Compare air conditioning quotes only after making their scopes equivalent. Each proposal should identify models and capacities, pipe and drain routes, outdoor-unit location, electrics, access, VAT, commissioning, warranty and exclusions. Verify required F-gas credentials and ask how the system was sized. The lowest total can be poor value if it omits electrical work, access equipment, condensate management or making good, while the highest price is not proof of better design.
Give each contractor the same brief
Describe the rooms, comfort problems, expected hours, heating requirement, noise concerns and appearance constraints. Tell contractors about leasehold, listed status, conservation areas and known electrical limitations.
Ask each bidder to survey the same preferred and alternative locations. If one quote assumes a roof condenser and another assumes a ground-level unit, their prices and risks are not comparable.
Check the technical proposal
The quote should state manufacturer, full model references, nominal and design capacity, indoor sound data and relevant efficiency figures. Ask for the reasoning behind capacity selection rather than accepting a rule based only on floor area.
Confirm the pipe route, included length, trunking finish, drain method and outdoor mounting. Identify condensate pumps, long lifts and inaccessible joints that may create future maintenance needs.
- Exact indoor and outdoor models.
- Room-by-room design loads or sizing rationale.
- Electrical circuit and isolator responsibility.
- Noise and anti-vibration provisions.
- Commissioning records and handover documents.
Compare commercial terms
Require a VAT-inclusive total and a schedule of optional or provisional charges. Check deposit, stage payments, cancellation terms, lead time, expected duration and responsibility for parking, scaffolding and permits.
Separate the manufacturer's parts warranty from labour cover. Ask who registers the equipment, what maintenance is required to keep cover valid, response arrangements for faults and whether travel or diagnostic charges apply.
Verify competence and permissions
Check the certified company responsible for regulated F-gas work and the qualifications of individuals performing it. Also clarify electrical competence, public liability insurance and any subcontracting.
No installer quote can remove the owner's responsibility to secure necessary planning, freeholder or listed building consents. A good proposal should identify obvious issues and state who will prepare supporting technical information, without pretending to make the authority's decision.
Make a balanced decision
Score proposals for design clarity, complete scope, likely disruption, serviceability, noise, running efficiency, warranty support and price. Ask written questions where differences remain.
Be cautious about pressure selling, cash-only demands, unexplained model substitutions and large upfront payments. Keep the accepted quotation, drawings, certificates, commissioning data and payment records together.
Frequently asked questions
How many air conditioning quotes should I obtain?
Three comparable proposals are often enough to expose major differences, but quality matters more than count. Use the same brief and ask bidders to explain conflicting recommendations.
Should I choose the cheapest quote?
Only if it provides the right design and complete scope. Add omitted electrics, access, drainage, VAT and making good before comparing totals.
What deposit is reasonable?
There is no universal percentage. It should be proportionate to equipment ordered and project risk, documented in the contract and paid through a traceable method.
Can an installer guarantee planning permission?
No. The local planning authority decides applications and lawful development questions. An installer can supply drawings, specifications and noise data.
What documents should I receive after installation?
Request the final invoice, model and serial details, commissioning record, controls instructions, warranty registration, refrigerant records where applicable and electrical certification for relevant work.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.