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Dave, Apurva

From: VonDemHagen, Rebecca

Sent: Monday, June 10, 2013 4:31 PM

To: riskscicom@aol.com; richard@astrust.com

Cc: Sheppard, Margaret; Newberg, Cindy

Subject: RE: Incompleteness Letter RE: Use of R-443a in Residential Air Conditioning and Heat 

Pump Systems

Mr. Whitmyre and Mr. Maruya, 

Thank you for taking the time to outline your approach. For your response to question 1, please be sure to include both 

the minimum and typical room sizes. We will not be able to provide our formal input until the additional information is 

provided. We look forward to seeing your responses.

Best Regards, 

Rebecca von dem Hagen 

Stratospheric Protection Division 

Office of Atmospheric Programs 

U.S. Environmental Protection Agency 

(202) 343-9445 

vondemhagen.rebecca@epa.gov 

From: riskscicom@aol.com [mailto:riskscicom@aol.com] 

Sent: Tuesday, May 28, 2013 10:41 PM 

To: Newberg, Cindy 

Cc: VonDemHagen, Rebecca; Sheppard, Margaret; richard@astrust.com; engineeringink@earthlink.net 

Subject: Incompleteness Letter RE: Use of R-443a in Residential Air Conditioning and Heat Pump Systems 

Cindy: 

Thank you for your May 15, 2013 letter to Richard Maruya outlining your information needs for the SNAP application 

regarding the use of R-443a in central residential air conditioning systems, residential heat pump systems, and portable 

air conditioning units. As I have been the technical lead on exposure and risk assessment issues, Mr. Maruya has 

authorized me to communicate directly with you to clarify your information needs in this area, so that we may efficiently 

and effectively convey the requested information to you in as short a time frame as possible. Because some of your 

questions ask us to address additional exposure scenarios, wherein we would need to document the specific assumptions 

and parameter values used in the new exposure modeling work, we feel that these questions would best be addressed in 

the form of a supplemental report. 

To clarify our approach to answering the 7 questions posed in your May 15, 2013 letter, I have outlined our approach 

below: 

(1) Charge size. You have asked for typical, minimum, and maximum charge sizes, typical room sizes, and equipment 

capacity. I like the tabular approach that you have suggested, and I will work closely with our team engineer to better 

characterize the ranges of use conditions, to the extent that equipment specifications for representative units are 

available. We have completed bench scale testing of a generic refrigeration system to supplement our tests on actual split 

system residential air conditioning and heat pump systems. The bench scale testing provides a quantitative basis for 

calculating the R-443a charge amount as a percentage of a "full" R-22 charge, which is normally specified on a unit's 

specifications plate. We will document typical room size based on survey data, such as that provided by the National 

Association of Home Builders (NAHB). 
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(2) Risk assessment. In order to answer parts (a), (b), and (c) of your question #2, we propose conducting additional 

indoor air modeling using MCCEM. We propose performing multi-zone modeling to address your subquestion (b). The 

focus of the 3 sub-questions appears to be on furnace room or utility closet scenarios. We will attempt to match room 

volume and ventilation rates to what is normally required by existing building codes for utility closets and furnace rooms, 

to the extent applicable. New fault-tree calculations and diagrams will be developed to address the new scenarios you 

have suggested. Sub-questions (d) and (e) can be simply addressed in a few sentences of text. 

(3) Location of safety valves. We will provide the requested schematics, and will also provide explanatory text. 

(4) Environmental releases and disposal at manufacture. We will work with our engineering team and potential 

manufacturers to elaborate more on the issues you have raised. 

(5) Occupational and consumer exposures. Our current understanding is that the air conditioning and heat pump units will 

be charged and sealed at the equipment manufacturing site. We will attempt to obtain ventilation information and 

requirements for similar types of facilities as a measure of ventilation rates. 

(6) References. We will attach a full copy of the Colbourne 2001 reference to the supplemental report. 

(7) CBI claims. We will provide both a CBI report and a non-CBI redacted report. 

We would kindly appreciate a response from the Agency as soon as possible to indicate its concurrence with our 

proposed approach, or to indicate where alternative approaches, data, or analysis are required. I thank you in advance for 

a timely response. 

Regards, 

Gary Whitmyre, D.A.B.T. 

Whitmyre Research 

2111 Wilson Blvd., Suite 600 

Arlington, Virginia 22201 

(703) 597-9796 

riskscicom@aol.com