The published technical information is shown below for TempStar air conditioners. Rating is provided for an outside air temperature of 95°F and an inside temperature of 80°F. For the model N4A318AKA: a.What is the COP [1.96] b.What is COP Carnot [36.0]

Given:

• The outside temperature is T_o=95^oF= (95^oF+460.67)=554.67 R.
• The inside temperature is T_i=80^oF=(80^oF+460.67)=539.67 R.

(a)

The COP of TempStar air conditioners for the model N4A318AKA can be calculated using the below relation:

$$\begin{gathered} \begin{array}{rcl}& & C\end{array}\begin{array}{rcl}& & O\end{array}\begin{array}{rcl}& & P\end{array}\begin{array}{rcl}& =& \frac{Q_o}{W_{in}} \end{array} \\ \begin{array}{rcl}& & C\end{array}\begin{array}{rcl}& & O\end{array}\begin{array}{rcl}& & P\end{array}\begin{array}{rcl}& =& \end{array}\begin{array}{rcl}& & \frac{Q_o}{VI}\end{array} \end{gathered}$$

Here, I  is min. circuit ampacity for model N4A318AKA and V is the voltage rating of the single-phase that is V=230 V (supplied to the house). The voltage range supplied to the house is of range 220 V-240 V. The average rms value is 230 V.

Substitute all the known values in the above expression.

$\begin{array}{rcl}COP& =& \frac{18000 {\displaystyle \raisebox{1ex}{$\text{btu}$}\!\left/ \!\raisebox{-1ex}{$\text{h}$}\right.}}{230\times 11.7}\\ COP& =& \frac{18000 {\displaystyle \raisebox{1ex}{$\text{btu}$}\!\left/ \!\raisebox{-1ex}{$\text{h}$}\right.}}{2691 \text{W}}\\ COP& =& \frac{18000 {\displaystyle \raisebox{1ex}{$\text{btu}$}\!\left/ \!\raisebox{-1ex}{$\text{h}$}\right.}}{2691 \text{W}{\displaystyle \frac{3.42 {\displaystyle \raisebox{1ex}{$\text{btu}$}\!\left/ \!\raisebox{-1ex}{$\text{h}$}\right.}}{1 \text{W}}}}\\ & \approx & 1.96\end{array}$

Thus, the COP of temp star air conditioners is 1.96.