U Values

Question 1

Heat transfer rate equation

Answer 1

Q = U x A x T delta
Q = Heat transfer coefficient x area x temperature delta

Question 2

R value equation for solid materials

Answer 2

R = L / k
R = Thickness / thermal conductivity

Question 3

R value equation for air

Answer 3

R = 1 / heat transfer coefficient

Question 4

convective heat transfer equation

Answer 4

Q = h x A x (T -T )
= heat transfer coefficient x area x (Temp surface x Temp Inside)

Question 5

air exchange/infiltration equation

Answer 5

Q = m(dot) x SHC X Tdelta
Q = Mass flow rat of air x Specific heat capacity x temp delta

Question 6

what’s the density of air

Answer 6

1.2 kg/m3

Question 7

how to change from volume per hour, to volume per second

Answer 7

divide by 3600

Question 8

convert volumetric flow to mass flow equation

Answer 8

m = ρ ⋅ V

Question 9

Radiation Heat Transfer equation

Answer 9

Q = ε ⋅ σ ⋅ A (T^4 - T^4)
Q = Emissivity x SB constant (Tsurface^4 - Troom^4)

Question 10

Stefan-Boltzmann constant

Answer 10

5.67 × 10^−8