Humidity problems with large tank?

[airtime23]

Thinking of a 200-300 gallon reef in a second-floor study on a home that is currently being constructed.

Already have the subfloor plannned (per a structural engineer's recommendations in terms of weight).

Would that amount of water cause significant humidity issues in the room? The room is 20 x 20 ft. The builder is concerned that I might need a built-in dehumidifier for the HVAC for the entire second-floor.

Anyone have any experience?

 

[dave.m]

You can probably expect to lose 3-5 gallons per day to evaporation. You may not need to go the route of an entire dedicated HVAC system (although if you can afford it that would be nice, too). Depending on how you set the tank up in the room, you can duct air from the sump below the tank and from the canopy above the tank directly outdoors with a humidistat-controlled bathroom fan.

Dave.M

 

[rbarn]

Definitely need to do something. If it is rimless with no top canopy then you will need a whole house system, if it is going to have an enclosed top you can do an exhaust fan system just over tank to the outdoors.

 

[CyclistMT]

Thinking of a 200-300 gallon reef in a second-floor study on a home that is currently being constructed.

Would that amount of water cause significant humidity issues in the room? The room is 20 x 20 ft. The builder is concerned that I might need a built-in dehumidifier for the HVAC for the entire second-floor.

Anyone have any experience?

Yes, you will have humidity issues. I live in a super dry climate (Billings, MT) and I had humidity issues with a 150g (in the whole house). I have a gas forced air furnace (read- dries the air out seriously bad in winter) and with a humidity remediation strategy (humidistat controlled fan venting to outside) I still get some condensation on the window in the room my tank is in with my current 300g. But I don't see mold like I used to with my 150g that had no humidity remediation. Mold is the issue and the enemy when dealing with humidity.

A dehumidifier may work for you but if possible, I would recommend a strategy to move the humid air from the tank to the outside via a ducted fan dedicated to this purpose or an HRV. A dehumidifier typically works against itself- pulls moisture out of the air but adds head to the air which increases evaporation rate which increases moisture which....well, you get the picture. A dehumidifier can help but it's best to move the moisture somewhere else if possible.

 

[airtime23]

Thanks for the replies.

So if I went with a humidistat controlled exhaust fan, is that similar to the exhaust fans that are found in bathrooms? Are those really effective? Do they really move enough air to have an effect?

 

[skiwez]

they definitely move enough air you just need to get the right sized one. For my last build I bought a Panasonic HRV. It's dead quiet so far so good. If you don't want an HRV you can't go wrong with the Panasonic exhaust fans. I thought my electrician was nuts when he reccomended them for my bathroom remodel. After it was installed I was pleasantly suprised. moves alot of air with almost ni noise

 

[rygar]

Just talk to your HVAC guy. If he's good, he'll know exactly what to do...then you can concentrate on the fun stuff and not worry about this type of thing.

 

[vair]

If you are having a fish room (back room for sumps and equipment) a dedicated HRV for the room is the way to go. It works great.

 

[spsfreak1977]

Dehumidifier works very well for me

 

[ca1ore]

Not sure I agree. I have a 265 main display in my family room (also approx. 20x20) and have no excess humidity problems in the house. In the winter, tank evaporation maintains house humidity at about 35%; in the summer, my regular A/C system seems to have no problem maintaining comfortable levels - so you may be looking for a solution in search of a problem.

NOW, my basement fish room (where the sump is located) is a different story, and I do have to run a dehumidifier - but I had to do that before I had the big tank as well.

 

[Pife]

I would put a mini split system in that room so that you don't have any issues.

 

[sfsuphysics]

I'm going to hop in here. Is there a fan rating (for one that will be controlled via humidistat) rule of thumb for enclosed tanks/fish rooms? I'll have nearly 500g of water volume in about 320 cubic feet of enclosed area (although easily 1/3 of that is the tanks/stands/etc). Curious what sort of CFM rating I should be looking at so I don't undersize my system.

 

[nuxx]

Think it could depend on the type of equipment you're running...

While water testing my 600 gallon system a week ago, I was only seeing about 1/2 to 1 gallon of evaporation.

That was with no lights, a Jebao WP60 and two DC return pumps.

 

[sfsuphysics]

Hmmm that's going to make it more difficult to figure out, how am I supposed to know how much evaporation will occur? I'm not exactly able to add one after the fact due to the location of where it needs to go.

 

[nuxx]

I really don't see any tanks around here with anything more than the AC dealing with the tank.

I don't plan on doing anything with mine. It's going to have an open top, no canopy.

The room / area of the house is open and has 12' ceilings with 2-3 vents close to the tank and a return about 8 feet away from the tank as well.

 

[sfsuphysics]

Well there's no AC in San Francisco That said, mine is going to be completely enclosed, and I've had moisture issues as seen by condensation on windows before with tanks half the water volume in a nearly 400 sqft room.

 

[benihana]

My room will be just shy of 400 sqft, and from what I read, the preferred thought for bathrooms is 8x per hour of air replacement (room/7.5) which would mean that I would need a 53 cfm fan...my plan is to at least double, maybe triple that. Specifically looking at the 110 cfm or 150 cfm Panasonic bath fan....better to be too big than not big enough

 

[atreis]

Keep in mind the OP is in Charlotte - a location that gets quite humid for a substantial part of the year and not all that cold (usually) in the winter. It's not the same as northern states or the SW. IMO, venting would be best. BTW - someone else mentioned using Panasonic bathroom vent fans. I'll second that. In addition to being effective and very quiet, they also have continuous duty motors. Many bathroom vent fans don't.

 

[davebehlen]

My room will be just shy of 400 sqft, and from what I read, the preferred thought for bathrooms is 8x per hour of air replacement (room/7.5) which would mean that I would need a 53 cfm fan...my plan is to at least double, maybe triple that. Specifically looking at the 110 cfm or 150 cfm Panasonic bath fan....better to be too big than not big enough

Just install a very small window unit AC directly into your fish room wall....back side out in your basement.....

Put a drip pan/drain under the unit and drain out the humidity wherever you can....be a dump bucket or into a drain pipe.

The window unit does ALL the work of a dehumidifier and completely replaces those expensive chillers. Set your fish room at 72F and smile.

The AC unit is only displacing heat to outside the fish room just like a fan would with the added benefit of dehumidifying (accelerating evaporation cooling)....and little extra cost per KWh.

 

[davebehlen]

Just install a very small window unit AC directly into your fish room wall....back side out in your basement.....

Put a drip pan/drain under the unit and drain out the humidity wherever you can....be a dump bucket or into a drain pipe.

The window unit does ALL the work of a dehumidifier and completely replaces those expensive chillers. Set your fish room at 72F and smile.

The AC unit is only displacing heat to outside the fish room just like a fan would with the added benefit of dehumidifying (accelerating evaporation cooling)....and little extra cost per KWh.

To restate...a chiller in your fish room circulates heat in the fish room....and does not promote evaporation because it does not dehumidify, nor coo the room. A small AC to treat the air does both....removes heat and humidity, and you can trap the humidity of the condensate of the AC and remove it as needed.