Retrotec USACE - Manual (Page 366)

H6 ENERGY & PROCESS ASSESSMENT PROTOCOL
t
w
= operation time of ventilation system/week, days/7 days
Q
HR
= utilized heating energy recovered from exhaust air by heat recovery
equipment, kW
H.7 Heating Energy Consumption due to Infi ltration
Q
inf
= ␳ * C
p
* n
inf
* V * 24 * S / 3600
where
Q
inf
= heating energy consumption due to infi ltration, kWh
␳ = air density, kg/m 3
C
p
= heat capacity of air, kJ/(kg * °C)
n
inf
= infi ltration airfl ow, air changes per hour, ACH or (m 3 /h)/m 3
V = building volume, m 3
24 = coeffi cient converting degree days to degree hours, hr/day
S = heating degree days, °C * days
3,600 = coeffi cient converting hr into sec
H.8 Cooling Energy Consumption
Q
cool
= 24 BLC * CDD / COP
where
Q
cool
= cooling energy consumption, kWh
24 = coeffi cient converting degree days into degree hours
BLC = building loss coeffi cient, W/°C
CDD = cooling degree days, °C * days
COP = coeffi cient of performance of air conditioner
The accuracy of a building energy balances depends on many factors, in-
cluding the accuracy of measuring devices, number of measurement points,
duration of measurements, and so on, but shall be better than 5–5%, depend-
ing on the size of the facility. When computing an energy balance, it is neces-
sary to pay attention to operating modes of systems and the process equip-