Help with a HRV system in shop

[1hawkeye]

I posted this in the general forum and thought maybe someone here could help me out in more detail trying a HRV system........Looking for recommendations on brand, sizing, where to install, and how they are controlled.

I have a 45' x 64' pole building with 18' ceiling. The walls are sprayed with closed cell foam and the ceiling has blown in fiberglass insulation. I only have one end (45x32) of the floor poured. I have plastic down, then 2" of styro foam insulation with pex tubing under the 6" thick slab. The other end is still dirt. It is not taking much to keep it 50 degrees in the shop but my problem is moisture. It is always 70-80% humidity. I have condensation on my doors and windows. I am attributing it to the dirt floor. I live in central Iowa, so normally between 0 and 30 degrees F. in the winter. I am looking for ways to control the moisture until I can afford to put concrete in the whole thing. Thanks in advance.

 

[pseudorealityx]

Do you need to 'work' on the dirt area between now and when the concrete is finished?

Short answer is a HRV isn't likely to do much, because you have a huge source of moisture (ground). The ground is acting like a wet sponge. If it rains outside, that moisture seeps to the ground within your building and becomes moist. And because it's warm in there, it can easily evaporate into the air.

Best 'solution' would be to seal the dirt/ground area off with plastic until you can finish the floor.

 

[LS6 Tommy]

Mitsubisihi makes ERVs that can interface with their minispilt systems. I just installed one in one of our call centers. Almost dead silent, thr room maintains more steady temps and the people in the room say they feel more alert to boot.

Tommy

 

[dfiler2]

Keep in mind if this is a new building the moisture will be pretty high the first year.

 

[pseudorealityx]

Mitsubisihi makes ERVs that can interface with their minispilt systems. I just installed one in one of our call centers. Almost dead silent, thr room maintains more steady temps and the people in the room say they feel more alert to boot.

Tommy

Greenheck makes some small ones that I like. Also since you're in a colder climate, you need to pay attention to frost control.

 

[JACDes]

crack open some windows or lower the temp to 40-45.. until you need actually to be out there working.

because the doors and windows are less insulated than the spay foam walls you are getting condendsation on these surface as the heat flows thru them to the outside.

the floor not being completed is aggravating this problem.

 

[1hawkeye]

Do you need to 'work' on the dirt area between now and when the concrete is finished?

Short answer is a HRV isn't likely to do much, because you have a huge source of moisture (ground). The ground is acting like a wet sponge. If it rains outside, that moisture seeps to the ground within your building and becomes moist. And because it's warm in there, it can easily evaporate into the air.

Best 'solution' would be to seal the dirt/ground area off with plastic until you can finish the floor.

I do need to work in this area, I have tractors and some equipment parked there and also tools and supplies are in this area

Keep in mind if this is a new building the moisture will be pretty high the first year.

The building was put up over 2 yrs ago and half of the concrete right at 2 yrs ago

crack open some windows or lower the temp to 40-45.. until you need actually to be out there working.

because the doors and windows are less insulated than the spay foam walls you are getting condendsation on these surface as the heat flows thru them to the outside.

the floor not being completed is aggravating this problem.

I have a window cracked and have tried to keep it cooler, not a big difference. I am in there at least a little bit every day. I am thinking about putting down plastic with rock on top of that.

 

[dfiler2]

It seems odd to me that in a shop that size you would be having a moisture problem with only one person using it. I realize the spray foam has it sealed pretty tight so maybe it is the uncovered area. I would do a little test before going through the work of the poly and stone. Lay a 4' x 4' (or so) piece of clear poly on the ground and seal the edges by laying something on them. wait for 24 hrs or so and see if there is any condensation on the back of the poly. If the poly is dry I would look elsewhere for the problem.

 

[1hawkeye]

Lay a 4' x 4' (or so) piece of clear poly on the ground and seal the edges by laying something on them. wait for 24 hrs or so and see if there is any condensation on the back of the poly. If the poly is dry I would look elsewhere for the problem.

That is a good idea, thanks. While I am confident that is where the problem is, this is a easy way to confirm it. I don't know what else could be causing it.

 

[BadgerBoilerMN]

hawkeye has it. You have to put down poly and gravel if you want it to dry out. Warmer is dryer so turn it up.