run the whole time and you will save some electricity.

[jarvis]

I would get a dehumidifier. Its an energy hog, but its only a seasonal problem your having

Can you pull in air from an inside living space?, a lung room would help the condensation, but yours can be sealed from the outside environment if your not having heat problems....if so you can re-route your intake during the season and close off your intake from outside. Add a fan re routed back into the living space that has good airflow to disperse the humidity and better yet it adds heat to your living space of your house.

[FishTruck]

I have a Sante Fe dehumidifier in my basement (open sump, skimmer, etc...) running for about 7 years now. All wood and metal down there is dry with no condensation.


It is fairly loud though, I would not want it in the same room as my display... but they can be used remotely if you have room for some duct work.

[sfsuphysics]

I think the Santa Fe is a little out of my price range.

Unfortunately, finding a dehumidifier (at least a 70pint one) is becoming difficult, all the local big box stores are completely sold out. Guess I'm not the only one who has humidity issues, when it rains :)

[slief]

I have a 480G display with about 650G total water volume. This is located in my house. I have an exterior wall that is next to the tank so I used a 10" rotron high CFM industrial fan fan that ducts air from above the tank to the outside of the house through a vent.

In this picture, you can see the 10" hole in the light soffit above the tank. On the other side of that wall is the 10 fan. The fan is shrouded by 10" duct which goes through the closet and connects to the exterior wall vent.
http://i390.photobucket.com/albums/oo347/shleif/Tanks/lightstop.jpg

You can see the exterior wall vent here in the upper right corner above the shed. The vent has a hinged door that closes when the fan isn't on. I keep this fan on 24x7 and it elminates most if not all humbity generated by the tank. It not only draws from above the tank but it also pulls air through the wall from below the tank where the sumps are located.

In a basement, a simple fan on the wall behind a vent would be plenty to pull the humidity out of the room and keep it at manageable levels.
http://i390.photobucket.com/albums/oo347/shleif/Tanks/DSC01775.jpg

This is the duct that goes from the fan to the exterior vent.
http://i390.photobucket.com/albums/oo347/shleif/Tanks/DSC00440.jpg

[Sk8r]

Basement sump. With library and fabric storage. I use a fairly inexpensive (ca. 200.oo) Whirlpool rollabout dehumidifier. You have to empty the bin--couple of gallons is its cap. But it works.

[teo241]

I had the advantage of knowing where the tank would go when our house was being built so I splurged for a heat recovery ventilator. Have a dehumidifier running to a floor drain for back up. Basement stays 68 degrees year round at about 50% humidity.

[YesYouCan]

or just keep the room as close to the tanks temp as you can - this will reduce the condensation. My Fish Room is always about 75 while my display room is about 60 in the dead of winter. I do run exhaust and intakes and average about 20 gals a week lost but im also dealing with about 40sqf of open water to air contact.

[JCURRY@WESKETCH]

Get a split system for the room. Air conditioning cools a room by dehumidification and you get the benefit of cool air instead of the hot air from a dehumidifier.

[sfsuphysics]

I have a 480G display with about 650G total water volume. This is located in my house. I have an exterior wall that is next to the tank so I used a 10" rotron high CFM industrial fan fan that ducts air from above the tank to the outside of the house through a vent.

I have a fan that pulls out the volume of air like every few minutes (I forget the exact rating, but it's not as beefy as yours). The problem is the air that's replacing it is almost as humid, so it's really a losing battle.

or just keep the room as close to the tanks temp as you can - this will reduce the condensation. My Fish Room is always about 75 while my display room is about 60 in the dead of winter. I do run exhaust and intakes and average about 20 gals a week lost but im also dealing with about 40sqf of open water to air contact.
Ideally this is what I want, and was the plan when I built the tank, large volume, temperature of the tank warms the air, enclosed to that heat gets trapped and I spend less trying to heat the tank. And I have about 54 sqft of open water to air contact... so yeah I get you with replacing water like crazy.

Get a split system for the room. Air conditioning cools a room by dehumidification and you get the benefit of cool air instead of the hot air from a dehumidifier.
I don't want to cool the room though. I don't live in an area where over heating is an issue, in fact just the opposite, and cooling the room with the tank would translate into spending more energy heating tank.