Question #$4$

The two$-$story detached house shown in the figure provided is exposed to $6\frac{m}{s}$ wind, when the outdoor temperature and relative humidity are $-20C$ and $100\%,$ respectively. The indoor temperature and relative humidity are $21C$ and $30\%,$ respectively. Assume the density of air is $1\mathrm{.}2k\frac{g}{m^3}$ throughout.

a$)$ Calculate and draw the wind and stack$-$driven pressure difference profiles for all four exterior walls $($individually and their combined effect$).$ Assume that the drag coefficients $(C_D)$ are $0\mathrm{.}7$ and $0\mathrm{.}3$ on the windward and leeward walls, respectively. Neglect the wind$-$driven pressures on the walls parallel to the wind direction. Neglect the infiltration through the roof.

b$)$ Calculate the infiltration rate if the fan pressurization test results provide a flow coefficient $c$ of $0\mathrm{.}16$ and flow exponent $n$ of $0\mathrm{.}66.$ Recall that fan pressurization test provides air$-$leakage normalized with the exterior above$-$grade surface area: $q(\frac{L}{s}*m^2)=c*P^n.$ Assume that the neutral pressure plane exists at half the building height above ground level when there is no wind.

c$)$ Estimate the load due to air infiltration so that the indoor temperature and relative humidity can be maintained at $21C$ and $30\%,$ respectively.

d$)$ If a bathroom fan that exhausts air at a rate of $52\frac{L}{s}$ is turned on at these conditions, determine the load due to the infiltration driven by the bathroom fan.

e$)$ Assuming $$\frac{0\mathrm{.}10}{k}Wh$ to condition the building, estimate the hourly cost of infiltration calculated in $($c$)$ and $($d$)$ and compare their significance to one another.