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

[capncapo]

There was a HVAC "show" here in St. Louis about a month ago.

While attending, I stopped by the booth of every manufacturer who makes ERVs and asked them about their products. Not a single one of the reps could tell me that they recommended using an ERV in my area because of the high humidity levels in the summer.

ERVs should not be trying to dehumidify the air from the house. They should be trying to dehumidify the incoming air while also trying to exchange the heat to the outgoing air.

On another note....those who are concerned about harming their furnaces should not be worried about it unless they are drawing salt spray into their ductwork. As long as the return is far enough away from the tank, the possibility of salt getting into the ductwork is very minimal. Salt doesn't evaporate along with the water.

[steve the plumb]

humidity will ruin a furnace.My gas furnace was 6 years old and was rotted out due to humidity in the room.My tank is no where near the furnace room and I have radiators (old home) for some reason there is humidity in my furnace room and my furnace didn't last as long as it should have.I will place a dehumidifier in the furnace room because I already see that I am getting a white residue on my new furnace(this is what happens when the furnace room is humid) the furnace will have to be cleaned.I don't know why this is happening but the fish room is a concern to me in the summer.

[capncapo]

Furnaces in places like New Orleans stay in humidity like that the whole time that they are used. Seems like most of the ones I've seen down there are mounted in the attics of homes and because of that are in high humidity and heat year round.

[Oldtimer]

<a href=showthread.php?s=&postid=11130364#post11130364 target=_blank>Originally posted</a> by capncapo
ERVs should not be trying to dehumidify the air from the house. They should be trying to dehumidify the incoming air while also trying to exchange the heat to the outgoing air.

That was exactly what I had i mind, but the reps' feedback is consistent with the feel I got from everything I've read about ERV's. I also read a bit about the saturation of the dessicant that wmilas pointed out. I have yet to run this one by my neighbor, but I suspect his feedback will be consistent with yours. My idea was to reduce the load on the more expensive to operate A/C in the summer months.

I'm leaning towards the following...
* A dedicated A/C unit for the basement with ducting in the equipment room and near the tank
* An HRV for the equipment room
* Vents with adjustable dampers to regulate air passively betweeen the equipment room and living space
* No dehumidifier
* Possibly a chiller, but probably try to run without one at first
* Possibly a duct from the equipment room into the furnace return ductwork (assuming I'm convinced that it will not destroy my furnace) - In my mind this is not required with the HRV, but would allow me to distribute the humidity throughout the rest of the house during the dry/cold months
* A controller to regulate everything as seemlessly as possible

[capncapo]

Why would you want to run a Heat Retaining Ventilator in summer? They are designed to do just that....retain heat in the house.

A separate mini-split system can definitely help.

A duct into the return of your furnace will help also but I would recommend that you also run a supply from the furnace into the fish room just to "pressureize the room a bit. It will help the return to draw air better.

I'm not a big fan of running dehumidifiers in the summer. They create unnecessary heat.

While vents with dampers between the fish room and living space may make the fish room a bit more tolerable you'll just be spreading the misery to the living space.

[capncapo]

Duplicate post :D

[Oldtimer]

My idea was to run the HRV in the winter since cool/dry air is plentiful then. I thought of having an ERV (vs. HRV) for the summer based on this quote until I saw your feedback...

"The most popular design of ERVs utilizes a desiccant
wheel to remove both heat and a significant amount
of moisture from the incoming air, which reduces the load
on the air-conditioning system."

I'll plan to run both supply/return if I route fish room air to the furnace - thx.

My concept of installing the vents between the equipment room and the rest of the basement is to have the option in case I ever need it but ultimately keep air flowing through the room to avoid pH fluctuations. Perhaps there's a more efficient way to do this - ? I guess I don't expect the A/C to be working all the time.

[capncapo]

The best way to keep the pH fluctuations in check is to have a fresh air intake.

Something you might want to consider is having a small intake that would supply air to your skimmer only. It could possibly raise your water temp a bit but could be well worth it.

[Oldtimer]

<a href=showthread.php?s=&postid=11131665#post11131665 target=_blank>Originally posted</a> by capncapo
The best way to keep the pH fluctuations in check is to have a fresh air intake.

Something you might want to consider is having a small intake that would supply air to your skimmer only. It could possibly raise your water temp a bit but could be well worth it.

Never considered that, but it makes perfect sense. Thanks!

[wmilas]

Everyone agrees that an air conditioner, if you can afford it is great because it both lowers temp and lowers humidity. Great.

The problem arises with the dehumidifier. In a partly cold climate there are times when the air outside is both cold and too humid. Its in this case when the dehumidifier is nice... I think.

As why use a hrv instead of a simple vent? Well in the wintertime the HRV is a big winner. In the summertime the HRV will hardly be used because its most often more humid outside.

That leaves spring and fall. In these cases if its less humid outside and cold and you need to dump heat also, the hrv will be sub-optimal, but will still work, will just need to run longer to dump the heat. I think mine is a 85% efficient model, which seems to be pretty up there. Run it long enough and it will eventually dump enough heat. Mine is fairly cheap to run. Internally there is just a blower and thats it. While a simple vent would wok better we are looking at another two holes in the brickwork for that ontop of the two holes for the hrv, ontop of the hole for the ac unit, and another for the electrical to the condenser.

As far non corrosion of the AC unit I'm still worried about this. Yes I know that only water evporates. The problem is that I was Chemical Engineer for a short period of time (lasted all of 2 years in schooling :) and I know that its entirely possible for salt water to vaporize into tiny bubbles and float about. The more agitation the more likely this is possible. This is where salt creep comes from when its 10 feet away from your tank :)

Now I could put a foam filter on the intake to catch most of this but we are talking mold central, plus I still am not keen of same of the salt making it into the HVAC ductwork. It gives me the willies.

Am I missing something?

[capncapo]

To each, their own......

While I don't live on or near the coast anywhere I would think that it would be a common problem in those areas and we'd be hearing from folks saying much the same thing.

[capncapo]

One could always use the very same set of holes used for the
HRV with a vent fan. Should be easy enough to make the transition.

[wmilas]

Good point on the vent holes.

How would you plumb existing hvac into a dedicated sealed fish room and when would the vents be open/run considering a powervent unit?

All the time in the summer obviously, but when in the spring/summer/winter?

[capncapo]

I'd take a 6" supply and return run and tap into the trunk wherever I could for the "plumbing".

Like I said before, the vents being open would be on a day to day basis depending on the weather.

[Nanook]

What's up old man:D?

[capncapo]

I'm sorry, you obviously have me mistaken for some older gentleman.:D

[capncapo]

Another double post.

[Nanook]

I should have called you an OLD DOG:lol:

[capncapo]

Now if I were an old dog I would think that I might be making a puddle on your living room rug. Lucky for you, I'm not!:D

[Nanook]

Bogie would chew you up and spit you out:D

[capncapo]

I've never seen Bogie spit ANYTHING out! :D

[atvdave]

first, I stumbled across this thread doing a search on dehumidify.

Capncapo, sense your in the HVAC industry I was hoping you can help me.

I built a small insulated sump box in my garage. I ran my supply & return pipes through the wall to get rid of the sump noise in my living room.

Just after 2 week I have water beading up and running out of my sump box and the wood is just saturated with water. For some dumb reason I never thought about venting out the moisture.

NOW.. My sump box is right next to my HVAC unit in my garage. I have gas heat, and the unit also has a hole house humidifier installed on the return line. I can easily disconnect the humidifier if need be, I really don't need it. Is there a way to connect my HVAC into my sump box to keep it somewhat dry?

Will the gas heat do anything to my tank? or will the humidity do anything harmful to my HVAC system?

My garage is not insulated and my kids keep the garage open most of the time. With that said my garage get very cold in the winter, and very hot in the summer, I really don't want to vent my house heat, or AC out in to uninsulated garage.

Do I have hope or should I just bulldoze the sump box and put the sump back under the tank stand?

Thanks for your time
Dave

[jakano]

Hey Cap Quick Question for you. I read this thread but I noticed something odd. In one portion you mentioned this would work with a 90% efficient furnace but in a totally seperate posting you say that a furnace with this rating will do nothing to reduce humidity in your home.

My furnace has an energy star rating of 92.3 so I assume this is its efficiency, which means this mod will do nothing for me. Is this correct or am I missing something? My basement is getting a little damp and this sounded like the perfect fix for me but I'm not sure i can do it now.

[capncapo]

SOME 90% furnaces get their exhaust air from the inside of the the home while others have an intake that brings fresh air in from outdoors to be used as exhaust air. Some can be set up either way.

If you pull your exhaust air from indoors you will be getting rid of some humidity but I wouldn't rely on it being anywhere near enough to eliminate a problem.

If you have only a single run of PVC going to the outdoors then you're using indoor air for exhaust. Two runs indicate that you're bringing fresh air in to be used as exhaust.

I'd be looking at an HRV if I were you....or at least a vent fan and fresh air intake.

[jakano]

Thanks I Cap Ill have to check that out when I get home. I know I have a single pvc run to vent the exhaust gas but not sure if I have two or not.

[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]

<a href=showthread.php?s=&postid=12567269#post12567269 target=_blank>Originally posted</a> 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-ActiveAir-Blower-Fan-465/dp/B000CRICRY/ref=wl_it_dp_o?ie=UTF8&coliid=I1R0HTSKF7AU2X&colid=2NDEGP8CU1WUH

[bbrantley]

For reference, I used Fantech TD-500s.

[jnarowe]

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 :D) 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]

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.

[phillyfishguy]

I think I will put some sort of air venting system in the basement. I have access to put outside vents in so still researching (semes like thats all I do lol )

[sfsuphysics]

Jonathan: Hmmm good point about the replacement air. The room is downstairs in my "basement" its a finished room circa 50s/60s probably built without permits (just a guess unless plumbing codes changed dramatically, i.e. requiring air vents for each drain), and was thinking and yanking incoming air from there. Had a friend do it with just a thermostat and says it works fine, I'm a tad more worried about humidity issues than temperature ones, but who knows, maybe it'll balance out in the long run that the temperature being vented will keep the humidity in check (however I would think the night time humidity issues might then become problematic).

Hell I might be able to pull air from upstairs too, but I really would like a flapper that closes off when air isn't being pushed out. Although I would think a vertical air pull might end up having all my heat go that direction

[phillyfishguy]

Not sure if you can but if you had a bad drain problem you could pull water in if you didn't pull from the vent high enough but not sure. I could be wrong