What ASHRAE 241 Is Published in June 2023 as Standard 241-2023, Control of Infectious Aerosols, ASHRAE 241 is the first comprehensive consensus standard for managing airborne disease transmission in buildings. It is a voluntary standard given legal force only when adopted by a code authority, written into a project specification or lease, or applied voluntarily […]
Heat Recovery Effectiveness Test Standards
“Effectiveness” is the number every code and rating system quotes, but the value only means something if the test method is stated. This article maps the main heat recovery effectiveness test standards and how they define the metric. Definitions Sensible effectiveness ηs = (Tsupply − Toutdoor) / (Textract − Toutdoor). Enthalpy (total) effectiveness ηt = […]
Pharmaceutical Cleanroom Make-Up Air Heat Recovery: GEP and ASHRAE 90.1 Compliance
Pharmaceutical cleanrooms condition enormous volumes of 100% outdoor air to hold tight temperature, humidity and particulate limits, and that make-up air is the single largest controllable energy drain in a GMP facility. A properly specified air-to-air heat recovery core can hand back 60–75% of the sensible energy in the exhaust before it is thrown away, […]
EU EPBD and Zero-Emission Buildings
The revised Energy Performance of Buildings Directive (EU) 2024/1275 — the EPBD — entered into force on 28 May 2024, with Member States required to transpose it into national law by 29 May 2026. It raises the bar from nearly-zero-energy to zero-emission buildings and makes heat recovery central to compliance. Key Dates Milestone Date Directive […]
EU Ecodesign Requirements for Ventilation Units
The European Union regulates ventilation units through Regulation (EU) 1253/2014 (the “Ecodesign” Lot 21 measure). It sets binding minimum thermal efficiency and fan-power limits for units placed on the EU market, so any AHU or ERV sold in Europe must comply. Scope Applies to residential and non-residential ventilation units with a fan electric power of […]
ASHRAE 62.1 Ventilation and Energy Recovery
ASHRAE 62.1-2022 sets the minimum ventilation rates for acceptable indoor air quality, and its requirements directly drive how much outdoor air — and therefore how much recoverable energy — a system must handle. Energy recovery is the bridge between good ventilation and reasonable energy bills. The Ventilation Rate Procedure Section 6.2 uses the Ventilation Rate […]
ASHRAE 90.1 Heat Recovery Requirements
ASHRAE Standard 90.1 is the reference energy standard for commercial buildings in the United States, and its exhaust-air energy recovery rule is the single most common code trigger for specifying a heat recovery ventilator. This article summarizes the ASHRAE 90.1-2022 requirements that apply to designers specifying air-to-air recovery. When Recovery Is Mandatory (Section 6.5.6.1) A […]