Heating Losses- Infiltration and Ventilation. ARCH-432. Attendance. Which civilization made it a point to layout whole cities to take advantage of passive heating? In what direction did the city streets run? Greece Rome Egypt Persia Babylonia. Attendance.
The ancient Greeks did this. What was shown is Priene (Priēnē); (5th Century B.C.), which had all of the streets laid out in an East-West fashion, thus allowing all homes to point South.
“Only primitives and barbarians lacked
knowledge of houses turned to face the
winter sun, dwelling beneath the ground like swarming ants in sunless caves.”
Aeschylus pronounced Ess ca less
One of the earliest writer of Greek tragedy – before him plays had single actors who could only respond to a chorus (group of people). Aeschylus increase the tragedy to two actors with dialog.
Infiltration and Ventilation
Five main types of heat loss
1. Transmission (conduction)
2. Infiltration (convection)
3. Ventilation (convection)
4. Radiation (radiation)
5. Moisture migration
“The uncontrolled introduction of outside air into a building.”
The uncontrolled introduction of fresh air into a building.
1. Most subjective of all losses
2. Oftentimes the largest of all heat losses.
Sometimes comprises up to 30% of the total
3. Ends up being an “educated guess”
CFM = Ft. of Crack x Infiltration Rate
QS = 1.1 x CFM x (T2 – T1) in BTU/HR
CFM = ת x D
LEED-NC Credit EQ 5 for providing vestibules.
QS = 1.1 x CFM x (T2 – T1)
QS = 1.1 x (CFH/ft of crack x ft of crack)/60 x ΔT
You own the variables!
CFM = A.C.H. x Volume (ft3)/60
CFM = Volume (ft3)/Frequency (minutes)
Btu H = (.018) x (ACH) x V x (Ti – To)
ACH = air exchanges per hour
V = volume
Ti = inside temperature
To = outside temperature
Btu H = 1.1 x CFM x (Ti – To)
CFM = (ACH x volume) / 60 min per hour
For tight construction use 0.5 for ACH.
For medium construction use .85 for ACH.
For loose construction use 1.3 for ACH.
For really bad construction use 2.0 for ACH
For the summer months (cooling) use 70% of the winter values.
BtuH = 4500 x (air exchanges x (volume) /60) x
(W Final – W Initial)
(W Final – W Initial) = Difference Ratio Pounds of Moisture per dry air
Btu H = 1.1 x [(Ra x square feet of building ) +
(number of people in the building x Rp )]
(Ti – To)
Ra = Area Outdoor Air Rate
Rp = People Outdoor Air Rate
Ra = .18
Rp = 5
Btu H = 1.1 x [ (.18 x 3,632) + (30 x 5)] x 76o
and / or