Joe_Carrick

Interior Air Quality

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Does anyone use the 4% of habitable area as the minimum operable window opening area as the means of satisfying the code "IAQ" requirement?

Have you been able to get your building official to accept that in lieu of mechanical ventilation?

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I obviously can’t speak for you guys in California and elsewhere, but in Alaska they completely did away with that section of the code (IECC or IRC... I can’t remember which) allowing windows to be considered for code compliance.   Basically our state amendments require mechanical ventilation, there’s no other option.

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Yes it is doable..

 

the California Mechanical Code states that this requirement is regulated by the California Energy Code:

 

FROM THE CALIFORNIA BUILDING ENERGY EFFICIENCY STANDARDS:

 

SECTION 120.1 – REQUIREMENTS FOR VENTILATION Nonresidential, high-rise residential, and hotel/motel buildings shall comply with the requirements of Section 120.1(a) through 120.1(e). (a) General Requirements. 1. All enclosed spaces in a building shall be ventilated in accordance with the requirements of this section and the California Building Code. EXCEPTION to Section 120.1(a)1: Refrigerated warehouses and other spaces or buildings that are not normally used for human occupancy and work. 2. The outdoor air-ventilation rate and air-distribution assumptions made in the design of the ventilating system shall be clearly identified on the plans required by Section 10-103 of Title 24, Part 1. (b) Design Requirements for Minimum Quantities of Outdoor Air. Every space in a building shall be designed to have outdoor air ventilation according to Item 1 or 2 below: 1. Natural ventilation. A. Naturally ventilated spaces shall be permanently open to and within 20 feet of operable wall or roof openings to the outdoors, the openable area of which is not less than 5 percent of the conditioned floor area of the naturally ventilated space. Where openings are covered with louvers or otherwise obstructed, openable area shall be based on the free unobstructed area through the opening. EXCEPTION to Section 120.1(b)1A: Naturally ventilated spaces in high-rise residential dwelling units and hotel/motel guest rooms shall be open to and within 25 feet of operable wall or roof openings to the outdoors. B. The means to open required operable openings shall be readily accessible to building occupants whenever the space is occupied. 2. Mechanical ventilation. Each space that is not naturally ventilated under Item 1 above shall be ventilated with a mechanical system capable of providing an outdoor air rate no less than the larger of: A. The conditioned floor area of the space times the applicable ventilation rate from TABLE 120.1-A; or B. 15 cfm per person times the expected number of occupants. For meeting the requirement in Section 120.1(b)2B for spaces without fixed seating, the expected number of occupants shall be either the expected number specified by the building designer or one half of the maximum occupant load assumed for egress purposes in the CBC, whichever is greater. For spaces with fixed seating, the expected number of occupants shall be determined in accordance with the CBC. EXCEPTION to Section 120.1(b)2: Transfer air. The rate of outdoor air required by Section 120.1(b)2 may be provided with air transferred from other ventilated spaces if: A. None of the spaces from which air is transferred have any unusual sources of indoor air contaminants; and B. The outdoor air that is supplied to all spaces combined, is sufficient to meet the requirements of Section 120.1(b)2 for each space individually. (c) Operation and Control Requirements for Minimum Quantities of Outdoor Air. 1. Times of occupancy. The minimum rate of outdoor air required by Section 120.1(b)2 shall be supplied to each space at all times when the space is usually occupied. EXCEPTION 1 to Section 120.1(c)1: Demand control ventilation. In intermittently occupied spaces that do not have processes or operations that generate dusts, fumes, mists, vapors or gasses and are not provided with local exhaust ventilation (such as indoor operation of internal combustion engines or areas designated for unvented food service preparation), the rate of outdoor air may be reduced if the ventilation system

 

http://www.energy.ca.gov/2015publications/CEC-400-2015-037/CEC-400-2015-037-CMF.pdf

 

 

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Hmm.....

18 minutes ago, Alaskan_Son said:

I obviously can’t speak for you guys in California and elsewhere but in Alaska they completely did away with that section of the code (IECC or IRC... I can’t remember which) allowing windows to be considered for code compliance.   Basically our state amendments require mechanical ventilation, there’s no other option.

I need to check the California Mechanical Code - but I don't have a copy.  If there's anyone out there that has one and can tell me what it says I would appreciate it.

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2 minutes ago, Joe_Carrick said:

Hmm.....

I need to check the California Mechanical Code - but I don't have a copy.  If there's anyone out there that has one and can tell me what it says I would appreciate it.

see what I posted above. California Mechanical Code points to the California Energy Code

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4 minutes ago, Renerabbitt said:

see what I posted above. California Mechanical Code points to the California Energy Code

Thanks Rene.  This is exactly what I needed.

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I haven't even tried that one yet

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6 hours ago, JJohnson said:

the image is from the Mandatory Measures Summary (copy attached)

According to the ASHRAE Standard 62.2 Best Practices Guide (attached), you will have to have both.5aa8b567788e1_VentilationforIndoorAirQuality.thumb.jpg.b573153782fb1c9f72df6e50c0660a4e.jpg

Indoor Venilation Best Practices Guide.PDF

2016_Residential_Mandatory_Measures_Summary.pdf

Thanks.  Not exactly what I wanted to hear but it made me do a little more research so I know what's required.

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On 3/13/2018 at 2:23 PM, Joe_Carrick said:

Hmm.....

I need to check the California Mechanical Code - but I don't have a copy.  If there's anyone out there that has one and can tell me what it says I would appreciate it.

California Codes are all available online. Just Google it.

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