Wet Floors

[hhac]

Heres what we have. I am sure alot of you heard of 5 Guys Famous Hamburgers & Fries, well here is the dilema. I took over this account from the a/c contractor that installed it because the owner wasn't happy with there service. (It helped the store manager knows me too) but any way I was called out because the building wasn't cooling well and there was a constant screeching sound no one could find. When I arrived I found the belts and pulleys way out of alignment and pulleys on motors were opened to wide for the belt. Got all that taken care of and got a call the next day. I was told the a/c is working great now and are quiet as can be, but the diffusers were dripping water from them now. Went back out and took a real good look at the system's. Found the fresh air vents were completely closed off and that one of the 3 units was grossly overcharged with refrigerant. (the old a/c company did replace the evap coil in it). Now we have a new dilema. The floors in the building seem to be wet all the time now, like dew on your windshield in the morning. It has been suggested it may have to do with the fresh air intake over the grills or there is a water leak under the slab and its pulling moisture up from that. I have worked with many kitchens and never had seen this type of problem, at this point I am at a loss does anyone have any suggestions what I may be over looking.:confused:

[ON-CALL]

Wet walls,windows,and grills but just the floors now I think the mang. likes you.But their are water leak dection companys.

[frank slusher]

sounds like there is too much cooling and no dehumidification. Also check the make up air hood. If you are bringing in too much outside air and not exhuasting, the humity will hang in the cool area. We have had a similar problem in an arena, they over cooled the space and had outside air dropping in from the ceiling 75' up, we had ice on the floor for a later show and every surface in the building was wet.
Check to see if the units are staging correctly, is the new coil 1st stage on top or bottom? Could be that 2nd stge is running while 1st stage is not. The fact that diffusers were wet is indicating very high humidity or low discharge air temp.

[ON-CALL]

frank what your saying you feel clamy but I think just the floor and nothing is wet

[frank slusher]

Hey you may be right, we had a room and hallway in the arena that was always hot. Guys were complaining that the A/c would not keep up. Noticed a hissing noise under the floor and was told not to bother, had been that way for years. Room got hotter and then we found water leaking out of the wall below a few hundred feet away. We dug up the floor and found a 1" hole in a 1.5" 90, 125 psi wp, and on the hot water loop. Floor was always dry though, it was a foot thick. The a/c works great now at amedium setting.

[ACking]

increasing air speed across a coil decreases the removal of moisture.

[buddylee]

Are they shutting down the air at night and leaving the make up air in the kitchen running, had a huge problem with that at a local restaurant. Took engineer 2 months to figure out why the ceiling tiles were dripping. But they don't want to listen to a tech when they have a degree.

[jogas]

Things I'd try:
1. Pick an out of the way floor test section, dry it and tape down a 1 square
foot of clear plastic with it's perimeter sealed. Protect and check it in 2-7
days. Moisture buildup below plastic means it's coming up through the floor.
2. Make sure they don't hose down the floor when doing cleaning.
3. Place a 7 day recording (chart) hygrometer in the space to document
actual humidity.
4. What is the evaporator temperature and temperature drop thru the wet
floor unit(s).
The results should send you in the right direction.
Good luck,
jogas

[hvacker]

If the moisture is all over it sounds like the floor is cold enough to condense moisture in the air.

Too much fan speed warming the evap coil and not removing enough moisture

Too much outside air being introduced causing warming of the coil and not reaching the dew point.

The makeup air for the stoves supplies more than the stove exhaust air introducing OSA that is laden with humidity.
Just some thoughts.
I would tale a psychrometer and measure the humidity. That will give you an idea what wet bulb temp you'll need to dry the air out if that's the problem.

Most floors that contact the ground w/o insulation will be close to that of the ground temp which can be 53-58 deg. Because of the temp gradient they won't feel that cold.