Ventilating an indoor pool
I have a client that has an indoor “infinity pool”. He refused to have the builder of the addition that houses the pool instal a ” just a fan” to ventilate the room. So….the room is now 5-7 years down the road and suffering from the indoor humidity, The walls are insulated with poly iso, and as far as I can tell just sheetrock or maybe skim coat. The windows seals are starting to go and the wood inside is looking shabby. We actually just re-flashed all the window on the outside as they we never taped to the Tyvek ( it wasn’t taped either) and the builder actually had the head flashing going behind the Tyvek. Nice couple of days work for my crew!
So, I’m confused as what to suggest for ventilation, HRV or ERV or other. I know he has baseboard heat, not sure if there’s AC in that room. The windows should open if there not to damaged from the humidity. He uses the pool year round so I assume it’s AC’d in the summer and there’s heat in the winter. My main goal is to get rid of the humidly and keep the heat or cooling inside the pool room. If i propose an elaborate system he’ll probably shoot it down ( but i might anyway)
Do you have suggestions as what to suggest?
Thanks
Steve Greenberg
Steveworks
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Step one is to cover the pool whenever it's not in use. If the original build was not done so as to be highly resistant to condensation, you're probably fighting an uphill battle.
He may be doing that, I'll have to go over and check how he "uses" the room.
To actually do it right, you can't use conventional building techniques, and it's extremely expensive in first cost and ongoing energy costs:
http://www.buildingscience.com/documents/insights/bsi-055-in-the-deep-end/?searchterm=swimming%20pool
Keeping the pool cover on 99.5% of the time and opening windows during use is the only cheap way out. And the pool cover has to fit perfectly. Be very careful what you promise.
Steve,
There are lots of opportunities to make mistakes. There may already be hidden damage inside the walls or ceiling. Tread lightly or tiptoe away.
By the way, window head flashing is supposed to go behind the Tyvek.
ERV/HRV cores may not hold up too well in high chlorine/bromine atmospheres. Active high-cfm exhaust only ventilation under dehumidistat control and keeping the pool covered when not in use is probably cheapest way out. If the use duty cycle is high, it really needs to be built like a pool building- very tolerant of high humidity, and not like a house.
Thanks for all the help. I'm starting to think that I'm going to take Martin's advice and tip toe away and not own any of the hidden issues.
Martin,
This is probably not the correct area for this but just want to make sure I'm doing this correctly. Actually it wasn't a window it was flashing that came of the roof where the slope ended and a side wall of the floor below extended . The flashing continued down the side of the lower floor under the Tyvek, The wall behind the Tyvek was soaked and rotted. We actually had to peel the old plywood off the foam behind it.
As to the window, you're right not sure what I was thinking when typing. I've done that detail many times ( by following many of the detail drawings on this site and the hundreds of demos I've seen at JLC)