Dehumidifier in a Fish Room

[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.