Latent Heat gain for hot showers
Latent Heat gain for hot showers
(OP)
Greetings, I am designing an HVAC system for a shower/shave facility. I have determined all the heat loads but am so far stumped on how to determine heat gained from running the showers themselves. With no guidance I am looking at doing a direct vent from the shower area to the outside environment and adding a reheat to the HVAC unit. Does anyone have a good reference or equation to find the latent heat gain from the showers, 20 in total?
Many Thanks,
Many Thanks,





RE: Latent Heat gain for hot showers
RE: Latent Heat gain for hot showers
Pretending (for fun) that your shower room was actually a very shallow pool of hot water with a high activity factor (due to the mixing of the showers.)
Evaporation rate of a pool=
0.1 x Area x (Vw-Vp) * Activity Factor
I'm going to assume shower water temperature of 90F (Vw = 1.422). I'm going to assume we're controlling the temperature of the shower room to 78F and 60% RH (Vp = 0.58)
Based on the above I'd guesstimate the following:
0.1 x Area x (1.422-0.58) * 1.2
0.1010 x Area = Latent Load in lb/hr. Covert to BTU/hr based on ~1000 Btu/lb.
1010 (Btu/hr)/ft2 = Latent Load at peak.
Seems reasonable, in not a little high. If the shower room can get warmer, and more humid that load will drop quickly.
Genererally, as SAK9 has pointed out, we usually use mechanical ventilation at a fairly high rate to deal with shower rooms.
RE: Latent Heat gain for hot showers
Install your shower head into a closed and sealed (except for water drain) test cell.
Also in the cell: dehumidifier, temperature and humidity measurement sensors.
Determine the ABSOLUTE humidity of the air in the cell prior to starting.
Run the shower for some representative shower-taking time.
Run the dehumidifier until the absolute humidity returns to the initial condition.
Measure the mass of water collected by the dehumidifier. Given this mass of water, the shower water temperature and the desired space air conditions you can determine the latent load.
RE: Latent Heat gain for hot showers
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: Latent Heat gain for hot showers
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: Latent Heat gain for hot showers
RE: Latent Heat gain for hot showers
RE: Latent Heat gain for hot showers
Thanks again