Cooling/Heating Systems and Components

Applied thermal systems from the Thermal & Fluid Systems lens: heat exchangers, cooling towers, and refrigeration cycles and heat pumps.

What the problems look like

Performance and duty calculations — heat exchangers (LMTD, ε-NTU, effectiveness); cooling towers (range, approach, makeup); and refrigeration cycles / heat pumps (COP, the P–h diagram, refrigerant mass flow, condenser/evaporator duty). Calculation-based.

By exam day you should be able to —

• size/rate a heat exchanger with LMTD and ε-NTU and compute effectiveness;
• compute cooling-tower range, approach, and makeup;
• work a refrigeration cycle / heat pump — COP (cooling vs. heating), the P–h diagram, refrigerant mass flow, and condenser/evaporator duty.

Where people lose points

• LMTD vs. ε-NTU applicability (unknown outlet temps → NTU); counterflow vs. parallel-flow.
• LMTD correction factor F (< 1) for multipass/crossflow — using pure-counterflow LMTD on a 1-2 shell-and-tube overstates ΔT.
• ε-NTU with the wrong capacity rate (q = ε·C_min·ΔT).
• COP cooling vs. heating — heat-pump COP_heating = COP_cooling + 1.
• Condenser load = evaporator load + compressor work.
• Cooling-tower range vs. approach.

Have these at your fingertips

LMTD, ε-NTU, the COP relations, and the P–h diagram — plus where they sit in the Handbook.

Going deeper

• Heat exchangers — LMTD & ε-NTU
• Refrigeration cycle & COP

Part of the Thermal & Fluid Systems depth. Practice this area with exam-real problems — the tutor walks any one you miss. → Start your 7-day free trial — no card. Or take the free practice exam first.