Resource
25 Sep 2026
Planning a new or replacement office air conditioning installation involves more than comparing equipment and contractor quotes. The system will influence electricity use, operating costs, maintenance and future energy purchasing. The report delivered as part of a TM44 Air Conditioning Inspection can provide evidence for a more confident decision.
Our TM44 service assesses system efficiency, identifies faults and provides practical recommendations. Our value-added report projects energy consumption and operating costs at system and site level, identifies under-sized or oversized systems and sets out estimated costs, potential savings and return on investment.
In short: Use the TM44 report to establish how your existing system performs, decide what should be optimised or replaced, model the likely change in electricity consumption and update procurement requirements before committing to a new contract or installation.
A TM44 inspection is a legal requirement for building owners or managers responsible for air-conditioning systems with a combined effective rated output of 12kW or more. This can include several smaller units whose total output reaches the threshold. Inspections must be completed every five years and carried out by an accredited air-conditioning energy assessor.
Compliance is only the starting point. Our accredited assessors review refrigeration equipment, air and water movement systems, controls, faults and unnecessary energy use. The report can support maintenance, capital investment and long-term energy planning.
Replacing equipment without understanding poor performance can lead to unnecessary expenditure or a system that does not reflect how the building is used. TM44 findings provide evidence for discussing scope, capacity, controls and operating costs. Use that evidence to create a performance brief for the office air conditioning installation before tendering.
1. System sizing and actual cooling requirements
An oversized system can consume more electricity than necessary, while an under-sized system may struggle to meet demand. Our TM44 service evaluates system size, helping you challenge assumptions before specifying new equipment.
At Cheam Fields Primary Academy, Zenergi found that 10 of 11 units were oversized, with only one correctly sized. The report also identified practical control changes and quantified savings opportunities. Although every estate is different, the case study shows why historic capacity should not automatically become the replacement specification.
For an industrial air conditioning installation, review process loads, operating hours, occupancy patterns and critical cooling requirements alongside the TM44 findings. Industrial sites may have demand profiles that are not adequately represented by capacity alone.
2. Controls, schedules and operating behaviour
The equipment may not be the only source of waste. A TM44 inspection considers how controls are used in practice and can reveal incorrect settings, inefficient schedules and unnecessary operation.
Before approving a commercial air conditioner installation, establish whether control, maintenance or operational changes could address part of the problem. Our Building Optimisation Survey combines on-site expertise with granular consumption data, building management system insight and operational context. It can identify issues such as misaligned BMS and HVAC controls, out-of-hours use and overcooling.
3. Current consumption, cost and return on investment
The air conditioning unit installation price is only one part of the business case. Our value-added TM44 report projects consumption and operating costs and provides insight into implementation costs and potential savings. This supports a more consistent comparison of optimisation, repair, phased replacement and full replacement.
Build the investment case around whole-life value, including capital cost, forecast electricity use, expected maintenance, controls and the operational risk of retaining inefficient equipment. Ask suppliers to state the assumptions behind their projections so that competing options can be compared on the same basis.
A practical forecast can be built in four stages:
For a multi-site office air conditioning installation programme, complete this exercise per site before consolidating the expected annual change. Our Portal provides granular reporting on energy usage, costs, validation and budgeting as part of our Bill Validation service, helping organisations monitor consumption.
An installation can change both total electricity volume and when electricity is consumed. That makes the forecast relevant to the next procurement cycle. Our Energy Procurement service assesses suppliers, contract durations and fixed, flexible and green options against consumption, budget requirements, risk tolerance and sustainability objectives.
Before tendering or renewing an energy contract, give the procurement team a dated forecast showing the baseline, installation dates, expected savings and a reasonable uncertainty range. This reduces the risk of basing contract requirements on a demand profile that major works are about to change.
For a phased industrial air conditioning installation, map each commissioning date against the relevant procurement period. For several offices, consolidate forecasts and consider aligning contract end dates. Zenergi can present like-for-like supplier comparisons and risk information, while its our market insight supports decisions about contract type and duration. The office air conditioning installation forecast then becomes an input to procurement rather than a separate technical document.
The lowest air conditioning unit installation price may not deliver the lowest overall cost. A stronger appraisal considers:
Our Mechanical and Electrical Design service integrates energy-saving measures into building design and can support projects from feasibility through design, completion and post-completion. This creates a route from compliance insight to a technically considered project rather than treating the installation as an isolated purchase.
It can provide much of the evidence needed. Our report identifies faults, inefficient systems, sizing issues, implementation costs, potential savings and projected return on investment. The final investment decision should also reflect building requirements, asset condition, available budget and project priorities.
Review them before defining the project scope, again when comparing proposals and after commissioning when actual consumption can be checked against the forecast. This keeps the compliance findings connected to design, procurement and ongoing energy management.
Yes. Zenergi supports commercial and multi-site organisations and plans inspection programmes to minimise disruption. A consistent reporting approach can help stakeholders prioritise sites, compare opportunities and coordinate capital planning.
The expected change in annual and seasonal electricity consumption should be shared with the energy procurement team. It can then be considered alongside budget priorities, risk appetite, sustainability objectives and the available fixed, flexible or green contract options.
If you are preparing an office air conditioning installation, Zenergi can help connect compliance, technical performance and energy cost planning. Start with a TM44 inspection to understand existing performance and prioritise the next steps.
Get in touch todayA TM44 inspection evaluates system efficiency, sizing, faults, controls and operating costs, helping organisations decide whether to optimise, repair or replace their A/C systems.
The report findings can support installation planning, forecast future electricity demand and ensure energy procurement reflects expected changes in consumption.
