Large Tank IN a Basement-Ventilation Suggestoin Please oh brethern of the mamoth tank

[capncapo]

Negative pressure should not be an issue with that setup.

[hdtvguy]

okay thanks for the response.

[dgasmd]

I sincerely apologize in advance for replying to this thread before reading the entire thing. After having 2 larger tanks and set ups (360g tank/550g system and now a 750g tank/1000g system) I have come to what I believe is the best solution, long and short term, for humidity issues. Although I do live ina very hot climate all year round, I will include what to do for winters also for the folks living in the cold misery, I mean wonderful and gorgeous snowy, winters.

1. Isolate the entire system as much as posible fromt he rest of the house. I could not stress this enough. My current tank is inside the house now, but the only way it has ocntact with the air inside the house is via the air that gets drawn from inside the house to the above the tank area, which also gets fanned out to the garage where the equipment is. This is best for warm climates because you will be drawing cool air from inside the house above the tank where is hot and humid and blowing it in terms to the garage. For winter months, you may want to ahve a way to bypass the inside air going above the tank for air coming from the outside instead. Do the same for the filter or equipment room.

2. Cover your sump completely if at all possible!! Up until not too long ago, I was a huge fan of cooling with fans. I even have a huge fan blowing above the sump area. this causes a good amount of evaporation (10-12 gpd in my case) that can be replaced with cheap kalk and helps well with heat. The huge downside to this method is that you create an aweful large amount of humidity that settles in cooler surfaces (dew) causing a huge amount of rust and humidity damage. Even if you vent well the room where the equipment is, there will be significant humidity damage. Example is my own. I ahve all of my equipment in my garage, which remains open during the entire day for air exchange. If that is not sufficient air exchange,m I guess I don't know what is. Regardless, I close the garage doors during the night. In those 6-7 hours per night that the garage door remains closed, it has been enough to cause humidity damage to the wall behind the equipment and it has rusted every single thing that has even as much as a micron of metal in it. For somparision, a friend in similar climate and with all the equipment and tank in his garage has not a single sign of rust anywhere. The main difference is his sump is completely covered. He does not even open the garage doors, but does ahve a fan changing the volume of air in the room about 4-5 times per hour, which in my book is a far cry from leaving the doors opened completely. Most people with larger tanks will still require a chiller, as I and my friend do. In winter time, this is even worse as everything is cold and the humidity will settle on everything making it look like it rained isnide the house. I do believe the fan cooling has a place in the hobby, but it is most helpfull I think for smaller set ups or sets ups where the down sides have been addressed well and it prevents you from having to run a chiller at all.

Hope this is not repetitive to what already been posted.

[hawk66]

Dgasmd, I agree seperating the tank from the rest of the house seems the best approach. After many delays I have spent the past few day's doing just that for my new 375. Insulation for noise, vapour barrier,green board, and caulking all joints. I have installed a bathroom fan on the exterior wall about 2' from where the closest mh will be. I'll have 2 or 3 small fans at the opposite end/middle of the tank to ventilate some of the daytime heat. I also installed a ventilator fan thats contolled by a humidistat. I expect this to run 24/7 so I installed a fresh air intake ducted to the opposite end of the room as well. I will also install an adjustable vent in the door to see if I can draw from the basement as well. My gas water heater is in the fishroom, it needs to be replaced anyway so I'm changing it to electric to avoid negative pressure concerns.

[kwl1763]

SO here is my latest concern. I've done what I can so far. I have 2 cold air intakes above the tank (450G 10ft long), the tank itself is in it's own room that's walls, floor, ceiling, doors and stand are all heavily coated with marine waterproof bildge paint. I'm covering the 300G worth of sumps, chiller is outside and plumbed through the wall.


The last step I want to do is put a fan to draw air from the room to the outside using a humidistat. The only issue is that I'm in Atlanta. Many of you have heard it called Hotlanta which is really a misnomer. It should be called humidlanta! SO half the time the humidity outside will be at least as bad as the fish room.

My idea was to get 2 wired humidistats and plug them in parralell. One says if the inside gets above x then turn on, the other if the outside is below that x-10% turn on. That way the fan would not turn on unless the humidity outside was lower then the humidity inside.

1) Does that even make sense to do?

2) Is there a cheaper way? Those wired humidistats are like $200 each

[capncapo]

I'm sure that something like that would be possible but what you're going to try to do could prove to be a problem.

Something to consider is that 10% humidity at 90 degress is not the same as 10% humidity at 80 degrees. Warmer air can hold more moisture than air at a lower temperature.

If you could find a humidistat that will compensate for the temperature differential then your idea would have some merit.

[bbrantley]

capncapo,

If you're still up for it, I'd love your input on my humidity concerns. My environment is slightly different from some discussed here, and it may in fact be somewhat advantageous, but I'd like your take. I just posted to my young build thread describing my scenario, so I'll replicate it here for convenience:

Okay, I'm really ready now for some input on the ventilation in the room. Here are the relevant facts:

1. The tank and all supporting equipment will all be in one 200 square foot room.

2. The room has two windows to the outside and will be sealed off from the rest of the house with a weather-stripped door and moisture barriers behind all the walls, floor, and ceiling.

3. The room has radiant floor heating; there are no ventilation ducts anywhere in the house.

4. It's easy for me to cut holes in the side of the room that vent to the outside.

5. I live in a dry climate (Colorado) at 8,500 feet. It is consistently cold here in all but the summer months, and it is relatively cool in the summer -- never more than 80F and typically about 45F at night.


Given the above, what are my choices for managing heat and humidity? I've read about HRV's, simple exhausts, active air-conditioners, eco-coolers, bathroom fans, and more. It's a little overwhelming and kind of hard for me to understand what's really effective. My priorities are, in rough order, quiet, energy efficient, inexpensive, and easy to install.

Any thoughts from you or the group at large?

Thanks very much,

Ben

[Whaledriver]

You could get a fan controler that starts and stops a fan based on temperature and humidity

[capncapo]

Ben,

Having vents to the outside that would be manually opened, closed and adjusted when necessary would satisfy just about every one of your criteria and you didn't mention the word automatic.

Placing one of the vents low and the other high will make for a natural flow of air into and out of your room with no noise.

[bbrantley]

Originally posted by capncapo
Ben,

Having vents to the outside that would be manually opened, closed and adjusted when necessary would satisfy just about every one of your criteria and you didn't mention the word automatic.

Placing one of the vents low and the other high will make for a natural flow of air into and out of your room with no noise.

Thank you both for your replies -- I did forget "automatic," but not for lack of wanting.

This is what I was coming to suspect, but it's nice to hear my suspicions confirmed. Thanks.

Ben

[tye_c]

I am planning on installing an exhaust fan. Could I just Tee off the output to the return and to the outside? Then have manual shut offs on each? This way I can run the exhaust to the AC in the summer and winter and to the outside in the spring and fall.

[Whaledriver]

I wonder if any of the aquarium controller people can control a ventilation system? Instead of a chiller they can turn on a ventilation system?! Can you get a humidistat in these controller type systems?

[ellisz]

Ok, I am re-visiting this thread now that I have my 300+ system up and running. I have a 100 gal sump, 33 gal refugium and a 100 gal frag tank behind my 180 gal display. I have a 85 gpd dehumidifier that can get my humidity down to 43% but due to the settings on the unit, it has to run continuously. If I use a lower setting, it maintains 53%. Temps at 53% are 73 and temps at the 43% are 79.

I do have a return vent cut into my HVAC unit to help suck some of the humid air out. I also have a 4" vent fan that I use to blow air out of the house.

Would it help to cut another return? The room is about 10'x30' and is unfinished. I never really noticed a big difference after I cut the return in. I do keep my house fairly warm during the day so I wonder if my AC is not running enough? I can cut another return but due to the layout, it would be about 3-4ft from the other one unless I extended it with some flexible duct work.

Any ideas? I just want to keep the dehumidifier from running 24/7 and to keep the humidity to 45% or less.

[capncapo]

Installing another return vent could help but if the A/C doesn't run enough it may not help as much as you would like. Placement of the second vent is not critical. Just try to place it high so it is getting the warmest, most moisture laden air. Make sure that you put a closable vent on it just in case you decide that you need to draw more air from the other returns.

If your outdoor humidity levels are high then your vent fan could be working against you not to mention that you could be bringing in air that is warmer than what is already in your house. Either way, you should have a fresh air intake to prevent from creating a negative pressure situation and to allow the fan to work at its maximum potential.

Personally, I would run your A/C more during the day. At least you would be keeping the house cooler and reducing evaporation a bit. Your dehumidifier is costing you money to run and costing you money when your A/C has to run to cool the additional heat created by the dehumidifier.

[ellisz]

The sump room is in a unfinished part of my basement and the tank is in the basement as well. Temps are in the low 70's as it is now. I would be happy if the return would at least compliment the dehumidifier. I will go ahead an cut in another vent to see how it works.

Might even see about a new dehumidifier. I hate the fact that I can't dial in the humidity. I would be happy with 45% but I don't even know what the shut off on the high setting? The medium is apparantly 53%.

I have been considering putting up 2 walls to help contain the humidity and make the sump room smaller. I would have to put a vent in there as I am sure it would make the room hot with the dehumidifer in a smaller room.

[zachtos]

Any more ideas? I have the same problem now. 300G upstairs, 300G downstairs. I am now running a dehumidifier 65pt 24/7 and only able to maitain at 60% humidity, no lower. I am thinking of putting in a bathroom exhaust fan in the basement that vents outside controlled by a humidistat. I dont think I'll install a intake fan though, not sure what negative pressure will do yet either. I live in michigan, humid summers, dry winters, average fall/springs. Summer time was no issue because the AC ran all the time (which it still felt very humid in my house 1100sqft not including bsmt) I am going to try covering the sumps today, hopefully the tank wont get too hot... but I HAVE TO find something, the floors are starting to warp, the doors wont close in my house... it's a very big problem and it could cause me to have to shut the $10K + system down!!!

[FishTruck]

Hi Zack. Wathching your build with great interest. Here is what I am planning for my tank. The idea was stolen from Hop. Basically, I have a sealed hood over my tank, and a sealed cabinet around my equipment. I am going to vent the system with outside air, totally isolated from the house. I also have a big dehumidifier in my basement, but, want this running as little as possible.

Managing the system during extremes of outside temps and humidity will be the challenge.... but since it is isolated from the house... I really only need to worry about the temp of the system and lights.

Ryan.

[capncapo]

Zack,

You might want to look into an HRV if you want to retain the heat.

If you don't, a ventilation fan with a fresh air intake will do you good. Negative pressure could become an issue unless you have an electric hot water heater or a furnace that doesn't use a normal flue ( something like a pressure vented unit that has a fresh air intake ). The fresh air will do your system good as it will help to keep CO2 levels low which will help keep your pH stable.

[jnarowe]

Check my web site for how I deal with this. I agree with dgasmd
that salt/humidity damage can be a pain. I fully isolated my tank room from the rest of the house and installed an exhaust fan pulling air from above the tank and venting it outside. The return air is an open attic style vent under my deck which allows cool air to replace the exhausted air.

I also installed a temp. & humidity controller on the exhaust fan but ran into trouble because being in the NW, the outside air is sometimes more humid than the tank room air. So what happened is the humidistat was cycling the exhaust fan all day and night. I just turned off that part of the controller.

It can get humid in the tank room so I occasssionally adjust the temp setting. The big mistake was that I installed stainless work tables and a refrigerator in the tank room, and they will oxidize fairly easily. When I go to remodel the tank room, I will pull out the SS stuff and replace it with laminated wood.

Anyway, I find this method to work well considering how cheap it is to run. I do cool my system with blowers and that does cause the humidity to jump as stated earlier, but I can live with that. I also painted the walls and ceiling with yacht bilge paint, so there is no issue there.

[bguile]

I'm hoping I can get some assistance in this thread from the HVAC expert. Here's a pic of what I'm working with:


If you look closely, you can see that there is a duct feeding a/c and heat to the living area upstairs. Can/should I able to cut out a section and add a register for helping to cool the tank area during the summer months?

I am also planning on adding a bathroom type vent in the ceiling that will vent outside which is just a few feet to the left, will doing these two things be an issue for negative pressure? If so, how is it different from having this same type setup (vent and fan) in a bathroom. I'm all confused on this negative pressure stuff.

BTW, the dimensions of my area are 6'x6'x8'. The tank will be enclosed in a wall but not totally sealed off from the rest of the house. I plan to install a louvered door to access the room which is off what will later be my office.

This is the view from the front and back.


The blue floor area is what will be the equipment room.

Thanks.

[Whaledriver]

It seems to me that making use of household air can only lead to problems. You have humidity, smell and rust issues. Even if the outside air is warm the air in the hood is always over a hundred with the lights on so any new air should cool. With high enough airflow the evaporation should effect should help cool more.

My ideal system would have a variable speed fan controller that would speed up until the exit air hits a set point.

The second part would have a heat recovery system to use the heat from the exit air to warm the house in winter

[bguile]

Originally posted by Whaledriver
It seems to me that making use of household air can only lead to problems.

How so? We dont setup isolation systems for smaller tanks, say 120G, so that none of the "house" air moves about the tank. In fact, most of the time that same air is being used by fans and the like to help keep the water cool via evaportation. Why would it be different because I'm putting the tank behind a wall?

Originally posted by Whaledriver
Even if the outside air is warm the air in the hood is always over a hundred with the lights on so any new air should cool. With high enough airflow the evaporation should effect should help cool more.

So are you saying that maybe I could install an air vent or something to the outside to allow cool air in the room in the winter months?

[Whaledriver]

The more tanks you have the more smell that happens. You might not notice it but aquariums add a smell to a house. Ask someone who visits. Most of the time its not bad but it is a smell none the less. Smell your skimmer cup?

A heat recovery air to air exchanger will allow you to use the heat in the winter.

If you have a lot of tanks the humidity becomes a major issue so having the hood air separated from the room also prevents this. I have read a lot of threads about rust an mildew to ignore it. With a bright lighting system you can loose 3% a day to evaporation. With a 1000 gallon tank system that's 30 gallons a day in a 22 x 22 basement a DAY!

The design I have planed but not built is similar to FishTruck but I would run 2 ducts behind the tanks to feed new air and exhaust air. The system would have air tight hoods to separate all the air from the room. Matching intake and exhaust fans should keep the air pressure neutral.

[jnarowe]

I have a 1000g tank with 1000W lamps and it only evaps about 12g/day. But, rust is still an issue. I have stainless tables in my tank room and they rust up. Mold is not an issue in my case, but if my tank were open in my house, it would be a serious issue for sure.

[bguile]

Originally posted by Whaledriver
With a 1000 gallon tank system that's 30 gallons a day in a 22 x 22 basement a DAY!

Well it's a good thing I only have a 210 then and my plan is for the air to be taken OUT of the tank room to the outside, not blow it back into the house. So again, I don't see how drawing air from the rest of the living space INTO the tank room and out through a vent fan is a bad thing. I understand moisture in the air being a bad thing and cause for rust and the like, but I'm not blowing it into the living area.