DRAFT GreenPoint Rated Existing Home Rating Manual version 6.0 | Page 93

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Building Performance and Testing

to outside test. Testing standards shall match the BPI Technical Standards or equivalent. This measure does not require any repair or alteration to the system for credit. If ducts are tightened, credit is available through measure J2, “Energy Upgrades (Elements Only),” or measure J3, “Energy Budget Based on Year”. J6.2. Conduct Flow Hood Test and Assess Delivery of Air for Distributed Systems (1 Point) Home performance testing can assist in evaluating the delivery of air throughout the home. This evaluation should be completed by a home performance contractor or other qualified individual. The tests are used to evaluate the air flow to each room, the size of the return air system, and the location and direction of registers. Complete a flow hood test on all registers and compare the total supply to the total return. Ideally, these should be near 10%. This should include an estimate of the required size of the return flow. Assess the register location and direction of airflow to provide the best mixing and distribution of delivered air. This does not require room-by-room load calculations as is required for an engineered system. The rooms should be balanced based on room size, total supply, and total return. ? ? ? ? ? The return flow can be determined by either: Total Btu / 1000 × 21.7 estimated Using the duct blaster as a powered capture hood as specified in the Energy Conservatory, Duct Blaster Manual , Chapter 13. Using a flow hood that measures return flows Using a flow plate

J6.3. Air Conditioning Compressor Operates Properly and Refrigerant Charge is Optimal (1 Point) Measure the refrigerant charge and, if necessary, increase it to the proper level. This test must be completed by an EPA Certified technician. Testing requirements must be according to BPI Specialist Standards or equivalent. The refrigerant charge may be measured using any of the following methods: ? ? ? ? Sub-cooling method for TXV-equipped systems Superheat method for non-TXV-equipped systems Alternative manufacturer-specific procedures An installed charge indicator

If airflow is changed, the refrigerant charge must be retested. VERIFICATION The Rater will collect reports and documentation of test results from qualified professionals. These tests may be completed by the Rater if he or she is qualified. INTENT To improve energy efficiency and indoor air quality of existing distributed heating and cooling equipment.

GreenPoint Rated Existing Home Rating Manual Version 6.0, September 2013 © Build It Green

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