Industrial heat pumps: COP, applications and limits

A heat pump does not create heat: it takes heat from a source — outdoor air, water, the ground, or heat rejected by a process — and moves it into the circuit to be heated. That is why it returns several times the electrical energy it consumes, which no resistance heater or boiler can do.

This makes it an attractive option for Moroccan industry and hospitality. It does not make it universal, and the gap between quoted and observed performance is worth understanding before signing.

Reading a COP correctly

The coefficient of performance is the ratio of heat delivered to electricity consumed. A COP of 4 means four kilowatt-hours of heat for one kilowatt-hour of electricity.

Two cautions apply.

First, a COP is always quoted for a pair of temperatures. Performance depends on the gap between the source and the required flow temperature. The wider the gap, the lower the COP. A COP quoted for 35 °C flow will not be achieved if the installation requires 60 °C.

Second, instantaneous COP is not annual efficiency. That is the SCOP, the seasonal coefficient, which accounts for load and temperature variation across a full season. It is the SCOP that determines the bill.

For Morocco there is a practical consequence: winter outdoor temperatures being moderate on the coast, the real-world performance of an air source heat pump there is better than in European reference climates. Conversely, in cooling mode during a southern summer, outdoor heat degrades efficiency.

Applications that work well

Domestic hot water

This is the most profitable use. A hotel, clinic, boarding school or industrial changing block consumes hot water all year, with steady and predictable demand. The heat pump handles preheating up to an intermediate temperature, with a top-up stage covering the remainder and the thermal treatment required to control sanitary risk.

Swimming pools

Pool water is held between 26 °C and 29 °C. The gap from the source is small, so the COP is high. This is the textbook heat pump case, with short payback periods in hotel use.

Heat recovery from refrigeration plant

This is the most underused application. A refrigeration system continuously rejects heat at the condenser. Recovering it to preheat water or a space, instead of dumping it into the air, means obtaining that heat for the cost of a heat exchanger and a circulating pump alone. Any site with both a cooling requirement and a hot water requirement should examine this first.

Reversible commercial systems

One machine heats in winter and cools in summer, avoiding a second network and a second maintenance contract.

The limits

High temperatures. Above 70 to 80 °C the available range narrows and performance falls. A process requiring steam is not a heat pump application.

Highly intermittent demand. A heat pump is an investment whose value comes from running hours. A requirement of a few weeks a year does not repay it.

Existing emitters. Replacing a boiler with a heat pump without reviewing emitters designed for very hot water leads to disappointment: the heat pump will have to produce at high temperature, precisely where its efficiency is lowest.

Electrical sizing. Starting current and contracted supply capacity must be checked before installation, or the connection becomes an unplanned cost.

The payback calculation

It rests on four inputs: annual heat demand in kilowatt-hours, the SCOP expected under the site's real conditions, the electricity price actually paid — including time-of-use tariffs — and the cost of the current solution, based on its real rather than nominal efficiency.

Maintenance must appear on both sides of the comparison. A heat pump requires refrigerant circuit servicing and leak testing that a boiler does not; conversely, it removes the constraints of combustion and fuel storage.

What to verify before signing

• Are COP and SCOP quoted at the temperatures your installation actually requires, rather than at catalogue conditions?
• Has the emitter temperature regime been verified, or merely assumed?
• Is there recoverable waste heat on site to consider before an air source machine?
• Is energy metering included? Without a meter, real performance will never be known and the commercial promise stays unverifiable.

That last point is the best indicator of a serious offer. An installer confident in the sizing offers to measure it.