<a href=showthread.php?s=&postid=10343299#post10343299 target=_blank>Originally posted</a> by overanalyzer
I like the moisture lock black plastic but I don't see an exhaust fan are you putting one in that room to the outside or did I miss it?
Thanks. It actually turned out better than I expected.
Humidity concerns are one of those things you never worry about until you have an ungodly amount of water volume. I would estimate that the costs incured trying to deal with the humidity would shock a lot of people (it surprised the hell out of me.) Here is an incomplete list of some issues that humidity has forced on me: 3 exhaust fans, replacing a window, a chiller, special circuit for a chiller, a humidistat, tons of venting, all the electrical consumption, the room moisture barrier, building a wall to separate the fishroom, buying reflectors with vents.
Keeping the humidity from getting to other parts of the house was a big concern. I didn't want to pay what it would cost to get some fancy solution to seal the fishroom, so I decided to go with plastic instead. The plasitic is thick and fairly strong. It is advertised as being good as a moisture barrier, but time will tell if it is. Each 8ft wide sheet of plastic is stapled to the rafters or wall frame. I overlayed all the edges by a couple of feet so that the seams would not be a major source for leakage. I know that there are a ton of small areas for moisture to escape the room, but I don't think they will be a problem. The reason for this is that I will have a number of exhaust fans running. All those fans will be expelling air from the room. I hope that the make-up air will be supplied through all those little holes, and the a/c vent in the ceiling. A perfectly tight room would be problematic, and so would a very open room. I think I may have struck the right balance. This is an issue I will make sure to report on thoroughly as the thread continues. Moisture problems were one of my top concerns when deciding whether or not to build this system. If I planned to stay in this house forever, I would definitely have simply built a room onto the house, with a separate ventilation system from the house.
As of now, I am planning on 3 exhaust fans. I may end up needed more or less depending on the results I experience this winter and next summer.
1.
I will be using a bathroom fan, controlled by a humidistat, to exhaust air outside. The humidistat will not be connected in any way to the aquacontroller. That way, if the aquacontroller were to fail, the room temp should protect the tank temp from getting too hot. (I don't worry about cold because corals can survive quite a temp drop, but they can't survive just a small temp increase.) I will tweak the humidistat setting until I find a good balance between tank evaporation (which will increase as room humidity decreases), the amount of time the chiller needs to run (which will go up as tank evaporation decreases), and house humidity (which is obviously the most important concen.)
2.
All of the Lumenarcs are going to be connected to a vent system. That system will be on whenever the halides are. Since the halides are the greatest source of heat for the tank, it makes sense to deal directly with their heat, instead of letting them heat the water and then try to deal with cooling the water (which is more difficult). I am concerned about very hot days outside, when it is hotter and more humid outside than in the fish room. On those days, the air exuasted by the bathroom fan (1.) will be cooler than the air from outside that replaces it. This won't be the case for the halides' vent. Since the air will be running over and around 4 X 400+ watt bulbs, it will always be really hot.
3.
Although the chiller cools the water running through it, the chiller will produce a lot of heat. That heat will then heat the surrounding air, which will then heat the tank water. So, the chiller directly cools the water but it indirectly heats it. To try to diminish the indirect heating that the chiller causes, I am going to exhaust the chiller's heat to the outside as well. The chiller will simply have a fan that sucks its exhaust air outside. The fan will be controlled to be on when the chiller is.
Those 3 methods are my main line of defense to keep the tank cool. I am sure that I will also be running a fan or two over the tank to help with the heat, but fans blowing across the tank work via evaporative cooling, and humidity is as great a foe as the heat itself. Therefore I don't want to use fans as the primary means of temperature control (although I have always exclusively used them on smaller systems in the past.) As I install these diffferent systems, I will make sure to document them thoroughly. I intend to have all 3 in operation by the time the tank is truly operational.
I hope that helps,
Brad