| 2000 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Total Cooling System Stock (thousands) | 4,030 | 8,699 | 9,044 | 9,117 | 9,206 | 9,312 | 9,436 | 9,576 | 9,734 | |
System Stock by Type (thousands) | ||||||||||
| Room | 1,425 | 3,281 | 3,393 | 3,308 | 3,230 | 3,158 | 3,091 | 3,030 | 2,974 | |
| Central | 2,605 | 5,418 | 5,652 | 5,809 | 5,976 | 6,155 | 6,344 | 6,546 | 6,760 | |
Shares (%) | ||||||||||
| Room | 35.4 | 37.7 | 37.5 | 36.3 | 35.1 | 33.9 | 32.8 | 31.6 | 30.6 | |
| Central | 64.6 | 62.3 | 62.5 | 63.7 | 64.9 | 66.1 | 67.2 | 68.4 | 69.4 | |
New Unit Efficiencies | ||||||||||
| Room (EER)1 | 9.4 | 11.2 | 11.2 | 11.3 | 11.3 | 11.4 | 11.5 | 11.5 | 11.6 | |
| Central (SEER)2 | 10.3 | 13.3 | 13.4 | 13.5 | 13.5 | 13.6 | 13.7 | 13.7 | 13.8 | |
Stock Efficiencies | ||||||||||
| Room (EER)1 | 8.3 | 10.7 | 10.8 | 10.9 | 10.9 | 11.0 | 11.1 | 11.2 | 11.2 | |
| Central (SEER)2 | 9.6 | 11.8 | 12.0 | 12.2 | 12.4 | 12.7 | 12.9 | 13.1 | 13.3 | |
Unit Capacity Ratio (Btu/hour) | ||||||||||
| Room | 9,898 | 9,129 | 9,131 | 9,218 | 9,285 | 9,353 | 9,472 | 9,489 | 9,507 | |
| Central | 33,466 | 33,282 | 33,291 | 33,140 | 32,989 | 32,827 | 32,634 | 32,637 | 32,640 | |