The honest answer is 'it depends on your floor' — but there's a rule of thumb that gets you close in ten seconds, and a calculator that confirms it. Here's how to size it yourself.
Enviro Air Cooler (M) Sdn Bhd · Cooling Malaysian factories since 1990 · Updated July 2026
As a rough guide, allow about 1 HP for every 285–290 sq ft of floor at a 10 ft ceiling for a comfort target (26–27°C). So a 2,000 sq ft floor lands around 7 HP. A tighter precision target (24°C with controlled humidity) needs roughly 45% more. Taller ceilings and longer run-hours push it up from there — our Cooling Calculator works out the exact size in seconds.
The quick rule of thumb
For a normal factory floor at a comfortable working temperature, size roughly 1 HP for every 285–290 sq ft at a 10 ft ceiling. It's the same starting point our engineers use before a site visit — it gets you in the right ballpark so you can plan and budget.
Two things then move the number: how cold you need it (a precision target needs more capacity than plain comfort) and how tall and hard-working the space is (higher ceilings and round-the-clock shifts add load).
HP by floor size (comfort target, ~10 ft ceiling)
| Floor area | Approx. capacity | Supplied as |
|---|---|---|
| 1,000 sq ft | ~3–4 HP | 5 HP unit |
| 2,000 sq ft | ~7 HP | 7 HP unit |
| 3,000 sq ft | ~10 HP | 10 HP unit |
| 4,000 sq ft | ~14 HP | 15 HP unit |
| 6,000 sq ft | ~21 HP | 20–25 HP (often 2 units) |
Systems are supplied in standard sizes (5, 7, 10, 15, 20, 25 HP…), so the calculator rounds your estimate up to the next standard unit. Treat this table as a planning guide, not a final spec — the exact size comes from a quick site assessment.
What changes the number
- Target temperature. A precision target (24°C, tighter humidity) needs about 45% more capacity than a comfort target — so a 2,000 sq ft precision floor is closer to 10 HP than 7.
- Ceiling height. More height means more air volume to cool. A 15 ft ceiling adds roughly half again the load of a 10 ft one for the same floor.
- Run-hours & heat load. Machines, ovens and lots of people all add heat. A hot process floor needs more than an open storage area of the same size.
A worked example
Say you run a 2,000 sq ft CNC floor at a comfortable temperature, 10 ft ceiling:
- 2,000 ÷ ~290 ≈ 7 HP.
- If you needed a tight precision target instead, add ~45% → closer to 10 HP.
- A 7 HP copper-free unit draws about 6.85 kW — roughly half the 15 HP conventional system it replaces.
Want it exact? The Cooling Calculator takes your area (or length × width × height), your target and your run-hours, and returns the recommended HP plus the monthly electricity cost against conventional AC. We then confirm it on a free site assessment. For the money side of sizing, see our guide on how much industrial air conditioning costs in Malaysia.
Frequently asked questions
How many HP do I need for a 2,000 sq ft factory?
What is the rule of thumb for factory air-con sizing?
Does a higher ceiling need more HP?
Enviro Engineering Team
Enviro Air Cooler (M) Sdn Bhd has designed, installed and serviced industrial cooling for Malaysian factories since 1990 — from evaporative coolers to copper-free industrial air conditioning and IoT cold rooms. Every figure here comes from systems we've actually installed.
Size your factory in 30 seconds
Use the Cooling Calculator for an instant HP estimate and electricity comparison, then let us confirm it on a free site assessment.
