| Date |
Text |
| 2022-07-15 13:54:00 | |
| | SHOW HOW THE RETURN AIR WILL WILL TRAVEL FROM THE ROOMS |
| | WITH THE DOORS BACK TO THE AHU. |
| | |
| | FMC 601.6 BALANCED RETURN AIR. RESTRICTED RETURN AIR |
| | OCCURS IN |
| | BUILDINGS WHEN RETURNS ARE LOCATED IN CENTRAL ZONES AND |
| | CLOSED |
| | INTERIOR DOORS IMPEDE AIR FLOW TO THE RETURN GRILL OR |
| | WHEN CEILING |
| | SPACES ARE USED AS RETURN PLENUMS AND FIRE WALLS |
| | RESTRICT |
| | AIR MOVEMENT FROM ONE PORTION OF THE RETURN PLENUM TO |
| | ANOTHER. PROVISIONS SHALL BE MADE IN BOTH RESIDENTIAL |
| | AND |
| | COMMERCIAL BUILDINGS TO AVOID UNBALANCED AIR FLOWS AND |
| | PRESSURE |
| | DIFFERENTIALS CAUSED BY RESTRICTED RETURN AIR. PRESSURE |
| | DIFFERENTIALS |
| | ACROSS CLOSED DOORS WHERE RETURNS ARE CENTRALLY |
| | LOCATED SHALL BE LIMITED TO 0.01-INCH WC (2.5 PASCALS) |
| | OR LESS. |
| | PRESSURE DIFFERENTIALS ACROSS FIRE WALLS IN CEILING |
| | SPACE PLENUMS |
| | SHALL BE LIMITED TO 0.01-INCH WC (2.5 PASCALS) BY |
| | PROVIDING |
| | AIR DUCT PATHWAYS OR AIR TRANSFER PATHWAYS FROM THE |
| | HIGH PRESSURE ZONE TO THE LOW ZONE. |
| | EXCEPTIONS: |
| | 1. TRANSFER DUCTS MAY ACHIEVE THIS BY INCREASING THE |
| | RETURN TRANSFER 11/2 TIMES THE CROSS SECTIONAL AREA |
| | (SQUARE INCHES) OF THE SUPPLY DUCT ENTERING THE ROOM OR |
| | SPACE IT IS SERVING AND THE DOOR HAVING AT LEAST AN |
| | UNRESTRICTED |
| | 1-INCH UNDERCUT TO ACHIEVE PROPER RETURN AIR |
| | BALANCE. |
| | 2. TRANSFER GRILLES SHALL USE 50 SQUARE INCHES (OF |
| | GRILLE |
| | AREA) TO 100 CFM (OF SUPPLY AIR) FOR SIZING |
| | THROUGH-THEWALL |
| | TRANSFER GRILLES AND USING AN UNRESTRICTED 1-INCH |
| | UNDERCUTTING OF DOORS TO ACHIEVE PROPER RETURN AIR |
| | BALANCE. |
| | 3. HABITABLE ROOMS ONLY SHALL BE REQUIRED TO MEET THESE |
| | REQUIREMENTS FOR PROPER BALANCED RETURN AIR EXCLUDING |
| | BATHROOMS, CLOSETS, STORAGE ROOMS AND LAUNDRY ROOMS, |
| | EXCEPT THAT ALL SUPPLY AIR INTO THE MASTER SUITE SHALL |
| | BE |
| | INCLUDED. |
| | |
| | MICHAEL EDWARDS |
| | MECHANICAL EXAMINER |
| | 401 CLEMATIS STREET |
| | WEST PALM BEACH FL. 33401 |
| | 561-805-6728 |
| | [email protected] |
| | |
