Serving Oregon since 2020 · 7+ years of experience
ACCA Manual J, S & D Reports in Oregon
ACCA-compliant Manual J load calculations, Manual S equipment selection, and Manual D duct design for Oregon homes and small commercial projects.
Portland · Salem · Eugene · Bend & beyond
HVAC Design for Oregon Building Codes
Oregon builds to its own statewide standard — the Oregon Residential Specialty Code (ORSC), administered by the Building Codes Division — along with the Oregon Energy Efficiency Specialty Code. Like the model codes it's based on, the ORSC requires HVAC equipment to be sized using ACCA Manual S from a Manual J load calculation, which is exactly the documentation we deliver.
Oregon's climate splits sharply at the Cascades. West of the mountains — Portland, Salem, Eugene — is the mild, humid marine Climate Zone 4C, where heating loads dominate and humidity control matters. East of the Cascades — Bend, Redmond — turns colder and drier, landing in Zone 5B and into 6B at elevation. In IECC terms the letter marks moisture: the “C” is marine and the “B” is dry. A load calc tuned to the right side of the state keeps equipment correctly sized and efficient.
From Willamette Valley new construction to high-desert remodels, we produce a complete Manual J, S & D package your local Authority Having Jurisdiction (AHJ) can accept — typically within three business days.
Oregon Climate Zones & County Design Temperatures
West of the Cascades is the mild marine Climate Zone 4C; east of the mountains turns colder and drier into Zone 5B–6B — in IECC terms the “C” marks a marine climate and the “B” a dry one. Design temperatures below are the 1% cooling and 99% heating values for each county, per the ENERGY STAR County-Level Design Temperature Reference Guide (ASHRAE-based).
| County | Cities Served | 1% Cooling | 99% Heating |
|---|---|---|---|
| Multnomah | Portland, Gresham | 88°F | 24°F |
| Washington | Hillsboro, Beaverton | 88°F | 27°F |
| Marion | Salem | 88°F | 26°F |
| Lane | Eugene, Springfield | 88°F | 26°F |
| Jackson | Medford | 96°F | 26°F |
| Deschutes | Bend, Redmond | 90°F | 4°F |
We serve projects statewide — these are just a sample of Oregon counties. We use the recognized design conditions for your specific county and elevation when we run your Manual J.
Oregon HVAC Design FAQ
Does Oregon require a Manual J for a permit?
Oregon builds to the Oregon Residential Specialty Code (ORSC), which requires HVAC equipment to be sized using ACCA Manual S based on a Manual J load calculation. Most Oregon jurisdictions ask for this documentation on residential permit submittals — we provide the complete Manual J, S & D package.
What climate zone is my Oregon project in?
West of the Cascades (Portland, Salem, Eugene) is marine Climate Zone 4C. East of the Cascades (Bend, Redmond) is Zone 5B, reaching 6B at higher elevations. We use the correct design conditions for your specific city.
Will my local building department accept your report?
Yes. We produce a complete, ACCA-compliant Manual J, S & D report formatted for your Authority Having Jurisdiction (AHJ). If your reviewer requests a small change, we handle minor revisions free of charge.
What do you need to get started?
Building plans, insulation and window values, equipment locations, and preferred model numbers. See the full What We Need for a Complete Report checklist.
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Have an Oregon project? Let's talk about working together and answer any questions you have. Send us a note and we'll reach out within 24 hours. Fields marked * are required.
Business hours: Mon–Fri, 7:00 AM – 4:00 PM PT.