H.6 heating energy consumption of ventilation, H.5.4 heat energy losses through envelope, Where – Retrotec USACE User Manual
Page 365
Appendix H H5
Q
vent
= thermal load on ventilation, kWh
Q
hv
= thermal load on hot water supply, kWh
Q
int. load
= internal thermal emissions, solar radiation, and heat recovery from
exhausted air, kWh
=
effi ciency of heat generation
H.5.4 Heat Energy Losses through Envelope
Q
loss
=
∑
[k * A * 24 * S ] /1000
+
q
s
* A
where
Q
loss
= heat energy losses through the building envelope, kWh
k
= overall heat transfer coeffi cient of the envelope element, W/m
2
* °C
A
= area of the building element, m
2
24 =
coeffi cient converting degree days to degree hours, hr/day
S
= heating degree days, °C * days
1,000 = coeffi cient converting Wh to kWh
q
s
=
energy
fl ow density through elements of envelope adjacent to soil, kWh/m
2
H.6 Heating Energy Consumption of Ventilation
Q
vent
=
* C * q
v
*
* 24 * 24 * S * r * t
w
−
Q
HR
where
Q
vent
= heating energy consumption on ventilation, kWh
= air density, kg/m
3
C
p
= heat capacity of air, kJ/(kg * °C)
q
vent
= ventilation
airfl ow rate, m
3
/s
= operating time of ventilation system per day, h/24 hr/day
24 =
coeffi cient converting degree days to degree hours, hr/day
S
= heating degree days, °C * days
r =
coeffi cient taking into account the daily operation time of ventilation