Subject: Test Sampling Criteria for Multi-family Affordable Housing Units Issue: The referenced standards for the Environmental Tobacco Control Pre-requisite include wording that raises a question about what quantity of units (sampling) are required to be tested (blower door testing) for compliance with the intent of the pre-requisite in a multi-family affordable housing building project. Context: The building consists of twenty affordable housing units: - 1st floor Retail (non-smoking) in addition to (2) units. - 2nd and 3rd floors are similar layouts and contain the remaining 18 units. - This type affordable housing building is one of multiple of this type to be constructed by this non-profit community development corporation. The affordable housing units allow smoking and propose to isolate the distribution of tobacco smoke through attention to the detailing and quality of construction of walls connecting rooms and the corridor. In addition the doors connecting to the corridor will be weather-stripped on three sides with an undercut at the base of the door. Description: The 12/3/2003 CIR under alternative compliance option 2 states "Acceptable sealing of residential units shall be demonstrated by a blower door test conducted in accordance with ASTM standard E779-99 (Determining Air Leakage Rate by Fan Pressurization) using the progressive Sampling Process for Diagnostic Testing in Figure 4-3 of Section 4.4.4 of the California 2001 Title 24 Low Rise Residential Manual - the Home Energy Rating Systems (HERS) Verification Procedure". - Section 4.4.4 states - "The HERS rater shall diagnostically test and field verify the first dwelling unit of each model. To be considered the same model, dwelling units shall be in the same subdivision or multifamily housing development and have the same energy designs and features, including the same floor area and volume, for each dwelling unit, as shown on the CF-1R." In addition the standard describes a sampling one out of every seven (rounded to the next whole number) for each model. - Section 8.1 (which section 4.4.4. references) states - "Each dwelling unit must comply with the Standards when using this approach. When dwelling units have identical conditions the calculations can be combined. This means you will show separate compliance for all unique conditions" The 10/5/2004 Amendment to this CIR expresses that if the doors (connected to common hallways) are not weather-stripped, additional testing is required in the corridor. The pressure difference shall be measured and recorded at least once every 10 seconds for at least 15 minutes; the average recorded pressure difference shall be no less than 5 Pa (0.02 inches of water gauge), with the lowest recorded pressure difference no less than 1 Pa (0.004 inches of water). Proposed Approach: The proposed approach based on our understanding of the criteria is: - Sampling - (3) blower door tests will be conducted following the outlined criteria for the 20 units (rounded up to the next whole number). - If test results do not meet acceptable levels, additional tests will be conducted in accordance with the referenced process procedure. - Weather-stripping is being installed at all edges of connecting doors (except at the undercut at the door sill), and we therefore assume the testing referred to in the 10/5/2004 Amendment is not required.
The sampling appears to be in compliance with the requirements established in the California 2001 Title 24 Low Rise Residential Manual - the Home Energy Rating Systems (HERS) Verification Procedure. This procedure must be clearly detailed in the project\'s application for the reviewer to understand. It is also reasonable to expect additional tests, in accordance with the referenced standard, should the results prove unsatisfactory. The requirement for weather stripping does not specifically preclude the sill from this requirement and therefore will be necessary. It is consistent throughout the contents of both alternative compliance paths and in the original credit requirement that openings in ceiling, walls, and floors must be sealed and it is consistently required that a minimum pressure differential must be maintained to achieve this credit, in the absence of weather stripping. Therefore, in this case it is not acceptable to preclude the weather stripping at the sill of the doors, unless the connecting hall is tested and proves to maintain the required positive pressure as listed in CIR 10/05/04.