Sensible Heat Flow
Sensible Heat Flow - SI-Units
The sensible heat flow can be expressed in SI-units (metric) as
Qs = cp ρ q Δt / 3600 (1)
where
Qs = sensible heat flow (kW)
cp = 1.005* - specific heat air (kJ/kg K)
ρ = 1.202* - air density at standard conditions (kg/m3)
q = air flow (m3/hr)
Δt = temperature (oC)
* Note that air properties changes with temperature. Interpolate values if necessary.
Sensible Heat Flow - English (Imperial) units
In English (imperial) units the sensible flow heat can be expressed as
Qs= 60 cp ρ q Δt
= 1.075 q Δt (2)
where
Qs = sensible heat flow (Btu/hr)
cp = 0.2388 - specific heat (Btu/lboF)
ρ = 0.075 - air density at standard conditions (lb/ft3)
q = air flow in (ft3/min)
Δt = temperature difference (oF)
Example - Sensible Heat Flow
10000 m3/h of air is transported through a building with the ventilation system. The temperature of the make up air is 0 oC. The temperature of the room air is 20 oC.
The sensible heat flow can be calculated as
Ql = (1.005 kJ/kg) (1.202 kg/m3) (10000 m3/h) ((20 oC) - (0 oC)) / 3600
= 67 kW
Related Topics
• Air Psychrometrics
Moist and humid air calculations. Psychrometric charts and Mollier diagrams. Air-condition systems temperatures, absolute and relative humidities and moisture content in air.
Related Documents
Cooling and Heating Equations
Latent and sensible cooling and heating equations - imperial units.
Cooling Load - Latent and Sensible Heat
Latent and sensible cooling loads to consider when designing HVAC systems.
Great Sensible Heat Factor - GSHF
The Great Sensible Heat Factor is the ratio sensible to total heat in a cooling coil.
Latent Heat Flow
Latent heat is the heat when supplied to or removed from air results in a change in moisture content - the temperature of the air is not changed.
Room Sensible Heat Factor - RSHF
Room Sensible Heat Factor - RSHF - is defined as the sensible heat load divided by the total heat load in a room
Sensible Heat Ratio - SHR
The ratio Sensible Heat (or Cooling) Load to the Total Heat (or Cooling) Load.