How do you handle heat and humidity for your monster tanks in the midwest?

[FishTruck]

I am still trying to figure out the optimal way to manage heat and humidity... where I live bitter cold and blistering heat both happen.

Right now... I have a 200 cfm fan pulling the humid air off the display tank and dumping it into the fish room. The fish room has both a big dehumidifier and a window AC unit - both were running 24/7 for July, August and September so far. The fish room temp never got below 74 and the humidity was stuck at 55 - 60%. Tank temp is stuck at 80.7 degrees. Dealing with about 1500 gallons of water with open tops.

My next move is to put the exhaust out the window (this will remove 200 cfm of hot humid air from the equation) with an intake vent to passively take in outside air to make up the pressure gap. I also want some fresh air in the fish room to help keep the tank pH above 8.0 as much as possible.

Any other suggestions on how to do this more efficiently? Have any of you tied in to you home HVAC?

 

[New Jersey REEF]

I used few fans over the tank to cool it down and multiple dehumidifiers, 3 in all. Separate HVAC unit where I run room temperatures at 72 year around. Tank temperature stays at 78-79.

 

[eric.tech]

Maybe look into an HRV/ERV air exchanger? Would probably help get some fresh air in without the bitter cold of the winters up north.

 

[AlexG]

There are a few things to consider here. Do you have some pictures of your fish room wide angle shots that show floor to ceiling? How are you measuring humidity levels? Electronic monitor if so does it have a 24hr high/low reading? What are the humidity levels reading in the rest of your home, the fish room, and the humidity over the display tank? Seeing this comparison might help in determining some solutions. Is the dehumidifier in the fish room exhausting into the fish room? If it is you might want to consider exhausting the dry warm air of the dehumidifer outside of the fish room into another part of the home. Are there any open top tanks than can have a cover added such as sumps or other filtration tanks? Humidity levels in the 55-60% range are not too bad and that level will fluctuate based on the amount of evaporation and temperature in the room. An exhaust fan to the outside is a good option. Bringing in fresh air can help as long as its not going to make the humidity or temperature situation worse which is where a HRV/ERV air exchanger would come in handy.

 

[FishTruck]

There are a few things to consider here. Do you have some pictures of your fish room wide angle shots that show floor to ceiling? How are you measuring humidity levels? Electronic monitor if so does it have a 24hr high/low reading? What are the humidity levels reading in the rest of your home, the fish room, and the humidity over the display tank? Seeing this comparison might help in determining some solutions. Is the dehumidifier in the fish room exhausting into the fish room? If it is you might want to consider exhausting the dry warm air of the dehumidifer outside of the fish room into another part of the home. Are there any open top tanks than can have a cover added such as sumps or other filtration tanks? Humidity levels in the 55-60% range are not too bad and that level will fluctuate based on the amount of evaporation and temperature in the room. An exhaust fan to the outside is a good option. Bringing in fresh air can help as long as its not going to make the humidity or temperature situation worse which is where a HRV/ERV air exchanger would come in handy.

That's the type of information I need to gather and decide which air to put where. Right now... the fish room is taking the hot moist air from the upstairs display tank... the evaporation from four open top boxes (2 sumps and 2 grow-out tanks), and the hot air from the dehumidifier.

I'll work on making a schematic with the relevant numbers. Here is what I have so far.... the dehumidifier is out of view.

 

[Pistondog]

I am still trying to figure out the optimal way to manage heat and humidity... where I live bitter cold and blistering heat both happen.

Right now... I have a 200 cfm fan pulling the humid air off the display tank and dumping it into the fish room. The fish room has both a big dehumidifier and a window AC unit - both were running 24/7 for July, August and September so far. The fish room temp never got below 74 and the humidity was stuck at 55 - 60%. Tank temp is stuck at 80.7 degrees. Dealing with about 1500 gallons of water with open tops.

My next move is to put the exhaust out the window (this will remove 200 cfm of hot humid air from the equation) with an intake vent to passively take in outside air to make up the pressure gap. I also want some fresh air in the fish room to help keep the tank pH above 8.0 as much as possible.

Any other suggestions on how to do this more efficiently? Have any of you tied in to you home HVAC?

"Pulling the humid air off the dt..."
The fan should be blowing on the watersurface for evaporative cooling.
It makes a difference, try blowing out a candle by sucking air.

 

[AlexG]

After looking at the picture I think that a ducted dehumidifier might also be an option as it could be placed outside the room and the display tank could be ducted directly to the dehumidifier. Then the AC unit in the fish room will not be fighting the heat output of the dehumidifier and also provide some dehumidification in the space.

Its hard to tell but it looks like the sumps do not have covers along with the frag tanks that are not in operation. I would get covers on those to prevent excess moisture from getting into the fish room. I kept covers on all of my sump tanks for my displays and they made a big difference in preventing excess moisture from getting into the room especially the sump tank that was where the main drain and skimmer were located. Once you have some humidity values from around the different points you can get a better idea if you are controlling the humidity of the system effectively. As an example my fish room which also enclosed the display tanks would have humidity that ranged from 45%-65% depending on the time of day and season. In the rest of the basement outside of the fish room the humidity remained in the 30-40% range. I kept a negative pressure in the fish room so the air that exited my fish room was either exhausted outside or was pulled into a dehumidifier that was situated outside of the fish room and connected via a duct.

 

[FishTruck]

"Pulling the humid air off the dt..."
The fan should be blowing on the watersurface for evaporative cooling.
It makes a difference, try blowing out a candle by sucking air.

I took the fans off the sumps because it seemed like I was just making the dehumidifier work harder... which was putting heat back into the room.

After looking at the picture I think that a ducted dehumidifier might also be an option as it could be placed outside the room and the display tank could be ducted directly to the dehumidifier. Then the AC unit in the fish room will not be fighting the heat output of the dehumidifier and also provide some dehumidification in the space.

Its hard to tell but it looks like the sumps do not have covers along with the frag tanks that are not in operation. I would get covers on those to prevent excess moisture from getting into the fish room. I kept covers on all of my sump tanks for my displays and they made a big difference in preventing excess moisture from getting into the room especially the sump tank that was where the main drain and skimmer were located. Once you have some humidity values from around the different points you can get a better idea if you are controlling the humidity of the system effectively. As an example my fish room which also enclosed the display tanks would have humidity that ranged from 45%-65% depending on the time of day and season. In the rest of the basement outside of the fish room the humidity remained in the 30-40% range. I kept a negative pressure in the fish room so the air that exited my fish room was either exhausted outside or was pulled into a dehumidifier that was situated outside of the fish room and connected via a duct.

I can cover the two sumps... and dump the air from the display outside. This would, in theory, reduce the evaporative effect by up to 78%. The air exchange would be 200 cfm out and 200 cfm outside air in. That part, would be a bit of a wild-card depending on outside air conditions.

 

[Pistondog]

I took the fans off the sumps because it seemed like I was just making the dehumidifier work harder... which was putting heat back into the room.



I can cover the two sumps... and dump the air from the display outside. This would, in theory, reduce the evaporative effect by up to 78%. The air exchange would be 200 cfm out and 200 cfm outside air in. That part, would be a bit of a wild-card depending on outside air conditions.

Yep thats the battle.
But, evaporation cooling is the least expensive method.

 

[New Jersey REEF]

Look into this unit, I love mine. Gives me insight on air quality in the fishroom. I got it mainly for co2 monitoring but it does give additional info on dust and humidity.

Awair Element Indoor Air Quality Monitor

 

[FishTruck]

I tried a few different things and combinations and I have the summer settings greatly improved. Thanks for all of your suggestions.

1. I Vented canopy air outside at 200 cfm (the canopy air was 87 degrees at 55% RH), I set the dehumidifier to 60%. I was able to cut the dehumidifier run rate from 100% to about 50% of the time. No change in tank temp or fish room temp or RH in the fish room. Score. This partly solved the battle between the AC unit and the DH unit.

2. I turned off my skimmer pump (Danner Magdrive 24), this dropped the tank temp by about 1/2 degrees. A bit underwhelming, but notable. I'll get a cheap DC pump to replace the Mag Drive (reducing 240 watts to 80 watts of submerged pump) - but not until next summer.

3. I put a fan blowing over the top of the tank (12 foot run), and continued venting this outside. Tank temp dropped by 2.5 degrees in 24 hours! Wow! Once the air temp dropped to fall weather, the tank temp continued to drop - so last night I had to turn off the fan when the tank hit 77.6 degrees.

So... big improvement. I cut the electricity use, and dropped the tank temp by 3 degrees overall. Next summer, should be much better. I still have the option of covering the sumps.

Now... to see what happens with cold weather!

 

[BackToTheReef]

I am still trying to figure out the optimal way to manage heat and humidity... where I live bitter cold and blistering heat both happen.

Right now... I have a 200 cfm fan pulling the humid air off the display tank and dumping it into the fish room. The fish room has both a big dehumidifier and a window AC unit - both were running 24/7 for July, August and September so far. The fish room temp never got below 74 and the humidity was stuck at 55 - 60%. Tank temp is stuck at 80.7 degrees. Dealing with about 1500 gallons of water with open tops.

My next move is to put the exhaust out the window (this will remove 200 cfm of hot humid air from the equation) with an intake vent to passively take in outside air to make up the pressure gap. I also want some fresh air in the fish room to help keep the tank pH above 8.0 as much as possible.

Any other suggestions on how to do this more efficiently? Have any of you tied in to you home HVAC?

Mini split HP (both heating and cooling) and an ERV. If you are exhausting warm, moist air and doing nothing to the incoming "fresh" air then you are potentially just replacing humidity with slightly less humidity. An ERV will dehumidify the incoming air as well as exhaust the humid air. You can set them up as a balanced system and adjust ventilation rates as conditions change. The ERV also has a heat exchanger so in the winter you aren't bringing in 30 degree air and in the summer you aren't bringing in 100 degree air.

The mini split will add super efficient heating and cooling (depending on where you are. If in a cold climate go with a hyper heat model). It will add air movement as it is constantly circulating air, and some dehumidification as well. If you get a multi zone system you can add a couple of heads depending on how the space is situated and already heated/cooled. Allowing the Fish Room to be controlled separately. That head could be "cooling" that fish room 24/7 while the rest of the house is on the your normal schedule.

 

[FishTruck]

Mini split HP (both heating and cooling) and an ERV. If you are exhausting warm, moist air and doing nothing to the incoming "fresh" air then you are potentially just replacing humidity with slightly less humidity. An ERV will dehumidify the incoming air as well as exhaust the humid air. You can set them up as a balanced system and adjust ventilation rates as conditions change. The ERV also has a heat exchanger so in the winter you aren't bringing in 30 degree air and in the summer you aren't bringing in 100 degree air.

The mini split will add super efficient heating and cooling (depending on where you are. If in a cold climate go with a hyper heat model). It will add air movement as it is constantly circulating air, and some dehumidification as well. If you get a multi zone system you can add a couple of heads depending on how the space is situated and already heated/cooled. Allowing the Fish Room to be controlled separately. That head could be "cooling" that fish room 24/7 while the rest of the house is on the your normal schedule.

That would be the Cadillac setup! I was not aware than an ERV could dehumidify the incoming air - at least not in the summer time. By heating cold air through the heat exchange... it would do that in the winter.

I am doing the ghetto version right now with trial and error. I can either vent or save the hot air from the canopy (depending if it is winter or summer). The outside air is very useful in the spring and fall, not so much in the summer or winter - and I am guessing an ERV would extend the usability of the outside air significantly.

I am also venting in fresh air to clear the CO2, which raised the pH of my tank by about .1 or .2.

Considering how many kids are leaving bathroom fans on all over the house - I figure the incoming fresh air might as well comin in through the fish room.

 

[vetteguy53081]

I had the same issue with my 660g and as soon as i instaled a chiller- Complete 360 turnaround. Tank always 78-79 deg and no humidity !

 

[BackToTheReef]

That would be the Cadillac setup! I was not aware than an ERV could dehumidify the incoming air - at least not in the summer time. By heating cold air through the heat exchange... it would do that in the winter.

I am doing the ghetto version right now with trial and error. I can either vent or save the hot air from the canopy (depending if it is winter or summer). The outside air is very useful in the spring and fall, not so much in the summer or winter - and I am guessing an ERV would extend the usability of the outside air significantly.

I am also venting in fresh air to clear the CO2, which raised the pH of my tank by about .1 or .2.

Considering how many kids are leaving bathroom fans on all over the house - I figure the incoming fresh air might as well comin in through the fish room.

You can get away with a Honda Civic package as well. There are some really good/efficient mini split DIY install kits out there that still get you efficiency and a bump in heating/cooling.

HRV (Heat Recovery Ventilator) will not deal with humidity while ERV (technically enthalpy recovery ventilator but everyone says energy) will dehumidify the incoming air, as well as "condition" it temp wise...warm it up in winter, cool it in the summer. Panasonic was making some affordable versions that could handle high humidity environments.

If you set the fresh air outlet to discharge in front of the tank and the exhaust intake in the hood or behind the tank in the fish room you will also be creating a small negative pressure that will help move air in the direction you want as well. Also increasing the dehumidifying affects.

 

[BackToTheReef]

I had the same issue with my 660g and as soon as i instaled a chiller- Complete 360 turnaround. Tank always 78-79 deg and no humidity !

What size chiller did you use?

 

[FishTruck]

What size chiller did you use?

... and... how did it cut down on humidity? Did you then cover up all the open water... or did it cut down the evaporation rate from the water being cooler?

 

[emvanburen]

Good thread- learned a lot. I am venting my tank air straight outside all the time. Using an apex controlled fan across the water surface to manage temp. It is extremely effective as you reported. Fish room has another vent fan going up the unnecessary radon stack. Debating adding a dehumidifier. Humidity runs about 55. Would like to drop it some.