Wouldn’t the noise of the dehumidifier in the living room bother you? How would you empty the container?

@User It doesn't both me personally... drain-tiles were installed 1-2 days ago so maybe that's not enough time to say if it bothers me yet.

Ideally what I'm trying to learn is how much dehumidifier is needed for a townhouse... one per floor or just one big one in the basement to handle the whole house. Good dehumidifiers are pricey after all.

I think you should only need a dehumidifier for the part of the house that is humid, i.e., underground. Your heat and air conditioner should keep your humidity lower upstairs.

Using a dehumidifier upstairs has decreased my AC use (& electric bill). Amazed at how much water it pulls from the air. Hygrometer target 40%.

Thanks @User and @mdln

Further research found this post on another site: http://www.city-data.com/forum/house/1290727-does-basement-humidity-affect-upstairs-living.html. In summary, humid air is less dense than dry air. As a result, humid air rises. (This is why second floor was more humid than my basement). Based on that post, I'm going to put a 50 pint in the basement and my 30 pint on the second floor. This way, humidity is tackled as it goes from basement -> main floor -> second floor -> roof.

is it a stand alone unit? Just asking because I know nothing about HVAC, but I’ve never seen a 30 pint dehumidifier in someone’s living area except the basement. Or do you mean one of the whole house dehumidifiers?

This is the 70-pint one I have upstairs.

@User My fault... my living room has a 40 pint, not 30 pint. It's portable; maybe I have my placement of dehumidifiers wrong, hence my initial post (https://www.amazon.com/Waykar-Dehumidifier-Basements-Spaces-Manual/dp/B081RG8JYR).

@mdln I've got the same toshiba... put it in my basement (https://www.homedepot.com/p/Toshiba-50-Pint-115-Volt-ENERGY-STAR-Dehumidifier-with-Continuous-Operation-Function-TDDP5012ES2/310365942). Do you run it 24/7 and have a desired humidity level? The fan is somewhat loud, and it runs for a few minutes extra once the desired humidity is reached.

(Paid the same price as your 70 pint but got a few rebates, so it's ok a good deal)