Calculate Appropriate Ventilation Rates and Energy Impacts

Use this calculator to set ventilation rates per current updated guidance based on litres per second per occupant metrics, and convert these to ACH values based on building area and volumes. This calculator will also determine the lost energy as a function of ventilation efficiency and even the component of TEDI that Ventilation represents, and calculate a required aggregate whole-building U-value for compliance with a combined TEDI metric. NOTE: Some PHPP project data will find their projects would fail by entering identical values in this calculator, this is likely because this calculator does not account for the ‘usable gains’ %, and because the calculator is blind to building envelope surface area, orientation, etc. As compensatory measures we have provided sliders to approximate total gains and total air leakage in terms of a heat-loss and gain intensity metric. We do understand that some PH-level projects may fail to meet PHI certification level performance when ventilation rates or occupant schedules are increased, and that is the intended function of this calculator – to demonstrate the sensitive dependence of PHI compliance with low ventilation rates. We are suggesting TEDIventilation limits may need to be increased for the sake of indoor air quality and ventilation adequacy, which may impact TEDI as defined, but that netting zero energy on the basis using TEUI as a governing metric is still readily possible.