Air source heat pump efficiency is shaped by flow temperature, emitter sizing, defrost behaviour, controls, and how honestly the heat loss has been assessed. The numbers only mean something if the inputs are real.
The biggest efficiency mistakes are usually made before install day: optimistic assumptions, weak emitter checks, and a system route that does not really fit the property. · 3 min read
Use this guide as a decision check, not as a generic reading page. The useful question is whether the evidence behind air source heat pump efficiency in the real world is strong enough for an installer, designer, or homeowner to move to the next step without another round of avoidable questions.
For heat pump evidence, the weak point is usually not the headline requirement. It is the missing photo, document, measurement, or site note that stops the next person from trusting the job record.
A survey report should show what was seen, what was measured, what could not be accessed, and what still needs a design or installer decision. That keeps assumptions visible instead of hiding them inside a photo set.
The office, design, and install teams should be able to open the same report and understand the evidence path. If the page helps you spot what to ask for before survey day, it has done its job.
For a live project, pair this guidance with the sample report, deliverables, and guide price builder so the job is reviewed against the same standard Vertex uses for survey delivery.