Swimming pools
Evaporation in the swimming pools in normal activity in kg/h
m2
The rate of evaporation in kg/h m2 can be estimated for the swimming
pool in normal activity, integrating splashing due to the bathes
on the accesses of a limited zone (Smith, et al., 1993) (ASHRAE,
1995), according to the following formula:
 W = Rate of evaporation at the surface of the water level (kg/h
m2)
 Pw = Vapor pressure at saturation taken at the temperature of
surface of water, in kPa
 Pa = Vapor pressure at the dew point according to the temperature
of the ambient air of the room, in kPa
 V = Air velocity above at the surface of water, in m/s
 Y = Latent heat necessary according to the change of state of
the water vapor at the temperature of surface of water, in kJ/kg
Function = Pool_evap1(ts1, ts, Hr, Saw, Z)
 ts = Dry temperature in °C of the ambient air of the swimming
pool
 ts1 = Temperature in °C at the water level
 Hr = relative Humidity in %
 Vit = Air velocity in m/s at the level of water
 Z = Altitude in m
Evaporation in swimming polls in kg/h m2 according to the
type of activity in the covered swimming pools
For a latent heat (Y) of a value of 2330 kJ/kg and with a speed
of air (V) at 0,10 m/s and while multiplying by a factor of activity
(Fa) to reduce the rate of evaporation estimated according to the
corresponding level of activity, the equation is reduced to the
following expression:
 W = Rate of evaporation at the surface of the water level (kg/h
m2)
 Pw = Vapor pressure at saturation taken at the temperature of
surface of water, in kPa
 Pa = Vapor pressure at the dew point according to the temperature
of the ambient air of the room, in kPa
Type of swimming pools 
Factor of activity (Fa) 
Residential swimming pools 
0.5 
Condominium 
0.65 
Thermal baths 
0.65 
Hotel 
0.8 
Public swimming pools or Schools 
1 
Whirlpools, spas 
1.5 
Wave pools, water slides 
1.5 (minimum) 
Evaporation at the level of water in kg/h m2
 ts = Dry temperature in °C of the ambient air of the swimming
pool
 ts1 = Temperature in °C at the level of water
 Hr = Relative humidity in %
Function = Pool_evap2(ts1, ts, Hr)
Evaporation at the level of water in kg/h m2 (another formula)
Evaporation at the water level in kg/h m2
 W = Rate of evaporation at the surface of the water level (kg/h
m2)
 We = water content of the air at the temperature of the water
level (kg/kg of dry air)
 Wa = water content of the air of the room (kg/kg of dry air)
 V = Specific volume of the air in the room (m3/kg of dry air)
 Vµ = Specific volume of the air at the level of water
(m3/kg of dry air)
Function = Pool_evap(ts1, ts, Hr, Z)
 ts = Dry temperature in °C of the ambient air of the swimming
pool
 ts1 = Temperature in °C of the water level
 Hr = Relative humidity in %
 Z = Altitude in m
For this type of formula, it is necessary in theory to add projections
of water and the latent gains caused by the bathers
Sensible contributions by radiation
 T water = temperature of the water of the basin
 Ts = Ambient temperature of the swimming pool
Function = Pool_rayon(ts1, ts)
 ts = Dry temperature in °C of the ambient air of the swimming
pool
 ts1 = Temperature in °C of the water level
Sensible contributions by convection
T water = temperature of the water of the pool
Ts = Ambient temperature of the swimming pool.
software, softwares, program, computation,
calculation, equations, indoor, pool, air, relative, humidity, water,
vapor, steam, pressure, sensible, contributions, convection, swimming,
pool, reheating, tank, open, area, wet, bulb, temperature, dry,
bulb
Last update:
