Written for HVAC professionals, consultants, commercial heating engineers, contractors, manufacturers, commissioning engineers and technically minded clients, the book examines why heat pump systems often underperform once installed.

Rather than blaming the heat pump itself, the book focuses on the system conditions around the machine. It argues that many poor outcomes are caused by design and application issues, including excessive flow temperatures, weak hydraulic design, poor emitter matching, incorrect buffer application, poor controls, domestic hot water behaviour, cycling, defrost and commissioning assumptions.

Craig Moreton said: “I’m yet to see a heat pump perform badly in the correct conditions. The problem is that too many systems are never properly designed, controlled or commissioned to create those conditions in the first place.”

The book challenges what Moreton describes as the “boiler mindset” — where heat pumps are sometimes approached using assumptions developed around high-temperature boiler systems.

It explains why heat pump performance is conditional, why a single COP figure does not represent real operation, and why consultants, contractors and designers need to consider the actual load profile, ambient conditions, flow temperature, return temperature, emitters, system volume, hydraulic separation, control strategy, part-load behaviour and defrost requirements.

For commercial HVAC readers, the book also explores plantroom behaviour, multi-unit staging, heat recovery, buffer vessel performance, weather compensation and how control strategy can either stabilise or destabilise a heat pump system.

The book is intended to help the HVAC industry move beyond simple heat pump selection and towards better system thinking.

Moreton added: “Heat pump design is not one size fits all. The aim of the book is to make people question the design properly before the performance problem appears.”

Why Heat Pumps Fail is available now on Amazon.