What Manual S means
Manual S is the ACCA method for picking equipment that matches the Manual J loads, using the maker's performance data at the actual design conditions.
Where it matters on a HVAC job
It is the step that keeps you from rounding up a size just to be safe. When an inspector asks for sizing paperwork, Manual S is the part that ties the load numbers to the model you installed.
What the model code says
- Equipment is sized with ACCA Manual S based on Manual J loads, or other approved methods. (IRC 2021, Chapter 11)
Check which code edition your building department enforces for Manual S before you quote.
What it costs
Koira's heat pump installation cost guide puts a typical job at $6,650, with most between $5,000 to $7,950. The guide shows its sources and what moves the price. The hvac load calculator prices a job line by line.
Work it out
- Free calculator: HVAC load calculator
- Cost guide: Heat pump installation cost
- Licensing: HVAC license rules by state
- Tools, templates and guides: Free HVAC resources
Sources: 2021 International Residential Code, Chapter 11, Energy Efficiency (ICC). Checked October 9, 2026.