Portable vs. window air conditioner
For the same cooling, a typical portable unit costs about $81 a year more to run than a window unit in the 10,000 BTU class.
A typical certified 10,000 BTU (SACC) portable unit has 7.9 CEER and costs about $171 a year; ENERGY STAR certified window units that cool as much have a median CEER of 15.0 and cost about $90. A portable unit makes sense when a window unit will not fit.
The certified numbers, size by size
| Real cooling (SACC) | Portable CEERtypical | Window CEERtypical | Portable per year | Window per year | Window saves |
|---|---|---|---|---|---|
| 5,000 BTU | 6.2 | 13.7 | $109 | $49 | $60 |
| 6,000 BTU | 6.6 | 15.1 | $123 | $54 | $69 |
| 8,000 BTU | 7.3 | 15.0 | $148 | $72 | $76 |
| 10,000 BTU | 7.9 | 15.0 | $171 | $90 | $81 |
| 12,000 BTU | 12.8 | 15.0 | $127 | $108 | $19 |
Typical = median CEER of the DOE certified portable units and the ENERGY STAR certified window units (about the same cooling, within 15%). Yearly cost at 750 hours and 18.0¢/kWh. Portable cooling is the SACC, the cooling the unit delivers, so the two are compared fairly. One caveat: ENERGY STAR window units are the more efficient part of the window market, so an average window unit sold costs somewhat more than shown; the portable unit is still less efficient. What SACC means.
The best of each, at about 10,000 BTU
- Best portable: Midea MAP12S1TBL14.7 CEER
- Best dual-hose portable overall: Midea MAP12S1TBL14.7 CEER
- Best window unit near 10,000 BTU: Midea MAH09B1AGR17.6 CEER
Which fits your room
Side by side
| Portable air conditioner | |
|---|---|
| Fits | Any room with a way to vent: window kit, sliding-door kit, a hole in the wall. No window? |
| Moves between rooms | Yes, on wheels, but heavy and with hoses to reconnect. |
| Efficiency | Lower: it works inside the room, and heat leaks back in through the hose and case. |
| Noise | Usually louder, because the compressor is in the room. |
| Window air conditioner | |
| Fits | A window that opens wide enough (some designs also need an upward-sliding sash). Casement and sliders need a special unit. Window units, ranked. |
| Moves between rooms | Only with effort: it sits in the window. |
| Efficiency | Higher: the compressor and exhaust stay outside. |
| Noise | Usually quieter indoors. |
Questions
- Is a portable air conditioner as good as a window unit?
- Not on efficiency. At the same real cooling, the median ENERGY STAR certified window unit has a higher CEER than the median portable unit in every size: 5,000 BTU 13.7 against 6.2, 6,000 BTU 15.1 against 6.6, 8,000 BTU 15.0 against 7.3, 10,000 BTU 15.0 against 7.9, 12,000 BTU 15.0 against 12.8. The best dual-hose portable units (up to 14.7 CEER) come close to a typical window unit.
- Which costs more to run, a portable or a window air conditioner?
- The portable one, for the same cooling. A typical 10,000 BTU (SACC) portable unit costs about $171 a year at 750 hours and 18.0¢/kWh, against about $90 for a window unit that cools as much.
- When should I choose a portable air conditioner?
- When a window unit will not fit or is not allowed: casement and sliding windows, windows that do not open far, buildings that ban window units, rooms with no window at all (with a vent kit), or when you want to move one unit between rooms. If a window unit fits, it is almost always the better buy.
- Are portable air conditioners louder?
- Usually, because the compressor sits in the room. A window unit keeps its compressor and exhaust outside. Noise is not part of the certified data for either type, so compare the decibel rating at the lowest fan speed on the maker's spec sheet.