Air to air heat pumps still live or die on good site evidence. The layout, electrical context, unit positions, and route notes need to be obvious before the office quotes confidently.
Related: air source heat pump survey overview · ASHP survey packs · ASHP survey checklist
Searchers often group air to air heat pumps and air source heat pumps together. On site, the evidence overlaps, but the decision points are not identical.
Air to air heat pumps move heat into indoor fan units rather than through a wet emitter circuit. That means no radiator sizing pack and usually no hot water cylinder evidence for the core heating scope.
The outdoor unit, access, sound, and electrical checks still matter, but indoor head locations, pipe and cable routes, condensate handling, and room-by-room placement decisions become more visible on the survey.
Air to air heat pumps can be sold quickly and then slow down later if indoor unit positions, cable routes, or electrical assumptions were never captured properly on day one.
Use the overview page when you want the plain-English explanation of what the survey covers before quote, design, and install.
Use the ASHP page when you want the pack output, handoff structure, and installer-ready deliverables rather than the broader search topic.
Use the checklist if the team needs a fast reminder of what should be photographed, measured, and labelled before the job leaves site.