Ventilation Load
Practical Engineering Software
LITE BETA
Preliminary Engineer verification required
Tool versionVentilation Load Lite v0.2.0 — BETA
Psychrometric modelASHRAE Hyland–Wexler (1983), water + ice
Properties sourceASHRAE Handbook—Fundamentals Ch 1
Latent methodResidual · Ql = Qt − Qs
Ventilation ratesUser-entered · examples indicative only
StatusPreliminary · reference-informed · engineer verification required
Project Information
Project Name
Client project or zone identifier
Project Number
Drawing or document reference
Engineer
Responsible engineer
Location
Site or city
Zone / AHU Tag
Equipment or zone tag
Date
Calculation date
Remarks
Optional — duty notes, design basis, assumptions
Project metadata for the engineering record — flows into the title block and report header.
02 Air States
OUTDOOR INDOOR ADJUSTED
SETTINGSCalculation Settings
Design mode
Used for load interpretation only.
MODECalculation Method
Direct mode: enter the known outdoor air ventilation airflow directly.
People + area mode: enter occupancy and floor area with user-defined ventilation rates. Rates must be verified against the applicable project code.
ACH mode: enter room volume and air changes per hour. Quick estimate only — may not satisfy ventilation compliance requirements.
OUTDOOROutdoor Air State
Dry-bulb temperature
°C
Relative humidity
%
INDOORIndoor / Return Air State
Dry-bulb temperature
°C
Relative humidity
%
PRESSUREAtmospheric Pressure
Atmospheric pressure
kPa
Altitude override (optional)
m
Overrides pressure when entered
03Ventilation Airflow
DIRECTOutdoor Air Ventilation Rate
Outdoor airflow
L/s
Treated as actual outdoor airflow at the outdoor-air condition (not standard / normalised).
PEOPLE + AREAOccupancy-Based Airflow Estimate
Occupancy
persons
Floor area
m²
Rate per person user-defined
L/s·p
Rate per area user-defined
L/s·m²
Default 0.30 = ASHRAE 62.1 office; AS 1668.2:2024 offices ≥ 0.35 L/s·m². Verify per space type.
Zone-level estimate (Voz = Vbz / Ez). Multi-zone system outdoor air (Vot) and system ventilation efficiency (Ev) are not calculated.
⚠ People and area rates are user-entered. Ventilation rates must be verified against the applicable code, standard, authority, or design basis.
ACHAir Changes per Hour Estimate
Room volume
m³
Air changes per hour
ACH
⚠ ACH-based airflow is a simplified estimate. It may not satisfy ventilation compliance requirements.
04 Ventilation Load Result —
Outdoor Airflow Q̇OA
—
Dry-Air Flow ṁda
—
Sensible Load Qsen
—
Latent Load Qlat
—
Total Load Qtot
—
Moisture Load ṁw
—
Vent. SHR SHR
—
Enthalpy Δ Δh
—
Awaiting inputs
OUTDOOR AIR — W = — h = — v = — — ṁ = — VENTILATION LOAD — Sens — Lat — SHR — — INDOOR / RETURN — W = — h = — ΔW = — ṁ_w = — Δh = — OUTDOOR CONDITION VENTILATION LOAD ESTIMATE INDOOR REFERENCE
05Annual Energy / Heat Recovery
ANNUALAnnual Ventilation Energy
Estimate annual ventilation energy
Hours per day
hrs/day
Days per week
days/wk
Weeks per year
wks/yr
Load factor
%
Plant type
Plant COP
—
Electricity tariff
/kWh
Operating Hrs
—
Effective Hrs
—
Thermal Energy
—
HVAC Input
—
Estimated Annual Cost
—
⚠ Design-point screening estimate — applies the design-condition load across all operating hours and typically overstates true annual energy. Weather profiles, schedules, economiser logic, and seasonal variation are not modelled.
RECOVERYSimple Heat Recovery Adjustment
Include simple heat recovery adjustment
Sensible eff.
%
Latent eff.
%
ERV mode only
ComponentGrossAdjustedReduction
Sensible———
Latent ———
Total———
ℹ Simplified linear effectiveness model. For detailed HRV/ERV analysis use DENOVA Heat Recovery Lite.
Calculation methodology, formulas, and references → Guide · Calculation Methodology
06Report