Our take in 30 seconds
Best for: mild climates or homes with backup heatStrengths
- Uses newer, lower-impact R-454B refrigerant
Good to know
- Only 50% of its heat output remains at 5°F; plan on backup heat in hard freezes
- Single-stage compressor runs on/off at full power, so it is less smooth than inverter models
Running-cost calculator
Pre-filled with EIA prices · edit any fieldUses the base certified SEER2 (15.2) and HSPF2 (8.5). Assumes the unit is correctly sized. How we calculate.
Heating capacity as it gets colder
A heat pump's output falls as outdoor temperature drops. This is the certified heat output of the Trane 5TWX5042A1 at the three ENERGY STAR test temperatures (cooling capacity is 41,500 BTU/h for reference).
Retention at 17°F: 66% · at 5°F: 50%. Learn how to use these numbers in our cold-climate guide.
Estimated running cost in every state
Same unit, very different bills: from about $1,127 a year in Louisiana to $4,279 in Maine, driven by local electricity prices and how much heating or cooling the climate needs. Click a column to sort.
| State | Price | Heating | Cooling | Total / yr |
|---|---|---|---|---|
| Louisiana | 12.87¢ | $424 | $703 | $1,127 |
| Florida | 14.99¢ | $317 | $982 | $1,300 |
| Washington | 14.63¢ | $1,170 | $140 | $1,310 |
| Mississippi | 14.43¢ | $611 | $709 | $1,320 |
| Nevada | 12.72¢ | $718 | $625 | $1,343 |
| Tennessee | 13.42¢ | $884 | $476 | $1,360 |
| Oregon | 15.92¢ | $1,199 | $196 | $1,394 |
| Arizona | 15.05¢ | $496 | $904 | $1,400 |
| North Carolina | 14.95¢ | $915 | $531 | $1,445 |
| Kentucky | 13.80¢ | $1,039 | $414 | $1,454 |
| Arkansas | 14.37¢ | $879 | $589 | $1,468 |
| South Carolina | 15.76¢ | $816 | $688 | $1,504 |
| Utah | 13.31¢ | $1,190 | $327 | $1,517 |
| Georgia | 15.90¢ | $823 | $695 | $1,518 |
| Texas | 15.91¢ | $674 | $869 | $1,543 |
| Alabama | 16.33¢ | $845 | $713 | $1,559 |
| Idaho | 13.37¢ | $1,321 | $256 | $1,577 |
| Oklahoma | 14.82¢ | $976 | $607 | $1,583 |
| New Mexico | 16.51¢ | $1,165 | $451 | $1,616 |
| Nebraska | 13.54¢ | $1,338 | $333 | $1,671 |
| West Virginia | 16.31¢ | $1,382 | $356 | $1,738 |
| Missouri | 16.02¢ | $1,282 | $481 | $1,763 |
| Virginia | 17.64¢ | $1,245 | $530 | $1,775 |
| Kansas | 15.47¢ | $1,310 | $465 | $1,775 |
| Wyoming | 14.43¢ | $1,698 | $197 | $1,895 |
| Colorado | 17.17¢ | $1,616 | $328 | $1,944 |
| North Dakota | 13.31¢ | $1,816 | $164 | $1,980 |
| Indiana | 17.02¢ | $1,602 | $395 | $1,997 |
| Delaware | 18.70¢ | $1,496 | $511 | $2,007 |
| Montana | 15.57¢ | $1,832 | $191 | $2,023 |
| South Dakota | 15.15¢ | $1,782 | $269 | $2,051 |
| California | 29.75¢ | $1,260 | $812 | $2,072 |
| Iowa | 17.06¢ | $1,846 | $349 | $2,196 |
| Ohio | 19.38¢ | $1,824 | $423 | $2,247 |
| Maryland | 21.40¢ | $1,712 | $584 | $2,296 |
| Illinois | 19.32¢ | $1,909 | $422 | $2,331 |
| Minnesota | 17.20¢ | $2,185 | $258 | $2,444 |
| Pennsylvania | 21.77¢ | $2,049 | $476 | $2,524 |
| Wisconsin | 19.41¢ | $2,284 | $318 | $2,601 |
| New Jersey | 24.61¢ | $2,085 | $605 | $2,689 |
| District of Columbia | 25.98¢ | $1,956 | $780 | $2,736 |
| Connecticut | 24.51¢ | $2,538 | $435 | $2,972 |
| Michigan | 22.99¢ | $2,597 | $377 | $2,973 |
| Vermont | 23.84¢ | $2,917 | $293 | $3,210 |
| Rhode Island | 28.18¢ | $2,917 | $462 | $3,379 |
| Hawaii | 47.18¢ | $111 | $3,349 | $3,460 |
| New York | 28.65¢ | $2,966 | $508 | $3,475 |
| New Hampshire | 27.64¢ | $3,252 | $377 | $3,629 |
| Massachusetts | 30.48¢ | $3,299 | $499 | $3,798 |
| Alaska | 29.41¢ | $4,152 | $80 | $4,232 |
| Maine | 32.11¢ | $3,929 | $351 | $4,279 |
Similar-size alternatives
Other ducted split system units within ±15% of this model's cooling capacity, sorted by efficiency. Cost difference is versus the Trane 5TWX5042A1 at U.S.-average rates.
| Model | Cooling BTU/h | SEER2 | HSPF2 | 5°F kept | Est. yearly cost | |
|---|---|---|---|---|---|---|
| Ruud UP19AY48AJVC | 45,500 | 18–19 | 10 | 92% | $1,827 (−$86) | Compare |
| Heil B5H3V48*K*AAA* | 46,500 | 20–23 | 9.5 | 76% | $1,963 (+$50) | Compare |
| Tempstar T5H3V48*K*AAA* | 46,500 | 19.5–23 | 9.5 | 72% | $2,113 (+$200) | Compare |
| Bryant 37MUHAQ36AA3 | 36,000 | 15.8–18 | 10.3 | 103% | $1,527 (−$386) | Compare |
| Panasonic CU-HM36BAHU | 36,000 | 15.6–17.4 | 10.3 | 103% | $1,533 (−$380) | Compare |
| MrCool CENTRAL-36-HP-C-230B00-O | 36,000 | 15.2–17.4 | 10.3 | 103% | $1,545 (−$368) | Compare |
Full specifications
| Brand | Trane |
| Outdoor model | 5TWX5042A1 |
| Certified by | Trane and American Standard Heating and Air Conditioning |
| Product type | Ducted split system |
| Compressor | Single-stage |
| Refrigerant | R-454B |
| Cooling capacity | 41,500 BTU/h |
| Nominal size | 3.5 tons |
| SEER2 (certified range) | 15.2 – 16.5 |
| EER2 (best) | 12 |
| HSPF2 (best) | 8.5 |
| Heating capacity @ 47°F | 40,000 BTU/h |
| Heating capacity @ 17°F | 26,200 BTU/h |
| Heating capacity @ 5°F | 20,000 BTU/h |
| COP @ 5°F | 2.3 |
| ENERGY STAR cold-climate | No |
| Certified indoor pairings | 231 |
| Latest certification | 2026-06 |
Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), retrieved November 7, 2026. Capacities and HSPF2 are the highest values across certified pairings; confirm your exact system's AHRI reference number with your installer.
Frequently asked questions
How much does the Trane 5TWX5042A1 cost to run per year?
At the U.S. average residential electricity price of 18.16¢/kWh and typical national heating and cooling hours, we estimate about $1,913 per year ($1,367 heating, $545 cooling). It ranges from about $1,127 in Louisiana to $4,279 in Maine.
Does the Trane 5TWX5042A1 work in cold weather?
It is not ENERGY STAR cold-climate certified. It delivers 20,000 BTU/h at 5°F (50% of its 47°F capacity), so in very cold climates expect more reliance on backup heat.
What size is the Trane 5TWX5042A1?
It is rated at 41,500 BTU/h of cooling, roughly 3.5 tons, and 40,000 BTU/h of heating at 47°F. Proper sizing should be confirmed with a Manual J load calculation.