A common pattern in industrial fit-out disasters: the tenant totals up their production equipment (ovens, cold room, exhaust fans, packaging line) and gets a number that seems manageable. They move in. The breakers trip constantly. The reason is almost always the same: air conditioning was either forgotten or drastically underestimated.
Industrial air conditioning in Singapore is not a line item. It is a primary load driver. And it runs at full capacity almost all year.
Why Aircon Load Is Larger Than Most People Think
Residential aircon is sized for a few rooms. Industrial aircon serves large open volumes: 2,000 sq ft, 5,000 sq ft, more. The compressor sizes are proportionally larger.
In Singapore’s climate, industrial aircon units run at or near peak load for most of the working day. There is no “off season.” A factory with poor insulation or significant internal heat generation from equipment will have the aircon running continuously.
A single 5-horsepower (3.7 kW) industrial aircon compressor draws roughly 15 amperes on a three-phase supply. A typical 2,000 sq ft food production unit might have three to five such units. That is 45–75 amperes just for air conditioning, before any production equipment runs.
High-bay industrial spaces, which often have minimal insulation and large exposed roof areas, can require even more aggressive cooling capacity.
Why Process Load Estimation Gets It Wrong
When operators list their production equipment, they tend to focus on the largest items: the oven, the cold room compressor, the industrial mixer. They often miss:
- Exhaust fans: industrial exhaust systems can draw 1–5 kW each
- Make-up air units: these condition incoming air and run continuously alongside exhaust
- Conveyors: belt conveyors, roller conveyors, often underestimated at 0.5–3 kW per unit
- Packaging machines: sealers, label printers, carton erectors
- Lighting: high-bay industrial fittings at 100–400W each, multiplied across a large space
- Auxiliary equipment: water booster pumps, compressed air dryers, dehumidifiers
And critically: start-up current. Motors and compressors do not start at their running current. They draw 3–7× their running current for the 1–3 seconds it takes to get up to speed. If multiple pieces of equipment start simultaneously, which is common at the beginning of a production shift, the combined start-up surge can trip the main breaker even if the running load is within capacity.
Separate the Two in Your Estimation
Create two columns when you do your load estimate:
Aircon / Comfort column:
- All fan coil units and their compressors
- Make-up air units
- Mechanical ventilation fans that serve occupant comfort (not process exhaust)
- Estimated at continuous full load for Singapore climate
Process / Production column:
- All production equipment (ovens, cold rooms, compressors, machinery)
- Process exhaust fans and fire suppression systems
- Refrigeration
- Industrial lighting
- Miscellaneous process support equipment
Total each column separately. This does two things: it helps you understand which category dominates your demand, and it helps your LEW design a distribution system that separates critical process loads from comfort loads.
Separating the two also matters operationally. If the aircon trips, you do not want it to knock out your production line. If the production line trips, you probably still want the lights on.
Practical Example: Small Food Factory
A 2,000 sq ft central kitchen in a flatted factory.
Process load:
| Equipment | kW |
|---|---|
| Deck oven (2 units) | 12 |
| Cold room compressor | 4 |
| Proofer | 3 |
| Exhaust fan | 2.5 |
| Mixer and prep tables | 3 |
| Packaging station | 1.5 |
| Production lighting | 2 |
| Process subtotal | 28 kW |
Aircon load:
| Equipment | kW |
|---|---|
| 3 × fan coil units (industrial) | 12 |
| Compressor serving all units | 6 |
| Aircon subtotal | 18 kW |
Combined: 46 kW maximum demand
The unit has a 50 kVA allocation. At 0.85 power factor, usable power is approximately 42.5 kW. Estimated demand of 46 kW exceeds the allocation. The unit cannot accommodate this operation without an upgrade.
Result: the operator needs to either negotiate a higher allocation (60–70 kVA), install more energy-efficient equipment, or find a unit with greater capacity.
What to Do If the Numbers Are Tight
If your estimated demand is within 80% of the unit’s usable capacity, you are in a precarious position. Singapore’s grid is reliable, but any growth in your operation (a second oven, an additional cold room) will push you over the limit.
Discuss with your LEW:
- Can diversity factors be applied more precisely? (Different equipment runs at different times; a smart LEW can model this)
- Can energy-efficient equipment reduce actual draw? (Inverter-driven aircon, variable-speed motors)
- Should the distribution be designed to shed non-critical loads first?
Before signing the lease:
- Negotiate a higher electrical allocation if possible
- Get a formal LEW load assessment before committing
- Include power upgrade as a contingency line item in your fit-out budget
For a step-by-step load estimation walkthrough, see How to Estimate Power Needs. For cost ranges if an upgrade is required, see Power Upgrade Costs & Timelines.
References
[1] EMA — Acts & Regulations (Electricity Supply). https://www.ema.gov.sg/regulations-licences/regulations/acts-regulations
[2] EMA — Electricity Legislation and Regulations. https://www.ema.gov.sg/Licensees_Electricity_Legislation_and_Regulations.aspx
[3] SP Group — How to Apply for Electricity Connection (Handbook). https://www.spgroup.com.sg/dam/jcr:66289889-80d2-4559-a479-a804d5323f19/How%20to%20Apply%20for%20Electricity%20Connection.pdf
[4] EMA — Electrical Worker Licences. https://www.ema.gov.sg/regulations-licences/licences/worker-licences/electrical-technicians-licence
[5] MOM — Workplace Safety and Health Act. https://www.mom.gov.sg/workplace-safety-and-health
[6] JTC Corporation — Industrial Space Information. https://www.jtc.gov.sg/find-space/