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ASHRAE vs SACC Portable AC Calculator
Estimate the cooling load your room needs, then compare that target with a portable air conditioner's published DOE SACC. The calculator also explains why the larger ASHRAE/marketing BTU number cannot be converted to SACC with one universal percentage.
Updated for 2026 using the current DOE portable-air-conditioner test procedure and current manufacturer rating examples.
On this page: Calculator · Sizing chart · SACC vs BTU · Single vs dual hose · Sizing tips · Alternatives · FAQ
Can you install a window unit? A window AC is typically more efficient and cheaper to run. For a deeper factor-by-factor cooling load, use the BTU calculator.
Portable AC sizing in one sentence
Calculate the room's cooling requirement first, then choose a portable AC whose published DOE SACC meets or exceeds that target. Do not assume that an 8,000, 10,000, 12,000, or 14,000 ASHRAE/marketing label converts to SACC by a fixed percentage. Browse portable ACs and verify the model's SACC in the specifications.
Portable ACs are typically less efficient than window units. If you can install one, try the window AC calculator. For heating needs, try the space heater calculator.
Portable AC sizing chart by room size
Start with the room cooling-capacity target, then compare that number with the portable AC's published DOE SACC. The baseline capacities below come from ENERGY STAR room-air-conditioner sizing guidance for an 8 ft ceiling before adjustments for sun, occupants, kitchens, climate, or insulation.
| Room (sq ft) | Baseline cooling target | Portable AC shopping rule |
|---|---|---|
| 100–150 | 5,000 BTU/h | Published SACC ≥ 5,000 |
| 150–250 | 6,000 BTU/h | Published SACC ≥ 6,000 |
| 250–300 | 7,000 BTU/h | Published SACC ≥ 7,000 |
| 300–350 | 8,000 BTU/h | Published SACC ≥ 8,000 |
| 350–400 | 9,000 BTU/h | Published SACC ≥ 9,000 |
| 400–450 | 10,000 BTU/h | Published SACC ≥ 10,000 |
| 450–550 | 12,000 BTU/h | Published SACC ≥ 12,000 |
| 550–700 | 14,000 BTU/h | High-capacity portable choices are limited; compare alternatives |
Browse common retail label sizes
Retail titles may emphasize ASHRAE/marketing BTU. Open the specifications and verify the published SACC before treating a model as a match.
For rooms above the practical range of available portable ACs, compare a window AC or mini split.
ASHRAE vs SACC: what’s the difference?
SACC means Seasonally Adjusted Cooling Capacity. DOE defines SACC specifically in the federal test procedure for portable air conditioners. The procedure accounts for effects such as duct heat transfer and infiltration, so SACC is the portable AC capacity figure to use when comparing the unit with your room's cooling requirement.
Many portable-AC product pages also show a larger ASHRAE/marketing BTU figure. There is no universal ASHRAE-to-SACC conversion percentage. The relationship varies by model and design, so this calculator does not manufacture an approximate SACC from the larger label number.
| Current manufacturer example | ASHRAE / marketing | Published SACC |
|---|---|---|
| LG LP0626PGF | 10,000 BTU | 6,000 BTU |
| Midea MP08DRWBA3RCM | 12,000 BTU | 8,000 BTU |
| Whynter ARC-1030WN | 12,000 BTU | 10,000 BTU |
| Whynter ARC-1230WN | 14,000 BTU | 12,000 BTU |
Those examples range from 60% to more than 80% of the larger ASHRAE/marketing figure, which is why a fixed 0.65 or 0.72 conversion can mis-size a unit. Use the model's published SACC instead.
Primary reference: DOE / 10 CFR Appendix CC portable AC test procedure.
Shop by retail label — then verify published SACC
Retail BTU labels are not interchangeable with SACC. Open the model specifications and confirm that its published SACC meets the calculator target.
Single-hose vs dual-hose portable AC
A single-hose portable AC exhausts hot air out the window, but it also pulls replacement air from the rest of your home (or from outside through gaps). This creates negative pressure and can pull warmer outdoor or adjacent-space air into the conditioned room.
Dual-hose models bring outside air for the condenser separately, so they don't depressurize the room. Dual-hose designs can reduce that depressurization effect by separating condenser intake and exhaust air. Actual performance still varies by model, so compare the published DOE SACC rather than assuming a fixed advantage.
| Factor | Single hose | Dual hose |
|---|---|---|
| Cooling efficiency | Varies by model; can create room depressurization | Varies by model; reduces single-hose depressurization effect |
| Room pressure | Creates negative pressure | Neutral pressure |
| Price | Varies by model and features | Varies by model and features |
| Setup complexity | Simpler (one hose) | Slightly more (two hoses) |
| Best for | Occasional use, small rooms | Primary cooling, hot climates, larger rooms |
If your room gets lots of sun, a window insulation kit ($10–30) reduces heat gain and makes any portable AC more effective.
Portable AC sizing tips
Hose and sealing
Keep the vent hose short and as straight as the manufacturer permits. Extra length, tight bends, or unsupported extensions can increase heat transfer and airflow resistance, but there is no universal percentage loss per foot. Seal air leaks around the window kit, door gaps, and electrical outlets with weatherstripping to stop hot air infiltration.
Humidity and noise
Humidity matters: in humid areas, the AC works harder on dehumidification. Consider a dedicated dehumidifier to offload that work, or choose a dual-hose unit which handles humidity better. For whole-house fresh-air and humidity management, an HRV or ERV handles ventilation without the cooling load penalty. Bedroom use: portable ACs typically run 50–56 dB. If you need quiet sleep, a mini split (19–32 dB indoors) is significantly quieter. For any portable in a bedroom, look for a model with “sleep mode” that drops to the lowest fan speed.
Helpful add-ons: hygrometer ($10–15) · weatherstripping ($5–15) · thermal leak detector ($25–40) · energy monitor ($20–30).
Reduce your cooling load before buying
Small improvements can let you buy a smaller, cheaper portable AC:
Window film / reflective insulation ($10–30) — blocks solar heat through south/west windows. Weatherstripping ($5–15) — seal gaps that let hot air in. Door sweeps ($8–15) — block drafts under doors. Outlet gaskets ($5) — stop air infiltration on exterior walls.
Dropping from a 12,000 to a 10,000 BTU unit saves $50–$100 on the unit and uses 15–20% less electricity. A ceiling fan makes a room feel 3–4°F cooler, often letting you set the AC higher. Add smart scheduling with a smart AC controller ($25–60) for auto-off when you leave.
When to choose something other than a portable AC
| Situation | Better option | Why |
|---|---|---|
| Double-hung windows available | Window AC | More efficient, quieter, cheaper to run |
| Need heating too | Mini split or heat pump | Year-round heating + cooling in one system |
| Room over 500 sq ft | Mini split or window AC | Portable ACs struggle above 500 sq ft |
| Bedroom — noise is critical | Mini split | Compressor is outside (19–32 dB indoors) |
| Whole-home cooling needed | Central AC | One system cools the entire home via ducts |
| Humidity is the main problem | Dehumidifier | Removes moisture more efficiently than AC alone |
| Detached garage or workshop | Garage heater or mini split | Portable ACs aren't optimized for garages — a dedicated unit heater is more effective |
Sources and methodology
SACC terminology and testing are based on the U.S. Department of Energy portable air conditioner program and 10 CFR Part 430, Appendix CC. Baseline room-capacity targets use ENERGY STAR room air conditioner sizing guidance. The ASHRAE/SACC examples above come from current LG, Midea, and Whynter manufacturer specifications.
The calculator is a planning tool, not a DOE laboratory test or Manual J load calculation. It estimates room cooling demand and tells you what published SACC to look for; it does not calculate a product's SACC.
Frequently asked questions
Is a portable AC as effective as a window AC?
Portable and window ACs use different product designs and should be compared using the rating system applicable to each product. Portable ACs keep the refrigeration system indoors and exhaust heat through a duct, while a window unit places the hot side largely outside the room. If a window unit is practical, compare its required BTU size with the window AC calculator.
What portable AC size do I need for a bedroom?
Calculate the bedroom's cooling requirement, then choose a portable AC whose published DOE SACC meets or exceeds that target. ENERGY STAR's room-AC sizing table starts a 100–150 sq ft room at 5,000 BTU/h and a 150–250 sq ft room at 6,000 BTU/h before adjustments. Use the calculator above for climate, insulation, ceiling height, sun, and occupancy, then verify SACC in the product specifications.
What is SACC and why can it be lower than the BTU in a product title?
SACC means Seasonally Adjusted Cooling Capacity. DOE defines it for portable air conditioners under Appendix CC. Many products also advertise a larger ASHRAE or marketing BTU figure, but SACC incorporates portable-AC effects such as duct heat transfer and infiltration. Use the published SACC when comparing a portable AC with the room-load target from this calculator.
Can I convert ASHRAE BTU to SACC with a fixed percentage?
No. There is no reliable universal conversion. Current manufacturer examples include 10,000 ASHRAE / 6,000 SACC, 12,000 / 8,000, 12,000 / 10,000, and 14,000 / 12,000. Because the relationship varies substantially by model, use the exact SACC published for the portable AC you are considering.
Single hose vs dual hose — which is better?
A single-hose portable AC uses conditioned-room air for the condenser and exhausts it outdoors, which can depressurize the room and draw replacement air through leaks. Dual-hose designs separate condenser intake and exhaust air and can reduce that effect. Do not assume a fixed SACC percentage for either design; compare the published SACC of the actual models.
How much electricity does a portable AC use?
Electricity use is product-specific. Use the unit's rated watts from its EnergyGuide label, nameplate, or specifications. Monthly energy is approximately watts ÷ 1,000 × hours per day × 30. Enter rated watts, expected hours per day, and your electricity rate in the calculator for a planning estimate, or track actual use with an energy monitor.
Can I cool two rooms with one portable AC?
Portable AC room-capacity ratings are intended for the conditioned space where the unit operates. Airflow through a doorway depends on the layout, temperature difference, fans, and return path, so there is no reliable fixed percentage for an adjacent room. For separate rooms, calculate each space independently or consider a multi-zone mini split.
What's the fastest way to get a more precise load calculation?
Use the BTU calculator for a more detailed room estimate including windows, ductwork, and room type. For equipment selection that requires a professional design load, use an ACCA Manual J calculation or request an HVAC quote.
What does 12,000 BTU ASHRAE / 8,000 BTU SACC mean?
It means the portable AC is being shown with two different capacity figures. The larger 12,000 BTU figure is the ASHRAE/marketing capacity, while 8,000 BTU is the model's published DOE SACC. For portable-AC sizing on this page, compare the 8,000 BTU SACC with your calculated cooling-load target.
Save on summer cooling costs
A smart AC controller ($25–60) adds scheduling and auto-off when you leave — saving 10–20% on electricity. Works with any portable AC that has a remote control. Estimate savings with the energy cost calculator.
Want a longer-term solution? Compare: window AC · mini split · SEER savings · equipment by BTU.