Manual J calculator · AZ
Manual J load calculation for Arizona.
Reference data for Manual J load calculations in Arizona: ASHRAE design temperatures for 4 top metros, energy code status, and AZ ROC licensing. The calculator does not load this page's data. It asks for your project location and looks up outdoor design conditions in its own dataset, by IECC 2021 climate zone for a ZIP code or by weather station for the 10 major metros in its city list.
Reference metro
Phoenix, AZ (Maricopa County) · IECC 2015 zone 2B · winter 99% DB 42°F · summer 0.4% DB 110°F · MCWB 69°F.
0.4% DB: ASHRAE 2021 station value · Manual J 8 loads use the 1% DB
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01 · ASHRAE design conditions
Top 4 metros in Arizona - ASHRAE design temperatures.
These are the ASHRAE 99% heating and 0.4% cooling design temperatures, not the absolute extremes. Outdoor temperatures go past the 0.4% cooling value about 35 hours per year and below the 99% heating value about 88 hours per year.
Manual J 8th edition load calculations use the 1% cooling and 99% heating design temperatures. For ENERGY STAR new homes, the EPA recommends "the ACCA Manual J, 8th edition, 1% cooling season design temperature and 99% heating season design temperature for the weather station that's geographically closest to the home" ( ENERGY STAR, Design Temperature Limits). For the same station the 1% cooling value is exceeded about 88 hours a year, against about 35 for the 0.4% value, so it is the lower of the two, and the table's cooling column is not the Manual J design temperature.
| Metro | County | Zone (IECC 2015) | Winter 99% DB | Summer 0.4% DB | MCWB |
|---|---|---|---|---|---|
| Phoenix | Maricopa County | 2B | 42°F | 110°F | 69°F |
| Tucson | Pima County | 2B | 34°F | 106°F | 66°F |
| Mesa | Maricopa County | 2B | 42°F | 110°F | 69°F |
| Flagstaff | Coconino County | 5B | 10°F | 86°F | 55°F |
Design temperatures are single station values from the ASHRAE 2021 Climatic Design Conditions (99% heating, 0.4% cooling), one airport station per metro, in whole °F within 1°F. DB = dry-bulb. MCWB = mean coincident wet-bulb at the 0.4% cooling design hour.
Zones in this table are from the IECC 2015 county map (PNNL county data). For a ZIP code, BuildSolver's calculator assigns zones by the IECC 2021 county map, which gives the same zones for these counties. A ZIP code near a zone line can get the neighboring zone.
02 · Energy code
Energy code baseline in Arizona is set locally (no statewide residential energy code).
Manual J load-calc documentation requirements come from the code your city or county has adopted; verify your specific AHJ's submittal rules before relying on any baseline.
- Arizona has no statewide residential energy code (DOE Building Energy Codes Program lists it as applicable by county or jurisdiction), so the edition in force depends on the city or county.
- Always confirm with the local building department before assuming any IECC edition applies to a specific job site.
Code status from DOE Building Energy Codes Program - Arizona status, verified October 6, 2026.
03 · Arizona HVAC labor data
BLS wages and employment for HVAC mechanics in Arizona.
These are state-level wages for occupation code 49-9021 - Heating, Air Conditioning, and Refrigeration Mechanics and Installers - from the most recent BLS Occupational Employment and Wage Statistics release.
- Median hourly wage
- $28.56
- Mean annual wage
- $60,900
- Employment estimate
- 10,860
Wage figures from BLS OEWS May 2025, SOC 49-9021 (state-level), released May 15, 2026.
04 · License & permit
HVAC licensing in Arizona runs through AZ ROC.
State-level HVAC contractor licensing is administered by the Arizona Registrar of Contractors. Licenses renew every 2 years.
License types
- R-39 Residential Air Conditioning and Refrigeration
- C-39 Air Conditioning and Refrigeration (commercial)
- CR-39 Dual license (commercial C-39 and residential R-39R scopes)
Permits
Most Arizona cities require a mechanical permit for new HVAC installations and any change-out involving refrigerant lines or electrical service modifications. Permits are issued by city building safety departments.
A replacement install typically requires a permit as well.
Phoenix and Tucson use online permit portals. Pull the permit before purchasing equipment.
05 · FAQ
Common Manual J questions for Arizona contractors.
+How hot does Phoenix get for Manual J sizing?
Phoenix's ASHRAE 0.4% summer DB is 110°F with a 69°F mean coincident wet-bulb - the highest sensible cooling load in any major U.S. metro. Equipment selected with Manual S in Phoenix must verify rated capacity at the 105°F+ outdoor temp, not just AHRI 95°F rating conditions. Manual J 8th edition load calculations use the 1% cooling dry-bulb, which for the same station is at or below the 0.4% value.
+Why does Manual J differ so much between Phoenix and Flagstaff?
Phoenix is zone 2B (hot-dry), Flagstaff is zone 5B (cool-dry) - both in Arizona, both with low humidity, but separated by 5,000 ft of elevation. Flagstaff's heating-dominant Manual J typically delivers 35-40 BTU/hr per square foot in winter; Phoenix's cooling-dominant Manual J runs 25-30 BTU/hr per square foot in summer. The same house design needs a completely different system.
+Which Arizona license covers residential HVAC work?
In the Registrar of Contractors classifications, R-39 is the residential air conditioning and refrigeration license (Ariz. Admin. Code R4-9-103) and C-39 is the commercial one (R4-9-102). CR-39 is the dual license that combines the commercial C-39 and residential R-39R scopes (R4-9-104).
+Why is dry-bulb so much more important than wet-bulb in Arizona?
Arizona's design wet-bulb sits at 66-69°F in the low-desert metros - lower than most of the country despite the high temperatures. The sensible-to-total ratio in Manual J for Phoenix runs 0.85+ (sensible-dominant). Equipment selected on total capacity alone over-cools and short-cycles; selection should target the sensible load.
+Does Arizona require Manual J for permit?
Per jurisdiction. Arizona has no statewide residential energy code, so documentation rules come from the city or county building department. BuildSolver is not ACCA-approved for permit submission. Use its output for sales-phase sizing and client quotes, and produce the permit submittal in ACCA-approved software such as Wrightsoft Right-J8 or Cool Calc Manual J.
+What's the average HVAC technician wage in Arizona?
BLS OEWS May 2025 (released May 15, 2026) reports a $28.56/hr median for Arizona HVAC mechanics and installers, with an annual mean of $60,900. The national median is $29.33/hr.
Try a Arizona load calculation now.
The chat will ask follow-up questions like an experienced engineer - square footage, construction type, window count, insulation level - and run the Manual J on your inputs. Outdoor design conditions come from its own dataset (by IECC 2021 climate zone for a ZIP code, by weather station for the 10 major metros in its city list), not from the metro table on this page.
Start Arizona calculationRelated · same climate zone
Other states with similar ASHRAE climate zones.
Climate-driven Manual J inputs such as infiltration, latent share, and design temperatures behave similarly across states that share a climate zone. Each page below gives that state's own design temperatures and licensing context. Zones combine the IECC 2015 and IECC 2021 county maps.
Data last reviewed October 16, 2026 · underlying sources as of May 15, 2026