| Date |
Text |
| 2014-10-28 09:16:36 | APPROVED WITH EXCEPTIONS. THE TRANSFER DUCT IS REQUIRED |
| | TO BE 14" DIAMETER PER FBC-R M1602.4 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. |
| | 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-THE-WALL 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. |
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