In the condenser example, the BTU transferred by the water is

In the condenser example, the BTU transferred by the water is

• A. 100 BTU
• B. 300 BTU
• C. 200 BTU
• D. 400 BTU

Answer: (C)

In a condenser, the water picks up the heat rejected by the refrigerant. The amount of heat transferred to the water is set by how much water is moving (its mass flow) and how much its temperature rises. The relationship is Q̇ = ṁ × Cp × ΔT. For water, Cp is about 1 BTU/lb·°F and 1 gallon weighs roughly 8.34 lb, so the water’s heat-uptake rate is Q̇ ≈ GPM × 8.34 × ΔT (BTU/min). If the problem gives a water flow of 3 gallons per minute and a temperature rise of 8°F, then Q̇ ≈ 3 × 8.34 × 8 ≈ 200 BTU/min. That means the water is transferring about 200 BTU of heat per minute.

In a condenser, the water picks up the heat rejected by the refrigerant. The amount of heat transferred to the water is set by how much water is moving (its mass flow) and how much its temperature rises. The relationship is Q̇ = ṁ × Cp × ΔT.

For water, Cp is about 1 BTU/lb·°F and 1 gallon weighs roughly 8.34 lb, so the water’s heat-uptake rate is Q̇ ≈ GPM × 8.34 × ΔT (BTU/min). If the problem gives a water flow of 3 gallons per minute and a temperature rise of 8°F, then Q̇ ≈ 3 × 8.34 × 8 ≈ 200 BTU/min. That means the water is transferring about 200 BTU of heat per minute.