Definition:
Balanced ventilation is an HVAC system that uses two separate air streams to simultaneously supply fresh air and exhaust stale air from a building at equal rates. This method ensures optimal indoor air quality by controlling both incoming and outgoing air flow, while also allowing for energy recovery between the two air streams, thus improving overall system efficiency.
Additional Facts
- Heat Recovery: Balanced ventilation systems with heat recovery can reclaim up to 85% of the energy from exhaust air, significantly improving overall HVAC efficiency.
- Indoor Air Quality: These systems provide continuous fresh air while removing stale air, effectively reducing indoor pollutants and maintaining optimal humidity levels.
- Pressure Balance: By simultaneously supplying and exhausting equal amounts of air, balanced ventilation systems prevent pressure imbalances that can lead to drafts or moisture issues.
- Energy Code Compliance: Many modern building codes now require balanced ventilation systems to meet stricter energy efficiency and indoor air quality standards.
- Zonal Control: Advanced balanced ventilation systems can offer room-by-room airflow control, allowing for customized comfort and efficiency in different areas of a building.
Fundamental Mechanisms
| Mechanism | Purpose | Key Components | Critical Issue | Impact of Failure |
|---|---|---|---|---|
| Heat Recovery Ventilator (HRV) | Transfers heat from exhaust air to incoming fresh air | Heat exchanger core, fans, filters, ductwork | Clogged filters, frozen core | Reduced efficiency, increased energy consumption |
| Energy Recovery Ventilator (ERV) | Transfers heat and moisture between airstreams | Enthalpy wheel, fans, filters, ductwork | Wheel contamination, motor failure | Poor indoor air quality, inefficient moisture control |
| Demand-Controlled Ventilation (DCV) | Adjusts ventilation rates based on occupancy | CO2 sensors, dampers, control system | Sensor calibration drift, damper malfunction | Over/under ventilation, energy waste |
| Air Distribution System | Delivers fresh air and removes stale air | Ducts, grilles, diffusers, dampers | Air leaks, improper balancing | Uneven air distribution, reduced comfort |
| Filtration System | Removes contaminants from air streams | HEPA filters, pre-filters, filter housing | Filter saturation, bypass leakage | Decreased air quality, increased system resistance |