Thermal Comfort, Microclimate & Psychrometric Simulator

Interactive ISO 7730 & ASHRAE 55 evaluation comparing All-Air VAV against Hydronic Radiant + DOAS

ISO 7730 (PMV / PPD) ASHRAE 55 Decoupled Latent Control

Comparative System Scenarios (Select to Benchmark) Click any system to load its operating microclimate

Active

Coupled cooling & dehumidification on a single 6°C coil. Requires cold supply air and higher air speeds, creating draft discomfort.

Ta: 22.0°C Tr: 24.5°C RH: 62% Draft Risk: High

Active

Cooled ceiling/floor surfaces absorb sensible heat silently at 15–16°C water temp while dry DOAS air controls humidity without drafts.

Ta: 24.8°C Tr: 22.0°C RH: 50% ISO Cat. A Comfort

Active

Retrofit solution where radiant panels cannot be installed. Passive heat pipes pre-cool incoming air and reheat supply air for free.

Ta: 23.5°C Tr: 24.0°C RH: 48% Zero Electric Reheat

Operative Temp (Top)
23.4°C
Optimal Comfort Zone

Predicted Mean Vote

-0.09

ISO 7730 Category A

Dissatisfied (PPD)

5.2%

PPD < 6% (Ideal)

Indoor Dew Point

13.7°C

Safe Margin (>2.0 K)

Humidity Ratio (W)

9.8 g/kg

ASHRAE 55 Compliant

Chiller COP Lift
+28% COP
16.0°C High-Temp CHWS

Microclimate Control Variables Live Sliders

Dry-Bulb Air Temperature (Ta) 24.8 °C

Ambient air temperature measured by wall sensor

Mean Radiant Temperature (Tr) 22.0 °C

Weighted surface temperature (cooled ceiling/floor vs facade)

Relative Humidity (RH) 50 %

Controlled via dedicated DOAS dehumidification

Local Air Velocity (Va) 0.08 m/s

Radiant operates silently (<0.10 m/s); VAV diffusers >0.22 m/s

Clothing Insulation (Icl) 0.65 clo

Metabolic Activity (Met) 1.10 met

ASHRAE 55 / ISO 7730 Psychrometric Comfort Chart Click or drag on chart to test air states

Thermodynamic & Comfort Parameter	Calculated Value	Engineering Benchmark / Status
Moist Air Specific Enthalpy (h)	49.8 kJ/kg	Total thermal energy of indoor air
Wet-Bulb Temperature (Twb)	17.8 °C	Adiabatic saturation temperature
Local Draft Risk Rate (DR)	4.2 %	Draft-Free (< 10% ISO Category A)
Recommended Chilled Water Supply (CHWS)	16.0 °C	High-Temp Radiant Mode (+28% Chiller COP)