Air Conditioning Repair Certification (ETI) Practice Exam

To determine the water leaving temperature, we need to consider the amount of heat absorbed by the water as it cools the refrigerant in the condenser.

First, we know that 10 pounds of refrigerant are passing through the condenser and losing 20 BTUs per pound. This means the total heat lost by the refrigerant can be calculated as follows:

Total heat lost = (weight of refrigerant) × (BTUs lost per pound)

Total heat lost = 10 lbs × 20 BTUs/lb = 200 BTUs

This heat loss is absorbed by the water flowing through the condenser, causing it to warm up. If the water enters the condenser at 80 degrees Fahrenheit, we can find the leaving water temperature by adding the temperature rise to the inlet temperature.

We need to know how much temperature change corresponds to the 200 BTUs absorbed by the water. Assuming the water itself has a specific heat capacity of approximately 1 BTU/lb°F (a standard assumption for water), we can relate the increase in temperature to the amount of heat absorbed by using the formula:

Temperature Change (ΔT) = Total Heat Absorbed / (Weight of Water × Specific Heat Capacity)

Although the weight of water