Basement Ventilation
Hey
We are finishing a basement in the north east, hot humid in the summer cold and dry in the winter. We have created a tight envelope with XPS against the walls taped and foamed, same in the rim joist area. Additional insulation will be added to the framing. The basement has several small operable windows however we want to mechanically ventilate the basement (eg an ERV) and also control humidity. Are there any units that can do both or do we need a separate ERV and dehumidifier? If we need separate can they be staked to run on the same ducting or stand alone is best? Lastly, we could also install a wall hung mini split heat pump to help condition the air in summer and provide heat if needed in the winter. I would appreciate best practice options.
Thanks
Ben
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
BenNZ,
Be sure to read this article (and check the sidebar links) if you haven't done so already: https://www.greenbuildingadvisor.com/article/how-much-fresh-air-does-your-home-need
You might consider the Panasonic IntelliBalance (latest series) as a ventilation solution. If you have high indoor humidity levels, you should attempt to resolve those without dehumidification if possible. If mechanical dehumidification is your best option, you could install an Energy Star dehumidifier along with the Panasonic unit (or another ERV/HRV). Another option is installing an UltraAire (not UltimateAir) ventilating dehumidifier.
Steve,
Thanks for your reply. I will look at those products now. I could not see a link to the article you were referencing, apologies if I am missing it.
The humidity levels in the house are not bad but it can be outside in the summer time, that said with lots of kids down there we want to take the opportunity to build in systems now to deal with any problems in the future.
Thanks again Steve,
Ben
Ben,
Sorry. I edited the post and added the link.
Thanks again Steve. Much appreciated.
Ben
Another thing to look at is the Build Equinox CERV (https://buildequinox.com/thesystem/)
I haven't installed one, but when I talked with them they said it has enough dehumidification to remove any humidity in the makeup air. If there is a humidity load beyond that it may not be enough.
It is pricy though.
A post on the company's website suggests about $6,000 plus labor. I'm guessing that's about twice the cost of an ERV/HRV or a ventilating dehumidifier. Still, it looks like an elegant solution, and I like the CO2 and VOC monitoring feature.
Proper ventilation is something that is needed even in a not well sealed house.
Ventilation is something you design for the whole house, not just the basement.
https://www.greenbuildingadvisor.com/article/revisiting-ventilation
An ERV will make humidity issues in the house worse when it is hot and humid outside, it just brings in less moisture than an HRV. It won't dehumidify your basement. If needed, the typical solution around me (Toronto) is a stand alone dehumidifier.
You can definately heat a basement with a wall mount, keep in mind that a well insulated basements have very little loss, you are looking at 3000 to 6000 BTU heat load. Don't be temped to oversize the unit based on ton/sqft rules of thumb.
In most cases the wall mount will not help with dehumidification as there is very little cooling load even in hot summers, you can try it and see if you can get by with the dry mode some that some units have before going for a stand alone dehumidifer.