Mold

[DHC]

I have a customer that has a under-ground tunnel from her main house to a 5 car garage with additional living space above the garage.

The tunnel is about 70'long and 8' wide.

It has a 90% furnace which heats the tunnel and the garage in the winter.

The obvious problem is mold, when we get heavy rains some water does get through the walls which goes to a drain in the floor but the humidity level is always around 80%.

The customer is going to have all the cracks sealed and the walls re-painted with the special paint that seals water out.

I put 2 portable dehumidifiers in the tunnel and at the end closest to the house I can get the %RH to 45% at the other end it will run non-stop and barely achieve 60%.

I was considering running a return into the tunnel adding a HRV and a UV light to the existing furnace, hoping this would solve the problems in the most cost effective manner.

IAQ is not my forte, I would appreciate any suggestions.

Thanks,
DHC

[ron thaman]

DHC, Anytime there is a below ground "room", relative humidity will always be a concern. Any measures (dehumidifuers, air circulation, etc) that reduces the %RH below 60% (ASHRAE standard)will keep the mold problem at bay.

[teddy bear]

Sounds like you need a "real " dehumidifier that will remove 70-80 pints of water a day. Check out the Santa Fe at thermastor.com. It's a 100 pint unit using 6.8 amps, operates down to 55^F. Thats about the same as a 40 pint residential unit. In green grass climates, adding ventilation will add to the humidity problem because of outdoor high dew points.

[in house worker]

clean the area with bleach and water use a respreater and heat it at 80 degrees for a week Then primer and paint it that should help the dampness problem.

[teddy bear]

The dampness is mostly a result of infiltrating damp air from outside. The amount of moisture passing through the tunnel materials is minor.

[DHC]

Thanks for the replies guys!

DHC

[grasshopper]

I have had great success in areas such as you describe by doing a clean-up and putting in a real good dehumidifier. I like the Santa-Fe's and have been checking out the new April-Air dehumidifier. They are more quite, more eff and perform better then the typical store bought portables.

[teddy bear]

Originally posted by grasshopper
I have had great success in areas such as you describe by doing a clean-up and putting in a real good dehumidifier. I like the Santa-Fe's and have been checking out the new April-Air dehumidifier. They are more quite, more eff and perform better then the typical store bought portables.

I got to check out a Aprilaire, 90 pints per day using 9.3 amps, a good looking unit. The Santa Fe provides 100 pints 6.8 amps. When you consider the heat load, the Santa Fe is 50% more effecient.

[grasshopper]

Originally posted by teddy bear

Originally posted by grasshopper
I have had great success in areas such as you describe by doing a clean-up and putting in a real good dehumidifier. I like the Santa-Fe's and have been checking out the new April-Air dehumidifier. They are more quite, more eff and perform better then the typical store bought portables.

I got to check out a Aprilaire, 90 pints per day using 9.3 amps, a good looking unit. The Santa Fe provides 100 pints 6.8 amps. When you consider the heat load, the Santa Fe is 50% more effecient.

Oh I agree it is a better product. Especially in this case. But the April Air is cheaper and more readily available for others/contractors in certain parts of the country, so it will be out there something fierce soon. It is still a major step up from most store bought portables.