True Partners Consulting Engineers
truepartners.com.au
Supplementary Cooling & Heating Selection
Supplementary AC Unit Selection
& Load Estimation
Estimates supplementary outside-air ventilation loads, people & equipment gains, filtration requirements, and selects a heat-pump (CHW/HHW) WPAC unit — comparing With and Without filtration cases.
Project & Space
Steps 01 – 04 · Occupancy & outside-air basis
Project
Space
01Occupancy
people
02Area
m²
B/B Occ.
m²/person
B/B O/A
L/s/person
Fitout O/A
L/s/person
03No. PPL over B/B (optional)
Auto = 38.5 people
04B/B O/A check
Ensure 100 L/s O/A via BB system
Design Conditions
Steps 05 – 07 · AIRAH DA09 outdoor & indoor states
05Location
06Space Design Temp
indoor DB at 50% RH
Auto-filled Outdoor / Indoor State
Summer DB 33.0°C / CWB 23.5°C · HR 14.42 g/kg · Winter DB 6.0°C · Indoor 24°C / HR 9.36 g/kg
07Safety Factor
% added to sensible & heating
Internal Loads & Equipment
Steps 08 – 13 · People, electrical, filtration & water
08People Activity
78 W sensible · 52 W latent (per person)
09Electrical Load
W/person
10Additional Electrical
W (fixed)
11Filtration O/A Rate
L/s/person to supp. unit
12Units Selected
with / without filtration
13CHW Flow / Return
°C chilled water
HHW Flow / Return
°C heating hot water
Method: Outdoor & indoor design states per AIRAH DA09 (Edition 4). Ventilation sensible = 1.2·Q·ΔT; latent = 2.97·Q·ΔW. People gains per DA09 activity table. Equipment selection from the Temperzone HWP heat-pump range at 35°C ambient. Results are indicative and do not replace project-specific engineering judgement.
Awaiting Input
Complete the inputs and tap Run Selection
© 2025 True Partners Consulting Engineers · truepartners.com.au · 15 Spottedgum Place, Rouse Hill NSW 2155