Portable AC Sizing Calculator (SACC)

Translates marketing BTU to DOE SACC and checks it against your room.

Room area (m²)Advertised (ASHRAE) BTU (BTU/h)

Realistic SACC estimate (BTU/h)

Room requirement (BTU/h)

Single-hose portables suck conditioned air out of the room and exhaust it — the DOE SACC rating (~40% lower) reflects reality. Dual-hose units fare better.

Formula

SACC ≈ 0.6 × ASHRAE BTU (single-hose); need = 20 BTU/ft²

References: US DOE 10 CFR 430 — SACC test procedure

Portable AC Sizing Calculator (SACC) is a free portable ac size for HVAC designers, technicians and energy auditors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.

About Portable AC Sizing Calculator (SACC)

Translates marketing BTU to DOE SACC and checks it against your room. The calculation implements SACC ≈ 0.6 × ASHRAE BTU (single-hose); need = 20 BTU/ft² (US DOE 10 CFR 430 — SACC test procedure). Single-hose portables suck conditioned air out of the room and exhaust it — the DOE SACC rating (~40% lower) reflects reality. Dual-hose units fare better.

How to use Portable AC Sizing Calculator (SACC)

1Enter Room area in m².
2Enter Advertised (ASHRAE) BTU in BTU/h.
3Read Realistic SACC estimate, Room requirement instantly — no submit button needed.
4Need US units? Flip the SI/Imperial toggle and every field converts.

Why use Portable AC Sizing Calculator (SACC)?

✓Implements the standard formula — SACC ≈ 0.6 × ASHRAE BTU (single-hose); need = 20 BTU/ft²
✓Reference cited on-page: US DOE 10 CFR 430 — SACC test procedure
✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
✓Built-in engineering verdict flags out-of-range results instantly
✓Runs entirely in your browser — nothing uploaded, free forever

Frequently asked questions

What formula does the Portable AC Sizing Calculator (SACC) use?+

It computes SACC ≈ 0.6 × ASHRAE BTU (single-hose); need = 20 BTU/ft², per US DOE 10 CFR 430 — SACC test procedure. The formula is displayed under the result.

What should I keep in mind when using this calculator?+

Single-hose portables suck conditioned air out of the room and exhaust it — the DOE SACC rating (~40% lower) reflects reality. Dual-hose units fare better.

Is this based on ASHRAE methods?+

The calculations follow the standard ASHRAE/ISHRAE formulations cited under the result, simplified where industry practice does the same. For permit-grade design, confirm with the full code procedure.

Is the Portable AC Sizing Calculator (SACC) free to use?+

Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.

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