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

[jakano]

Ok I never did respond to this but I only have one pvc run going to the furnace and I know that it is the exhaust. So it sounds like I am out of luck on using this mod for my humidity problems. Any one have another suggestion that might work for me? My basement is starting to smell really musty and my tools are rusting so I have to do something soon.

[wmilas]

You might not want to hear it but the only surefire way is a multi-approach system:

1) Build a fish room. and contain the air. If not treat the whole basement as the fishroom, but its more costly energy wise.

2) Install a ventilator for the basement. This can be a HRV, or simply 2 fantech fans on 6 or 8 inch. One needs to draw air from outside, one needs to exhaust air to the outside. You MUST have Makeup air or bad thigns will happen, trust me. These (or the hrv) run when its cool outside and/or when the realitive humidity outside is less than inside. How these are plumbed into your fishroom basement depends on the setup. In a fishroom, isolate it from your hvac completely. In a basement isolate it, or add it in, choice is yours. The dual fantechs are a poor mans HRV in essence, or are a hrv that doesn't retain the heat which might be preferable in your neck of the woods.

3) In a basement, install a dehumidifier. Install a whole house one if you can, and if your hvac actually pulls air from the basement. The dehumidifier is used in the summer during the day when the relative humidity outside is greater than what you are trying to flush out. In a fishroom you don't have to do this if your room is setup properly and doesn't leak air. You can simply flush air via the fantechs.

4) In a fishroom install a split AC system separate from the HVAC. In the basement you probably wont need this as the dehumidifier can't kick out enough heat if its a portable model, and if its a built in model to your hvac it will kick heat out of your condenser outside. The split AC unit will not be used in a fishroom except to take the air temp down if its interfering with heat buildup in your tank. The fishroom isolates and contains the humid air letting you flush it when you want, at night, ect. The trade off is it can get hot in there during the day, and you might have to cool it. The energy for the slight cooling, if its even needed, is far less than having to run a dehumidifier in a whole basement.

Basically, its haphazard with a basement. You waste alot more energy removing the humidification than in a fishroom because you can't isolate the target humidity and flush it. If you have a tank thats big enough to cause humidity problems in a basement, you really need to build a fishroom, or a canopy over it that is airtight and you can control directly with makeup and exhaust air, or with direct dehumidification. Just installing a dehumidifier only masks the problem and is going to be more $ in the long run if you want to take the basement humidity down an appreciable level from a large tank in a basement.

In summary: fishroom: install makeup and exhaust fan system, install split ac if its needed. Flush humid air when it makes sense for you.

Basement: Install dehumidifier, install fantech/hrv system to cut costs and get cheap dehumidification when able based on outside situation AC normally wouldnt be needed.

Fishroom wins $ wise as far as energy savings go... dehumidifiers eat tons of current.

[jnarowe]

all I have in my tank room is a 6" exhaust fan and an attic style vent allowing fresh air to come in from under my deck. Sometimes humidity gets high because it is humid outside, bit it does work in a pinch for many locations.

[Oldtimer]

I agree with wmilas, although I think you can get away with one fan and a vent like Jonathan mentions as long as the fishroom is sealed, because the air will passively enter or exit the vent (depending how you set it up) as the fan does the opposite.

FWIW - I will be using an HRV and mini split A/C in my fish room. I do not want a humidifier because the heat it generates will be an issue in the relatively small fishroom and it will end up driving the A/C to stay on. I also intend to have a chiller located outside the fishroom. I plan to toy around with the chiller and A/C duty cycles to see what works best.

[wmilas]

Originally posted by jnarowe
all I have in my tank room is a 6" exhaust fan and an attic style vent allowing fresh air to come in from under my deck. Sometimes humidity gets high because it is humid outside, bit it does work in a pinch for many locations.

Thats an even cheaper version of the fantech, you have makeup air via the vent, and exhaust via the fan. Either way, same idea. I just through the fantech thing out there in case the fishroom isn't on an outside wall, or if its not an outside wall you want to drill through.

[jnarowe]

yeah, and my set up is by no means the best method, but it is a good place to start for a sealed tank room. I still have humidity issues at times and that can really mess with metals in the room.

[wmilas]

Right, but its contained to that room, and you can make the decision to spend more on energy to preserve the metals, or remove the metal, or whatever. Its much more flexable than the basement/nonfishroom situation. Cheaper too

[jnarowe]

I would never do the "basement" thing. Too risky IMO and I don't want my house to rot.

[chriscobb]

I know this is an old thread, but trying to find a practical, economical solutions for humidity control for my fishroom....The new tank is roughly 350 gallon display and 157 gallons. The fishroom itself is 12x15, and I already have ductwork installed to exhaust humid air to the outside. Should I install another duct to bring air in or draw air from outside the fishroom as the fresh air source?

I should add that I installed vapor barrier to all the walls and ceiling and used Dense Armor drywall.

The house is total electric with heat pump, so I'm taking it no ill affect from negative pressure. Should I add air ducts from the viewing area as well?

[jnarowe]

Ultimately is comes down to how much humidity you are experiencing, and how much you can afford to correct it. If you cool your tank via evaporative cooling, you will see a lot more humidity than using a chiller. Something to think about though, is that it is very nice to get "fresh" air into the tank room. I don't know what the weather is like in PA, but that is a major factor in deciding to use indoor makeup air, or outdoor.

Bringing in fresh air helps a lot to stabilize ambient CO2 & O2 and I believe that is key to a healthy tank.

[chriscobb]

Thanks....here in PA we have a short period of humidity, but not extended periods of time....The tank and fishroom will both be located in the basement which is totally finished and is the family room.....Adding a chiller wouldn't be an issue, but was trying to cut energy costs, so was thinking that just adding another duct to pull fresh air in might be the better of the 2 options.....I'm looking at installing the Hydrofarm ActiveAir Blower fan which is rated at 465 cfm. I know this is overkill for the size room.....

[jnarowe]

that's about what I did but with higher CFM, believe it or not. I had mine set to room temp. because ambient humidity is high here in the Northwest. But, it's my experience that using this method of cooling will give sporadic results. In other words, in my tank room, humidity could often climb higher than what I could remove, due to ambient conditions. I did use a marine dehumidifier as well, but getting a commercially rated one is also something to consider.

Next time around, I will cool my tank with a ground loop, and greatly reduce the amount of humidity I am adding to the room.

[chriscobb]

I've had tanks before in my family room itself and never had any issues with keeping the tank cool or humidity, but going with a larger volume of water I want to try to be ahead of the game....I have a 1hp chiller from my last setup, but would just hate to have to go back to using it....Actually with my last setup in the family room I had more issues with heating the tank......So with running an exhaust and intake in addition to a dehumidifier is it possible to control the humidity issues?

[jnarowe]

I would think so, but again, it depends on so many variables relating to your system and tank room, it's hard to know without trying. Seems like you have everything you need, and you can always phase in cooling and air exchange elements as you see how the system operates. If you are worried about making the hole, you can go ahead and do so before you set the tank up, using a plug/cap, so if needed, you have it ready without disturbing a running system.

[chriscobb]

I think making the hole is my issue???? Sounds rather stupid, since I've already done and installed the one...My issue is space is tight with the deck and all, and probably would only have a 1'-3' feet between the vents....Would that create an issue?

[bbrantley]

It's going to boil down to how much outside humidity you have (percentage and duration). I know it can get pretty humid in the northeast in the summer time. If those periods last longer than a few days, you will need to use something besides evaporative cooling to keep the tank temperature stable. During seasons where the outside humidity is pretty low, you can get away with fans for cooling and exchange with the outside.

450cfm doesn't sound like all that much to me. You (or a consultant, including some that will do it free for you) can do the thermodynamic calculation based on heat you're putting into the tank and the humidity and temperature deltas to determine what flow rate you'll need to evacuate the extra moisture. It goes up pretty significantly if you have a slightly higher humidity outside, so take care!

My tank room is about 16 x 18, I have 1000 system gallons, the outside humidity is never above 30% and often closer to 15 or 20%, and the temperature outside is always below my desired tank temp of 78F. With what are pretty much perfect conditions, I run two 450cfm fans (pointed one each way) and see duty cycles of about 50% during peak warm days.

One side problem I have is that the system doesn't know how to handle rain and snow. In those conditions, the "humidity" goes way up and the fans can get stuck in a feedback loop, bringing more and more water into the fish room. Since we don't get extensive rainy periods, it's never been a big issue.

Just seat of the pants, I would guess you could stay comfortably passive for at least 50% of the time. You'll probably still need the equipment to cool actively some subset of the remaining time, and then there'll be this middle ground where it'll work but have an aggressive duty cycle. It's certainly worth considering, if only for the electricity savings!

Good luck.

[chriscobb]

Thanks for the info....this is the fan/blower I'm considering....
http://www.amazon.com/Hydrofarm-Acti...=2NDEGP8CU1WUH

[bbrantley]

For reference, I used Fantech TD-500s.

[jnarowe]

Originally Posted by chriscobb

I think making the hole is my issue???? Sounds rather stupid, since I've already done and installed the one...My issue is space is tight with the deck and all, and probably would only have a 1'-3' feet between the vents....Would that create an issue?

Yes & no. I had my intake and export right next to each other. My intake was just a passive attic vent under my deck. Outbound I added piping outside to run the exported air about 15' away from the intake. Of course, I could only do this because of the tank room being adjacent and lower than a huge outside deck.

[phillyfishguy]

I am in the process of building a tank room with my sump and other tanks. My main display tank is in my living room. My basement is open to the rest of the house via stairs. I have an old home but also have attic fan vent. I have gas hot water and gas boiler uses flute. I wonder if I could draw the air from the basement and vent the air outside via bathroom fan. I was going to leave it open to the rest of the basement just now confused to maybe close it up lol

Not a huge amount of water in the basement 48X18X18 sump 30 gallon and a frag tank plus qt tank but not up all the time. Never had a saltwater tank so not really sure. Great thread by the way

[capncapo]

How big is your tank?

[sfsuphysics]

wow thanks for the bump... I'm going to be in the process of doing a "fish room" (few months out however at a minimum) and venting is on my mind. I'll bring details back later, but I do have an outside wall I can drill through, so figured tossing one of those "quiet" exhaust fans to blow everything outside might be great hooked to a humidistat with temp & humidity controls, but was curious what is an "acceptable" level of humidity? Hopefully the temp will be in the 80 range, so I don't have to use heaters too often (chilling the tank will not be an issue)

Was a tad worried about input air though, the room will be (hopefully) sealed up tighter than a frogs butthole (insulated too ) but I'm worried put a vent (even if its low) might defeat the purpose of me building a room to purposefully trap the heat to save money on electricity (to heat the tank).

Also would it make any difference between long cycles or short cycles of the vent system? I mean I know start up current would add a bit of stress, but was wondering if that really makes a difference. Or would they typically use the same amount of energy either way.

[jnarowe]

Mike, you have to be very careful about employing a humidistat in your venting system. My experience was with fresh outside air as the replacement air, and often times here in the NW, it was humid air inbound, and my vent fans would cycle on and off repeatedly. Ultimately I disabled the humidistat function and just had it come on at a set temp. You can see pictures on my web site, but the nut of it is, you have to have replacement air, and where it comes from, completes your equation.

[phillyfishguy]

120 gallon in my living room rest in basement

[capncapo]

Originally Posted by phillyfishguy

120 gallon in my living room rest in basement

I think I'd watch and see if you have any issues. Your system is not all that large and your house can probably handle the humidity.

Older houses seem to have quite a bit of outdoor air infiltration which can keep humidity levels in check in the cooler months and your A/C
( if you have one ) should handle it in the warmer months.