2109 MCDOUGALL AVE 2018-01-02 MF Import

8424 September 5, 2006 To: City of Everett Reeardine Fresh Air Supnly for Cobb Residence at 2109 McDougal Ave, Everett: A request was made by City Of Everett to provide fresh air ventilation to the existing South -facing rooms which will not have an exterior will with open -able windows once the planned addition is installed. The air volume for each of the three rooms was calculated as follows: Dining Room (1 P-4" x 12'-8" x 8'- 6"): 1,220 Cu.fl; Kitchen (IT-8" x 8'-8" x 8'-6"): 930 cu.fi.; Utility Room (8'-Q" x T-10" x 8'-6"): 583 cu.11. Total air volume for these three rooms = 2,733 cu.tl. The 2003 International Residential Code, Section R303, specifies all exception where rooms do not need an open -able or ventilated window to outdoors. where opening is not required by Section R310. and an approved mechanical ventilation system is provided capable ol'producing 0.35 air change per hour in the room. Since the rooms in question are not in a Basement and not sleeping rooms. Section R310 does not require them to have an open -able emergency escape and rescue opening. The air volume produced by 0.35 air change per hour for the total volume of 2,733 cu.R. = 956.55 cu.11. Dividing %with 60 minutes per hour gives the required fresh air flow = 956.55/60 = 15.95 CFM (Cubic Feet per Minute). As a part of the addition project, a fresh air intake will be installed on the North -facing half of the existing roof, with a 6" diameter fresh air intake duct with air volume damper connected to the return plenum of the furnace which serves the rooms discussed above. The 6" diameter duct will have a fresh air intake capacity of approxi- mately 95 CFM. The manual air volume damper will be set to reduce intake to'_0 CFM, representing approximately 25% over -capacity. 1 f requested by the City of Everett, a flow measurement of actual air intake flow can be produced at time ol'inspection.