ASHRAE 55 and Thermal Comfort ASHRAE 55 defines acceptable thermal environments through the PMV or PPD model, balancing air temperature, mean radiant temperature, humidity, air speed and clothing. Heat recovery changes supply-air conditions, so it must be designed without degrading comfort. Humidity and IEQ Enthalpy recovery transfers moisture as well as heat, helping hold indoor […]
California Title 24 Heat Recovery
California Title 24, Part 6 (the Building Energy Efficiency Standards) is the most aggressive state energy code in the U.S., and its 2022 edition — effective 1 January 2023, with a July 2024 Supplement — puts heat recovery at the center of both nonresidential and multifamily compliance. This article distills the recovery provisions that trigger […]
Heat Recovery Standards and Certifications
When you specify or buy a heat recovery unit, third-party standards tell you the numbers are comparable and real. Knowing the key marks helps avoid inflated claims. Testing Standards AHRI 1060: North American rating method for air-to-air heat exchangers. EN 308: European test method for heat transfer in recovery components. ISO 16494: International method for […]
Building Code Heat Recovery Mandate
Across jurisdictions, building codes increasingly mandate energy recovery once a system serves enough outdoor air. This overview compares the main regimes so a designer can specify one core that clears them all. Minimum Effectiveness by Regime Regime Trigger Minimum recovery ASHRAE 90.1-2022 (US) ≥ 5,000 CFM and ≥ 70% OA 50% enthalpy (AHRI 1060) IECC […]
IECC Energy Recovery Provisions
The International Energy Conservation Code (IECC) is updated on a three-year cycle (2018, 2021, 2024) and is adopted — with or without amendments — by most U.S. states. Its commercial energy-recovery rule lives in Section C403.7, and it is the baseline that many state codes reference. This article summarizes the C403.7 trigger and how the […]
WELL Building Standard Ventilation
The WELL Building Standard v2 (IWBI) is a performance standard for occupant health, and ventilation is one of its strongest levers. Where energy codes set a floor for “acceptable” air, WELL rewards going well beyond it. This article covers the Air Concept features most relevant to recovery and ventilation design. Feature A06 — Enhanced Ventilation […]
RESET Air Standard
RESET Air is the world’s first sensor-based, performance-driven indoor-air-quality certification. Its Commercial Interiors v2.0 standard is about continuous monitoring and transparent reporting, not a one-time design check. This article summarizes the monitored parameters and the targets a space must hold. What Gets Monitored RESET requires continuous monitors covering at least 80% of occupants across all […]
Building Performance Standards Carbon
Building Performance Standards (BPS) are laws that cap a building’s greenhouse-gas emissions and tighten the cap over time, with penalties for exceeding it. The flagship is New York City’s Local Law 97 (LL97) of 2019; this article summarizes how it works and the role of heat recovery in compliance. NYC Local Law 97 — Scope […]
ASHRAE 241: Controlling Infectious Aerosols
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 […]
IECC 2024: Energy Recovery Ventilation Provisions Explained
IECC 2024 and the Energy Recovery Link The 2024 International Energy Conservation Code (IECC) addresses commercial ventilation largely by reference to ASHRAE 62.1-2022. Because 62.1 already requires energy recovery on many large outdoor-air systems, IECC 2024 indirectly tightens ERV expectations, in Climate Zones 4 to 8 an energy recovery ventilator is commonly required where a […]