How the unit works
A combined air handling unit has no built-in cooling or heating source; it uses chilled or hot water to filter, clean, heat, cool, humidify, silence and treat outdoor air. Fresh air mixes with room return air in the mixing section, passes a pre-filter and then a medium filter, is conditioned to the target temperature and humidity, and is finally delivered by the fan section.
Main sections
- Mixed air section with adjustable fresh and return openings (manual, electric or pneumatic).
- Filter section using diamond or four-peak bag media with quick-release frames and alarm indicators.
- Fresh-exhaust section with a primary return damper for proportional mixing or once-through operation.
- Energy recovery section reclaims about 60% of exhaust sensible heat through a plate core without mixing air streams.
- Intermediate service section placed between functional blocks for access and lighting.
- Secondary return section with a top damper, often merged into the supply fan section.
- Cooling coil section built from copper tubes and aluminium fins, fixed or rotary, using steam or hot water.