Dehumidifier in a Fish Room

[MarkoD]

no i totally understand. because its not replacing moist air with the dry air, its just pulling more moisture from the rest of the house.

i just dont think theres any way for me to use this. the heat it produces raises tank temp to 81.5.

looks like ill just have to get an AC unit for the fish room.

[sphelps]

But it's not pulling "more moisture" than just a fan alone would. Unless you agree with that statement you don't completely understand.

If heat isn't an issue without the dehumidifier and you have a way of exhausting air outside from the fish room I'd suggest just using an exhaust fan to control humidity. By venting air outside you're exchanging air, new dry air will enter the room as needed from the rest of your house. No need for an HRV, it really won't help in summer months, only winter and more than likely humidity isn't much of a concern in the winter.

[MarkoD]

my issue is that that rest of the house is about 50% humidity. and id like to get my fish room down to 35% because its in the same room as the furnace,boiler, electrical panel.

a fan will just keep it at 50% like the rest of the house, right?

[sphelps]

Originally Posted by MarkoD

my issue is that that rest of the house is about 50% humidity. and id like to get my fish room down to 35% because its in the same room as the furnace,boiler, electrical panel.

a fan will just keep it at 50% like the rest of the house, right?

Yeah in theory but depends if we're talking about real humidity or relative humidity. We measure relative humidity which is a percentage of how much moisture is in the air relative to how much moisture the air can hold at it's temperature. So if air is warmer in the fish room which is typically the case due to equipment then your relative humidity could be lower than the rest of your house. For example 50% humidity @ 20°C is the same amount of moisture as 35% humidity @ 25.9°C

Now if you cool the air with an AC unit you will remove moisture but relative humidity may still stay the same or even increase.

50% relative humility is just fine for your house hold equipment. What you need to be concerned about is if anything the air in the room comes in contact with is cold enough to form condensation but @ 50% relative you'll need a 10°C temperature difference.

[MarkoD]

I don't really know the specifics. The room is naturally cool (3 exterior concrete walls and interior wall is insulated) and there are no windows. Running LEDs even as room lights to avoid introducing heat

My main goal is to keep the humidity in the room as low as possible to lower the risk of anything being effected by it.

In my old house. I noticed that drawer handles had started feeling rough (like sand paper) even tho they were about 20 feet from the tank.

[sphelps]

Would it not be more economical and practical to build some kind of enclosure around your tank equipment to separate it from your mechanical room? The enclosure could be vented separately and you eliminate all your issues and concerns. Keeping the whole room cold will only cut back on evaporation but won't necessarily make much of a difference to protect your house.

Exposed cold water pipes and your water meter are probably the biggest targets, every fish room I've seen that shares space with a mech room had corroded pipes. Next is the furnace ducting. But I think the issues relates to more to the type of evaporation, as salt seems to get evaporated as well it will cause damage much faster. Just sealing the room up and keeping it cold may not make a difference at all, better to have air exchanged. Your house air at 50% humidly won't damage anything, it's circulating through the furnace anyway and would damage other things in your house before your electrical panel or other mechanical room equipment.

Keeping it separate is best option but IMO the next best thing is general circulation. Keep the air exchanged reducing the amount of salt in the air, like I mentioned before this is done with a simple exhaust fan and humidistat.

[The Guy]

Originally Posted by sphelps

But it's not pulling "more moisture" than just a fan alone would. Unless you agree with that statement you don't completely understand.

If heat isn't an issue without the dehumidifier and you have a way of exhausting air outside from the fish room I'd suggest just using an exhaust fan to control humidity. By venting air outside you're exchanging air, new dry air will enter the room as needed from the rest of your house. No need for an HRV, it really won't help in summer months, only winter and more than likely humidity isn't much of a concern in the winter.

Totally agree with you. I run a 500 CFM exhaust fan, works great and the room air is replaced by the air conditioned area in my home.