Our take in 30 seconds
Best for: cold and very cold climatesStrengths
- Keeps 83% of its heat at 5°F, so backup heat rarely runs
- Variable-speed compressor: quieter, steadier temperatures and better humidity control
- Uses newer, lower-impact R-454B refrigerant
Good to know
- No notable drawbacks in the certified data.
Running-cost calculator
Pre-filled with EIA prices · edit any fieldUses the base certified SEER2 (16) and HSPF2 (9). 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 Bosch BOHA-36RTB-M18S at the three ENERGY STAR test temperatures (cooling capacity is 34,000 BTU/h for reference).
Retention at 17°F: 87% · at 5°F: 83%. Learn how to use these numbers in our cold-climate guide.
Estimated running cost in every state
Same unit, very different bills: from about $907 a year in Louisiana to $3,612 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¢ | $360 | $547 | $907 |
| Florida | 14.99¢ | $270 | $764 | $1,034 |
| Mississippi | 14.43¢ | $519 | $552 | $1,071 |
| Nevada | 12.72¢ | $611 | $487 | $1,097 |
| Washington | 14.63¢ | $995 | $109 | $1,104 |
| Tennessee | 13.42¢ | $752 | $371 | $1,122 |
| Arizona | 15.05¢ | $421 | $704 | $1,125 |
| Oregon | 15.92¢ | $1,019 | $152 | $1,171 |
| North Carolina | 14.95¢ | $777 | $413 | $1,190 |
| Arkansas | 14.37¢ | $747 | $458 | $1,205 |
| Kentucky | 13.80¢ | $883 | $323 | $1,206 |
| South Carolina | 15.76¢ | $693 | $536 | $1,229 |
| Georgia | 15.90¢ | $700 | $541 | $1,240 |
| Texas | 15.91¢ | $573 | $676 | $1,249 |
| Utah | 13.31¢ | $1,012 | $255 | $1,266 |
| Alabama | 16.33¢ | $719 | $555 | $1,274 |
| Oklahoma | 14.82¢ | $830 | $472 | $1,302 |
| Idaho | 13.37¢ | $1,123 | $199 | $1,322 |
| New Mexico | 16.51¢ | $991 | $351 | $1,341 |
| Nebraska | 13.54¢ | $1,137 | $259 | $1,396 |
| West Virginia | 16.31¢ | $1,174 | $277 | $1,452 |
| Missouri | 16.02¢ | $1,089 | $374 | $1,464 |
| Virginia | 17.64¢ | $1,058 | $412 | $1,471 |
| Kansas | 15.47¢ | $1,114 | $362 | $1,475 |
| Wyoming | 14.43¢ | $1,443 | $153 | $1,596 |
| Colorado | 17.17¢ | $1,374 | $255 | $1,629 |
| Delaware | 18.70¢ | $1,272 | $397 | $1,669 |
| Indiana | 17.02¢ | $1,362 | $307 | $1,669 |
| North Dakota | 13.31¢ | $1,544 | $127 | $1,671 |
| California | 29.75¢ | $1,071 | $632 | $1,703 |
| Montana | 15.57¢ | $1,557 | $149 | $1,706 |
| South Dakota | 15.15¢ | $1,515 | $209 | $1,724 |
| Iowa | 17.06¢ | $1,570 | $272 | $1,841 |
| Ohio | 19.38¢ | $1,550 | $329 | $1,880 |
| Maryland | 21.40¢ | $1,455 | $455 | $1,910 |
| Illinois | 19.32¢ | $1,623 | $328 | $1,951 |
| Minnesota | 17.20¢ | $1,858 | $201 | $2,059 |
| Pennsylvania | 21.77¢ | $1,742 | $370 | $2,112 |
| Wisconsin | 19.41¢ | $1,941 | $247 | $2,188 |
| New Jersey | 24.61¢ | $1,772 | $471 | $2,243 |
| District of Columbia | 25.98¢ | $1,663 | $607 | $2,270 |
| Connecticut | 24.51¢ | $2,157 | $339 | $2,495 |
| Michigan | 22.99¢ | $2,207 | $293 | $2,500 |
| Hawaii | 47.18¢ | $94 | $2,607 | $2,701 |
| Vermont | 23.84¢ | $2,479 | $228 | $2,707 |
| Rhode Island | 28.18¢ | $2,480 | $359 | $2,839 |
| New York | 28.65¢ | $2,521 | $396 | $2,917 |
| New Hampshire | 27.64¢ | $2,764 | $294 | $3,058 |
| Massachusetts | 30.48¢ | $2,804 | $389 | $3,193 |
| Alaska | 29.41¢ | $3,529 | $62 | $3,592 |
| Maine | 32.11¢ | $3,339 | $273 | $3,612 |
Similar-size alternatives
Other ducted split system units within ±15% of this model's cooling capacity, sorted by efficiency. Cost difference is versus the Bosch BOHA-36RTB-M18S at U.S.-average rates.
| Model | Cooling BTU/h | SEER2 | HSPF2 | 5°F kept | Est. yearly cost | |
|---|---|---|---|---|---|---|
| Ruud UP19AY36AJVC | 34,200 | 19–21 | 10 | 87% | $1,353 (−$233) | Compare |
| Payne 37MUHAQ30AA3 | 30,000 | 15.3–17.5 | 10.8 | 98% | $1,306 (−$280) | Compare |
| Midea MO1HE-H30B-2A | 30,000 | 15.2–17.5 | 10.8 | 98% | $1,309 (−$278) | Compare |
| Bryant 37MUHAQ36AA3 | 36,000 | 15.8–18 | 10.3 | 103% | $1,527 (−$60) | Compare |
| Daikin DH9VSA361CA* | 34,200 | 16.9–21 | 10 | 100% | $1,398 (−$189) | Compare |
| Panasonic CU-HM36BAHU | 36,000 | 15.6–17.4 | 10.3 | 103% | $1,533 (−$54) | Compare |
Full specifications
| Brand | Bosch |
| Outdoor model | BOHA-36RTB-M18S |
| Certified by | Bosch Thermotechnology Corporation |
| Product type | Ducted split system |
| Compressor | Variable-speed (inverter) |
| Refrigerant | R-454B |
| Cooling capacity | 34,000 BTU/h |
| Nominal size | 3 tons |
| SEER2 (certified range) | 16 – 16.5 |
| EER2 (best) | 11 |
| HSPF2 (best) | 9 |
| Heating capacity @ 47°F | 36,000 BTU/h |
| Heating capacity @ 17°F | 31,200 BTU/h |
| Heating capacity @ 5°F | 30,000 BTU/h |
| COP @ 5°F | 1.9 |
| ENERGY STAR cold-climate | Yes |
| Certified indoor pairings | 12 |
| Latest certification | 2026-04 |
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 Bosch BOHA-36RTB-M18S 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 $1,587 per year ($1,162 heating, $424 cooling). It ranges from about $907 in Louisiana to $3,612 in Maine.
Does the Bosch BOHA-36RTB-M18S work in cold weather?
Yes. It is ENERGY STAR cold-climate certified and delivers 30,000 BTU/h at 5°F, 83% of its 47°F capacity, with a COP of 1.9 at 5°F.
What size is the Bosch BOHA-36RTB-M18S?
It is rated at 34,000 BTU/h of cooling, roughly 3 tons, and 36,000 BTU/h of heating at 47°F. Proper sizing should be confirmed with a Manual J load calculation.