1609 5TH ST 2020-05-21 - Laserfiche WebLink

EXHAUST SYSTEMS M1507.2 Recirculation of air. Exhaust air from bathrooms M1507.4 Local exhaust rates. Local exhaust systems shall and toilet rooms shall not be recirculated within a residence be designed to have the capacity to exhaust the minimum air or to another dwelling unit and shall be exhausted directly to flow rate determined in accordance with Table M1507.4. the outdoors. Exhaust air from bathrooms and toilet rooms TABLE;M1507.4 shall not discharge into an attic, crawl space or other areas MINIMUM'REQUIRED LOCAL EXHAUST RATES FOR inside the building. ONE-AND TWO-FAMILY DWELLINGS M1507.3 Whole-house mechanical ventilation system. AREA TO BE EXHAUSTED EXHAUST RATES Whole-house mechanical ventilation systems shall be` Kitchens 100 cfm intermittent or 25 cfm Contin- designed in accordance with Sections M1507.3.1 through uous M1507.3.3. Bathrooms Toilet Rooms Mechanical exhaust capacity of 50 cfm M1507.3.1 System design. The whole-house ventilation intermittent or 20 cfm continuous system shall consist of one or more supply or exhaust fans, For SI: 1 cubic foot per minute=0.0004719 m3/s. or a combination of such, and associated ducts and con- trols. Local exhaust or supply fans are permitted to serve as such a system.Outdoor air ducts connected to the return side of an air handler shall be considered to provide supply ventilation. M1507.3.2 System controls. The whole-house mechani- cal ventilation system shall be provided with controls that enable manual override. M1507.3.3 Mechanical ventilation rate. The whole house mechanical ventilation system shall provide outdoor air at a continuous rate of not less than that determined in accordance with Table M1507.3.3(1). Exception: The whole-house mechanical ventilation system is permitted to operate intermittently where the system has controls that enable operation for not less than 25-percent of each 4-hour segment and the ventila- tion rate prescribed in Table M1507.3.3(1)is multiplied by the factor determined in accordance with Table M1507.3.3(2). TABLE M1507.3.3(1) CONTINUOUS WHOLE-HOUSE MECHANICAL VENTILATION SYSTEM AIRFLOW RATE REQUIREMENTS DWELLING UNIT NUMBER OF BEDROOMS FLOOR AREA 0-1 2-3 CO-5 6-7 >7 (square feet) Airflow in CFM <1,500 30 45 60 75 90 1,501—3,000 45 60 ID 90 105 3,001—4,500 60 75 90 105 120 4,501—6,000 75 90 105 120 135 ' 6,001-7,500 90 105 120 135 150 >7,500 105 120 135 150 165 For SI: 1 square foot=0.0929 m2,1 cubic foot per minute=0.0004719 m3/s. TABLE M1507.3.3(2) INTERMITTENT WHOLE-HOUSE MECHANICAL VENTILATION RATE FACTORSa.b RUN-TIME PERCENTAGE IN EACH 4-HOUR SEGMENT 25% 33% 50% 66% 75% 100% Facto? 4, 3 2 1.5 1.3 1.0 a. For ventilation system run time values between those given,the factors are permitted to be determined by interpolation. b. Extrapolation beyond the table is prohibited. "--- ,�j