StandardRecommended
Design HVAC for 69-80°F comfort range, 30-65% relative humidity
NKBA 4th ed §4.5 Human Comfort ZoneDescription
Heating and cooling systems should maintain the comfortable air-temperature range of 69-80°F (21-27°C) and 30-65% relative humidity. The wider tolerable range is 60-85°F at 20-70% RH. Air-movement design should target 50-200 ft/min within occupied zones.
Why this exists
Sustained operation outside these envelopes causes user discomfort and increases mechanical-system runtime. The narrower comfortable range is the design target; the tolerable range is what the system must still hold during peak load.
Measurements
| Property | Operator | Value | Unit | Note |
|---|---|---|---|---|
tempComfortableLow | min | 69 | °F | Comfortable low |
tempComfortableHigh | max | 80 | °F | Comfortable high |
rhComfortableLow | min | 30 | % | Relative-humidity low |
rhComfortableHigh | max | 65 | % | Relative-humidity high |
Categories
EnergyVentilation
Source
NKBAno manifest entry
Kitchen & Bath Planning Guidelines with Support Spaces and Accessibility, 4th Edition (via 2023 Design Competition Guidelines summary) (4th ed (2022))
Section: 4.5 Human Comfort Zone
Published 2022-01-01 · last verified 2026-05-14
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Avoid VOC-containing materials; specify low-VOC finishes · NKBA 4th ed §4.4 Material & Finish Planning
- All ventilation equipment must exhaust to the exterior of the building envelope · NKBA 4th ed §8.1 Ventilation Planning
Last reviewed 2026-05-14.