$2.)$ A building has the following dimensions:

Floor and Roof $=150\text{'}-0"\backslash$times $100\text{'}-0"$

Number of Floors $=10$

Story Height $=12\text{'}-0"$

The walls have a combined $"R"$ value of $25,$ the roof $"R"$ is $30,$ and the loss through the slab$-$on$-$grade is $1\mathrm{.}5Bt\frac{u}{f}\frac{t^2}{h}r.$

The outside temperature is $30F,$ and it is desired to keep the interior temperature @ $75F.$ There are $1\mathrm{.}5$ air$-$changes per hour.

How much heat is lost in one hour?

If another layer of insulation with an $"R"$ of $10$ is added to the exterior walls, how many BTU$/$hr$.$ are saved?

$3.)$ The building described in question $2.)$ above has a Circulation Factor of $0\mathrm{.}85,$ If the maximum heat gain from ALL sources is $25$ BTU$/$hr$.$ per NET $f{t}^2$ :

Size the Chiller and Cooling Tower

If the Chilled Water Supply to the AHU's is $45F,$ and the Chilled Water Return from the AHU's is $55F$

Calculate the required water flow to and from the Chiller