Drying time after wash down
Drying time after wash down
(OP)
Need help on 2 things:
1 - Best (cost & time) method to dry out a room after it has been thru a washdown process?
2 - How long until room is relatively dry & at design conditions?
Some additional background. Room (40Lx40Wx20H) will be washed down once everyday. Owner would like to have room turned over in 3 hours. The 3 hrs is from time process is shut down until room is back at design conditions (76F DB/60% RH). Room will be sprayed down at 100F. Initial design includes VAV RTU with gas heat, DX coil & terminal reheat coils. RTU to serve multiple rooms with similar processes.
My initial thought is to exhaust the room 100% at 10 ACH with elevated temps (90F/40% RH) for 1-2 hrs. Remaining time would be at 5 ACH @ 60-65F supply air to bring room down to 76F/60% RH.
TIA
1 - Best (cost & time) method to dry out a room after it has been thru a washdown process?
2 - How long until room is relatively dry & at design conditions?
Some additional background. Room (40Lx40Wx20H) will be washed down once everyday. Owner would like to have room turned over in 3 hours. The 3 hrs is from time process is shut down until room is back at design conditions (76F DB/60% RH). Room will be sprayed down at 100F. Initial design includes VAV RTU with gas heat, DX coil & terminal reheat coils. RTU to serve multiple rooms with similar processes.
My initial thought is to exhaust the room 100% at 10 ACH with elevated temps (90F/40% RH) for 1-2 hrs. Remaining time would be at 5 ACH @ 60-65F supply air to bring room down to 76F/60% RH.
TIA





RE: Drying time after wash down
How dry is "relatively dry"? Are you interested in only air humidity, or surfaces also? What are the surfaces?
RE: Drying time after wash down
Equipment is stainless steel & floor is an epoxy finish. Elevated temps would be around 90F/35% RH.
RE: Drying time after wash down
RE: Drying time after wash down
How much "equipment" is there? What's the total surface area of those equipment?
How did you determine your ACH? I'm swagging about 46kg of water on the walls and floor/ceiling, and swagging 10% effectivity in each ACH's ability to grab water, given the relatively low 90F temperature, which results in about 38kg of water removed in 2hr. Obviously, my effectivity is a total guess, and if it's higher then there may be sufficient margin.
Starting with 40%RH is not helping. And you only have 6 min to evaporate ~6.5kg of water per air change.
TTFN

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RE: Drying time after wash down
Ideally, we would like to use a desiccant wheel, but budget won't allow. So, looks like we need to dry the supply air as much as possible & exhaust the vapor out.
RE: Drying time after wash down
RE: Drying time after wash down
Have you considered sending in someone right after washdown with an industrial strength leaf blower to blow standing water off the areas that pool?
Good luck,
Latexman
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