[Delphinus]

You bet. You can count on bigtime humidity problems such as weeping windows in the winter, mildew forming on the walls and ceilings, particularly north outside walls of your house.

I ran a dehumidifier for many years, but the effect was localized and it's noisy as all get out. If you have a family, expect them to hate it.

I dealt with this problem with the equivalent of a BFG a few years ago. I installed central air and an HRV. You don't have to do the A/C, that's only for comfort and cooling in the summer, but the HRV is, in my opinion, what saved my house. I don't even have my 280 running yet - I just had evaporation from 3 reef tanks (110g, 75g and 40g - plus a FW tank I suppose too was helping add to the humidity) and it was causing HUGE problems. For me it came down to - consider the HRV, or consider quitting. Mildew on the walls, especially if you have a family - it's a no-brainer, you can't live with that.

If you're handy you can install one yourself. I believe BMWRider on this board did an install himself. I had a place that was recommended to me by Monza do mine - they did a whole analysis based on square footage, amount of air turnover required for the projected humidity, and came up with a unit sizing recommendation. I then asked them for the next model up just to increase my margin of error. Yeah, this was expensive (basically the cost of a nice large tank with all the trimmin's .. but .. like I said, it was this, or quit. And I figured since I was going for broke and they were going to tear my furnace ducting apart anyhow, might as well throw an AC on there. I have a south facing house and man did the house get hot in the summer. No more. Also no more heating problems among any of the 4 tanks. Sweet. No regrets.)

An HRV has other benefits. Now that I know what they are, I'd never consider living in a house without one.

What some people do is just vent the tank room with a bathroom fan or a furnace booster fan. This is OK in some circumstances, but it has a few drawbacks. One, you only vent air out. You rely on the furnace, and overall house leakage, and so on, to replace the air that is drawn out. Plus they are noisy (at least some are - my bathroom fans are horrendous, I'd hate to have to listen to that all day long).

An HRV (heat recovery ventilator) is basically a fan that draws air out - like a bathroom fan - but - it replaces the air it pulls out, running both streams through a heat exchanger. You recover something like 85%-90% of the heat of the outgoing air. This is important in our climate ... you'll be happy you're not pulling in air at -20 in those February coldsnaps.

It works to turnover the air volume in whole house so your air quality improves without costing you having your furnace run full time to heat the incoming air.

Anyhow like I said it is a very heavy-handed approach to eliminating humidity, but after a few years of weeping windows and mildew formation, I was ready for heavy-handed. Other people do make do with the bathroom fan vent solution, or the booster fan, but ... to me ... I think the real "once and for all" solution is the HRV.