The survey is the easy part.
The eleven months after it aren't.

The compressor manufacturer

Surveys as part of equipment and service sales, sometimes at no charge. Genuinely useful and the cheapest way to find out whether you have a problem at all — just know that the survey sits inside a commercial relationship with the equipment.

The independent inspection firm

Sells the survey itself and issues a standalone report. This is what you want when the finding has to hold up on its own — for an energy file, a budget request, or an argument about who pays for the loss.

The energy auditor

Looks past leaks at the whole system: pressure, flow, power draw, compressor sizing and control strategy. Slower and broader. The right call when you suspect the problem is the system design, not the pipework.

The recurring route

Repeats a fixed inspection route on a schedule rather than visiting once. The individual finding is no better — what changes is that this month's number can be compared with last month's, because the route and the sensitivity were the same.

Which to start with

If you have never measured at all, any competent baseline survey is worth more than choosing perfectly. Start, get a number, then decide how closely it needs watching.

What none of them change

The physics. Ultrasonic and acoustic-imaging detection is mature and works well. Nobody in this market wins on hearing the leak better — they differ on what you get afterwards.

The interval is the blind spot

The standard recommendation across the industry is one survey a year, two for heavy users. Leaks do not appear on that schedule. A fitting that starts weeping in October is paid for around the clock until somebody comes back in June.

A snapshot is not a trend

Each visit is a different technician, a slightly different route, a slightly different threshold. You get a number, but you cannot honestly compare this year's to last year's — so you never learn whether your maintenance is winning or losing.

What repetition changes

Not the physics — the comparability. The same route at the same sensitivity, logged every month, turns leak count and estimated loss into a line your energy manager can defend, instead of an annual surprise.

1 · Is every leak costed?

A list of leak locations is far less useful than a list ranked by AED per year. Ask to see a sample page before you commit.

2 · What happens between visits?

Ask what you get for the eleven months after the report. If the answer is nothing, price that gap into the decision — it is usually larger than the survey fee.

3 · Will the report stand up?

If the finding must support an ISO 50001 file, an energy claim or a dispute, ask how the report is signed and whether it can be verified later by someone who was not there.

4 · Who is the report for?

A survey attached to equipment sales is a legitimate service — just know its purpose includes selling equipment. An independent report is bought when the finding must stand alone.

5 · Does production stop?

It should not. Leaks are audible precisely when the system is under normal pressure, so any competent provider scans a running plant.

When a survey won't help

If your compressor is badly sized or your control strategy is wrong, fixing leaks will not save what you hope. Ask for pressure and flow to be looked at too, or you will fix the symptom.

Air-Leak Audit

Full acoustic-imaging sweep, every leak mapped on your plan and costed per year, delivered after one site visit. Report hash-sealed for the audit trail.

AED 9,500 · per audit, fixed

Factory Auditor plan

Ultrasonic leak mapping plus gauge reading on a monthly schedule — the same route each time, so the numbers stay comparable.

AED 6,900 · per month, from

HVAC & Refrigerant Check

Thermal and gas inspection of chillers, cold rooms and HVAC plant — documented before they become downtime.

AED 4,500 · per visit