GRAND SENSIBLE HEAT FACTOR

It is defined as the ratio of total sensible heat to the grand total heat which the cooling coil or conditioning apparatus is required to handle (Fig. 20.31).

where TSH = total sensible heat = RSH + OASH

TLH = total latent heat = RLH + OALH

GTH = grand total heat = TSH + TLH = (RSH + OASH) + (RLH + OALH)

Let V̇₁ = volume rare of outside air m³/min

t_d1, t_d2 = DBT of outside and room air respectively, °C

w₁, w₂ = specific humidity of outside and room air respectively kg/kg.d.a

h₁, h₂ = enthalpy of outside and room air respectively, kJ/kg d.a

Outside air total heat, OATH = OASH + OALH

Figure 20.31 RSHF line estimation