UFAD System Construction Best Practices: After RAF Installation
UFAD System Construction Best Practices: After RAF Installation
1. Floor Installation and Gaps:
- Install floors consistent with local seismic requirements.
- Minimize gaps between floor panels (approximately 3–4 business cards in width).
- Seal any gaps around the perimeter edge of the floor. Tight gaps can be addressed with carpet and cove molding; larger gaps may require caulking.
2. Air Sealing and Thermostats:
- Verify no air leaks into walls or thermostats. If air aspiration occurs at the thermostat, seal conduits at the floor and use an insulated thermostat sub-base.
- Ensure the floor pressure reference is the occupied space, not the external atmosphere.
- Ensure the underfloor high-pressure reference is not affected by velocity effects.
3. Static and Return Air Management:
- Locate static pressure references in areas free from localized static pressure changes.
- Ensure the return air bypass is used at the AHU or other methods are in place for humidity control.
- Ensure return air paths are clear and maintain a low static pressure loss (e.g., 0.02” wc or less if possible).
- Keep return air velocity at 100 ft/min through ceilings and 200 ft/min through walls.
4. Diffusers and Air valves:
- Leave protective plastic covers on diffusers during construction.
- Orient inlets to air valves away from supply air sources for better acoustic isolation.
- Avoid over-tightening diffuser screws.
5. Sealing and Penetrations:
- Seal holes through the floor for walls built on top of the floor before applying drywall. Perform these seals from the top and enforce quality control.
- Seal around floor boxes that do not self-seal on top of the carpet.
- Minimize penetrations in voice, data, and power boxes. Do not remove unnecessary knockout plates.
6. System Verification and Balancing:
- Balance return air to correct quantities per floor and verify return air static pressure loss during system balancing.
- Remove UFAD fan terminal filters after commissioning the system.
- Verify that the engineer’s operating sequence is followed for all installed equipment.
- Use a temperature reset strategy for core areas under low-load conditions.
7. Design and Construction Coordination:
- If a different design or construction team is responsible for the building shell versus tenant improvements (TI), ensure the mechanical engineer reviews TI plans to identify potential system problems.
8. Owner and Trade Compliance:
- Ensure all trades and the owner follow the established rules and best practices.