50% energy savings: what the ACMV contract must include

Can you name the last time your ACMV contractor measured the air temperature in a resident's room, rather than the return air at the AHU?

If you hesitated, you are in good company. Most building managers in Singapore can produce a service report. Far fewer can produce a thermal comfort record that would satisfy a regulator, an insurer, or a hospital's infection control team. That gap matters because in hospitals and care homes, the people breathing your air cannot open a window or move to a cooler room. They are the occupiers, and their renewal decision — or their complaint — lands on your desk.

The stakes: who owns thermal comfort when the occupant cannot leave

In a hospital or care home, the ACMV system is not a comfort amenity. It is part of clinical care and part of the building's licence to operate. The Building and Construction Authority (BCA) regulates building performance, and the Ministry of Sustainability and the Environment (MSE) has set a national standard of 25°C or higher for indoor air-conditioning through the Go 25 movement. That standard is voluntary, but it signals where inspection and audit attention is heading. If your contract does not require temperature and humidity records at the point of occupancy, you have no evidence that your building meets either the comfort expectation or the energy target. When a regulator or an insurer asks, the name on the response is yours.

What does an ACMV maintenance contract include? The scope that actually protects you

A standard ACMV maintenance contract in Singapore covers preventive servicing of the air handling units, fan coil units, chillers, cooling towers, pumps, and filters. It includes quarterly or monthly cleaning, belt and bearing checks, refrigerant top-ups, and a service report. That is the baseline. It is also not enough for a hospital or care home.

What the contract must also include, if you are to hold the certificates an auditor will ask for, is the following:

• Thermal comfort monitoring at the occupied zone. Not at the return air grille. The contract should specify temperature and relative humidity readings taken in patient rooms, wards, and common areas, with a defined acceptable range. The BCA's Alternative Cooling Technologies guidance points to the CBE Thermal Comfort Tool for assessing acceptability under different operating conditions. Your contractor should be using something equivalent, and recording the result.
• Filter change and pressure differential logs. In a care home, a clogged filter is not just an energy problem. It is an air quality problem. The contract should require differential pressure readings across each filter bank, with a change-out threshold written into the schedule.
• Ventilation rate verification. Hospitals and care homes have specific outdoor air requirements for infection control. The contract should include periodic measurement of fresh air intake, not just a visual check that the damper is open.
• Chiller efficiency and refrigerant records. The contract should require kW/RT readings and refrigerant usage logs. These are the figures that support your energy reporting and your Go 25 commitments.
• Response times for temperature complaints. A care home cannot wait three days for a contractor to attend a hot ward. The contract should specify a maximum response time for thermal comfort complaints, and a process for after-hours escalation.

If your current contract does not name these items, you are paying for maintenance without buying evidence. The HDB's guidance on maintaining air conditioners is written for flat owners, but the principle applies to your portfolio: regular servicing is not the same as documented performance.

The evidence the board will ask for

When a director asks whether the building is compliant, the building manager needs to produce three things. First, the service reports for the last twelve months, signed and dated, with the thermal comfort readings attached. Second, the filter and ventilation logs, showing that the system has been maintained to the manufacturer's specification. Third, the complaint log, showing how many thermal comfort complaints were received and how quickly they were resolved.

If any of those three is missing, the board cannot answer the question either. And in a hospital or care home, the question will come from more than one direction. The Ministry of Health, the insurer, the fire safety officer, and the occupier's family all have an interest in whether the air is safe and comfortable. The Go 25 national movement has made indoor temperature a public conversation. Your contract is the document that shows whether you are part of that conversation or behind it.

Three decisions to take

First, rewrite the scope. Add thermal comfort monitoring at the occupied zone, filter differential pressure logs, ventilation rate verification, and a defined response time for temperature complaints. If your contractor cannot provide these, you are not asking for anything unusual. You are asking for the evidence that a hospital or care home requires.

Second, set a temperature target and record it. The Go 25 standard is 25°C or higher. In a care home, that may need to be adjusted for residents with specific health needs, but the target should be written down and the actual readings should be recorded against it. The BCA's guidance on alternative cooling technologies shows that energy savings of 25–50% are achievable with hybrid cooling, passive displacement cooling, and mixed mode ventilation, with payback periods of 4 to 10 years. Those figures are for new and existing buildings, and they are worth putting in front of your board when the contract comes up for renewal.

Third, test the contract before the next audit. Pick one building. Ask for the last quarter's thermal comfort readings. If they do not exist, you have found the gap. If they do exist, check whether they were taken at the occupied zone or at the return air. The difference is the difference between a certificate and a complaint.

For a related look at how maintenance contract scope is being tightened in another market, the Dubai Civil Defence's smart fire systems AMC requirements show the same pattern: regulators are moving from 'is it serviced?' to 'can you prove it performs?'

Your 60-second self-check

• Could you produce last quarter's thermal comfort readings for every hospital and care home in your portfolio, taken at the occupied zone?
• Does your ACMV contract specify a maximum response time for temperature complaints, and can you show that it was met?
• Can you name the last time your contractor measured fresh air intake rates, not just checked that the damper was open?

If you cannot answer all three with a yes, you are carrying a risk that will surface when someone more senior asks for the evidence. The free 5-minute Director's Risk Check gives you your control score for this dimension before that conversation happens. You can run the check here, and if you are not the right person to answer, you can send it to the building manager who holds the certificates.

Herman's verdict

An ACMV contract that does not require a temperature reading in the room where the patient sleeps is not a maintenance contract. It is a cleaning schedule with a service report attached. The certificate you need is the one that shows what the air was doing at the point of occupancy, and if your contractor is not producing it, you are the one who will be asked why.

— Herman