(HVAC) Heating, Ventilation, and Air Conditioning is a major component of the Mechanical aspect of an MEP system, responsible for maintaining indoor environmental comfort and air quality in buildings. The heating system provides warmth during cold conditions using boilers, heaters, or heat pumps. The ventilation system ensures a continuous supply of fresh air while removing stale air, odors, and contaminants. The air conditioning system controls temperature and humidity by cooling and dehumidifying indoor air. In high-rise buildings, HVAC systems typically use a central chilled water system, where chillers produce chilled water that circulates to Air Handling Units (AHUs) and Fan Coil Units (FCUs) to distribute conditioned air across different floors. HVAC systems: *Maintain thermal comfort *Improve indoor air quality *Control humidity *Support smoke control and fire safety *Integrate with electrical and plumbing systems Without HVAC, a building would be uncomfortable, unhealthy,...
ASHRAE 62.2-2025: Comprehensive Overview & Practical Guidance (For Residential IAQ & Ventilation) As homes become more energy-efficient and airtight, ANSI/ASHRAE Standard 62.2-2025 is the go-to benchmark for ensuring acceptable indoor air quality (IAQ) through mechanical ventilation, local exhaust, and source control. This edition (incorporating 16 addenda from the 2022 version) raises the bar for health-focused design. Core Purpose & Scope: 1. Apply to single-family homes, townhouses, and low-rise multifamily dwellings (non-transient occupants). 2. Minimum requirements for dwelling-unit ventilation, local mechanical exhaust, and source control to dilute contaminants from occupants, materials, and activities. 3. Not maximum higher rates are encouraged for better IAQ, especially during pollution episodes or health concerns. Key Updates in 2025 Edition From official ASHRAE sources: 1. Filtration upgrade: Systems with mechanical supply now require MERV 11 filters (up fr...