Document ID: EPA-HQ-OAR-2016-0130-0015
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2020-07-16T04:00Z

TO:  ASTM E06.54 Members and All Other Interested Parties
FROM:  Bob Ferguson
DATE:  January 6, 2020
RE:  December 17, 2019 Teleconference Call Report - ASTM E2515 and ASTM E3053 Task Groups

Task Group teleconferences for both ASTM E2515 and E3053 Task Groups were held via WEBEX on December 17, 2019.  These task groups are addressing possible revisions/updates to these two ASTM standard test methods.  Once again, the calls were combined for convenience of the participants.  Future calls will operate separately and may or may not on occur in the same consecutive fashion.  That will be determined by the task group participants.
There was a brief discussion about the ASTM Collaboration Areas.  Bob Ferguson will send out an inquiry to all interested parties to determine who is interested in having access to the CA's.  Please return the information to Bob as soon as possible. These will be established soon, and non-ASTM members who have indicated they want access will receive an e-mail invitation.
The attendees list was confirmed and is included with this report.  I have added columns indicating ASTM membership status and whether I have received a request for access to the CA's.  Please point out any errors or omissions.
ASTM E2515:  Standard Test Method for Determination of Particulate Matter Emissions Collected by a Dilution Tunnel

Bob Ferguson opened the discussion on items previously identified as requiring the attention of the task group.  These are being addressed in the order they appear in the test method except when topics are intermingled between various sections.

 Sample Flow (and Filter Size)
 Currently, ASTM E2515 specifies the use of 47 mm filters only.  That restricts the maximum sample flow rate (based on not exceeding filter face velocity guidelines). Allowing only one filter size was done to eliminate differences in filter trains between labs and to try to minimize the added uncertainty associated with the additional weighings that are needed when solvent recovery is used instead of direct component weight determinations.  However, EPA already allows other filter sizes.  And, bigger filters do allow higher sample flow rates.  This may become important as sample catches decrease with cleaner burning appliances and as dilution tunnel flow rates increase.  This issue and its associated elements will require careful consideration by the group, including full understanding of the impact on variability in test results.
 Dryer Exit Temperature
 It was proposed to lower the Dryer exit temperature from the currently specified 80°F to 68°F for consistency with other test methods (including EPA Method 5).  There was some concern expressed when testing on hot days (that the lower temperature would require air conditioning).  And, since the dry gas meter temperature is recorded and used to correct sample flow to standard conditions, the question is  -  what is the real impact, if any? Data was requested to see how often the dryer exit temperature exceeds 68°F during a range of test facility conditions.  The current EPA requirement to maintain the filter temperature between 80 and 90°F (for room heater cordwood testing) was also raised during the discussion in terms of impact on dryer outlet temperature. Again, data would be helpful.

 Filter Material and Filter Size (See earlier Sample Flow discussion)
 There was a discussion about switching the current glass fiber filter material requirement to PTFE-bonded borosilicate glass fiber material.  This is currently an EPA-imposed requirement when testing room heaters using the ASTM cordwood test method.  A question of equivalency (i.e.., is it changing the PM we are catching?) was raised by Bob Ferguson in the context of supporting the rationale for changing material after decades of testing with glass fiber filters.  No comparison data has been published that he is aware of.  If that data is published, it should be made available to the TG.  One of the reasons given by Stef Johnson for the switch is to minimize the loss of filter material due to sticking.  That may be adequate justification by itself.  Russ McBrien and Sebastian Button supported switching since they are already using the EPA specified PTFE-bonded filters.  Text to be revised is shown below.
                  7.1.1 Filters -- Glass fiber filters PTFE-bonded borosilicate glass fiber filters with a diameter of 47 mm
                  without organic binder, exhibiting at least 99.95 % efficiency
            (<0.05 % penetration) on 0.3-micron dioctyl phthalate smoke
            particles in accordance with Practice D2986. Manufacturer's
            quality control test data are sufficient for validation of efficiency. 8
            
            8 Gelman A/E 61631 and Whatman 1841-047 filters have been found acceptable
                  for this purpose. Pall Type Pallflex EMFAB TX40HI20 WW filters have been found acceptable for this purpose.
                  If you are aware of alternative suppliers, please provide this
            information to ASTM International Headquarters. Your comments will receive
            careful consideration at a meeting of the responsible technical committee,1 which
            you may attend.
            
 Dilution Tunnel Flow Determination and Limits
 There was some initial discussion regarding dilution tunnel flow rates and specifically on the impact on condensation in the filter holders, especially under some cordwood testing conditions.  A lot of moisture is generated during cold starts and the initial portion of high fire testing.  Moisture condensation has been observed, even when filter temperatures are maintained at the EPA specified range of 80-90°F.  Current E2515 wording limits the maximum tunnel flow to five times the minimum flow required to capture all smoke exiting the appliance.   Increasing the tunnel flowrate above that current limit can help mitigate condensation issues.  However, increasing tunnel flow rate also reduces PM concentration and therefore, PM filter catch.  Maximizing sample flow rates can offset some of the impact but filter catch impacts on uncertainty will continue as tested products become cleaner and cleaner.  Bob Ferguson raised the idea that at some point there will have to be a lower detectable limit as there are with many other measurements.  Rick Curkeet discussed ways to reduce the chance of condensation including lowering lab humidity during high humidity periods or increasing the allowable filter temperature. All the inter-relationships between parameters need full consideration in order to avoid unintended consequences.  Bob Ferguson asked for help in locating a study on the impacts that dilution tunnel flow rates have on PM capture that was conducted many years ago by Dr. Houck while he was at OMNI.  Efforts to locate the paper have been unsuccessful so far.

 Pitot Tube Leak Testing
 This equipment issue (which digital manometers may remedy) was raised by Ben Myren and will be discussed in a future call.
            
 Proportional Rate
 EPA has tightened the requirements for maintaining proportionality between tunnel flow and sample flow.  Current E2515 requires that no more than 10% of PR values can be outside the 90-100% range and none outside 80-120%.  EPA room heater cordwood testing requirements allow only one value to be outside the 90-110% range.  Gaétan Piedalue expressed concern about how difficult this can be when cold starts are included in the testing or when the load door is open during testing.  A request for data was made (i.e., data on PR values and how often the PR value is outside these ranges).  It should be relatively easy to look at datasets and track the variations in PR.  Stef Johnson asked that anyone with concerns or information on this matter contact him directly.

These topics will remain active as we start to consider other identified issues in future meetings including (but not limited to):

 Filter Temperature (discussed briefly in terms of condensation)
 Filter and Probe Desiccation
 Filter and Probe Weighing
 Sample Train Leak Testing When Filter Changes are Required or Needed
 How Low Filter Catches are Currently Addressed
 Test Method Precision
 Tunnel Temp/RH/Dew Point
 Condensation in Filter Trains
 Low Filter Catch / Lower Detectable Limit
 TEOM

   The date and time for the next call two calls was discussed.  The decision was to continue to hold the calls in conjunction with the E3053 calls but with a 30-minute break between sessions.  
   
   The next call will be on January 28[th] at 1:30 PM EST.  The February call will be on February 18[th], again at 1:30 PM ET.  Please put these on your calendars. 
   
   There will also be a face-to-face meeting at the HPBA EXPO in New Orleans.  This meeting will be on Tuesday, March 10[th].  The meeting will be held later in the afternoon to allow folks to arrive on the same day.  The specifics (time and location) will be provided as soon as they are finalized.  Call-in details will also be provided for those that can't be there in person.  
   
   At 3:00 PM EST the E2515 portion of call was adjourned.
   
   ASTM E3053:  Standard Test Method for Particulate Matter Emissions from Wood Heaters Using Cordwood Test Fuel

   Discussion began on the topics/Issues identified so far.  
   
       Manufacturer's Written Instructions/Owner's Manual
             The initial question is whether the current E3053 language specific enough.  Are limits needed should on what can be done?  Is more specificity needed on how the manufacturer's written instruction to the labs for test purposes must be tied to owner's manuals?  Russ McBrien from Travis felt that non-cat tube stoves, cat stoves and hybrid stoves all need good instructions-that are followed-to achieve repeatable results. He feels that all cat stoves are pretty forgiving regarding how you load the fuel load, but that loading instructions are critical to success of tube stoves.   He suggested making stricter requirements on manufacturers for what's in the owner's manual. Right now, there are examples of a lack of connection between test instructions given to the lab and owner's manual language where instructions are too general and not detailed enough to reflect optimum fuel loading.  Bob Ferguson suggested that the intent has always been that the owner's manual should give instructions to the user for optimizing performance. But it's more of a regulatory issue since it can require judgment and therefore, an ultimate decision maker. Perhaps better EPA guidelines for the labs and for owner's manual content are needed as a starting point.  Stef Johnson has recently had discussions with test labs about some manufacturer specified fuel loading procedures.   From his perspective, it comes down to reasonableness. That is, are instructions in owners' manual reasonable?  If the consumer is likely to operate the stove as instructed in the manual, then that's fine.  But if the instructions that go to lab are not the way a typical consumer is likely to do it, then that doesn't pass sniff test. An example is that shaving bark off is something consumers would not typically do. Bob Ferguson opined that "reasonable" is a really squishy term.  Stef agreed. Bob suggested coming up with a list of what's not reasonable as a beginning point for future discussion
               
       Overall Test Method Concept
          Current E3053 requirements include low, medium, high fire test runs with PM measured for each discreet run.   In one day, it is possible to conduct a high fire test run (including cold start) followed by a low or medium fire test run, but not all three.  A medium is not allowed to be run prior to a low fire test due to the current requirements for running a high fire cycle to establish a charcoal bed before the test run.  This means that E3053 typically can be done in two days (High and Low on Day 1, High and Medium on Day 2).  At the time, E3053 needed to bridge the gap between M28 (crib) and E2780 (crib with cordwood annex). There was strong resistance to moving too far away from the old test protocols and for continuing to determine PM emissions from individual burn rate/heat output categories, especially within the regulatory community and with some manufacturers. Now stakeholder attitudes have changed.  The Integrated Duty Cycle (IDC) test protocol, currently under development by for room heaters by NESCAUM/NYSERDA, is trying to achieve a single day test protocol with a single number emission rating that covers the full operating range of the tested heater. A one-day test should allow replicate testing at a reasonable cost.  Some variability can be mitigated by averaging the results from multiple tests.  Russ McBrien, in his written comment, wants the task group to consider what is a reasonable workday (not 10 to 20 hours).  Extra-long test days are a personnel and financial burden.  Any test method will need to demonstrate a high correlation between lab results and real-world emission performance. Now that E3053 is being widely used, the warts and shortcomings are being revealed.  This shouldn't be surprising.  This task Group's primary objective should be to move toward what is most predictive of real-world PM performance. Let's keep all options on the table until we can understand the best path forward.
 
       Pre-conditioning Requirements
 Bob Ferguson raised the issue that the current E3053 doesn't specify how to determine that 50 hours of preconditioning have been reached.  Flue gas temperature must be recorded but there is no lower cut-off.  It was mentioned that the reality is that the 50 hours is a formality because these test stoves have been operated extensively prior to certification testing and will have accumulated far more than 50 hours of operation.  It was suggested that the group leave this matter alone for now, as there are more pressing issues.
         
       Test Fuel Load Requirements
          There was limited discussion on this topic due to time constraints.  There was discussion about kindling moisture and the current wording in E3053.  Rick Curkeet mentioned the existence of research regarding woody material drying time (e.g., grass takes ~1 hour to dry, while wood plants can take 24 to 60 hours) and how guidelines might be developed for drying kindling, in lieu of measurements. Ben Myren said his objective was to reduce variability by requiring everyone do fuel-related procedures the same way, including piece size and moisture determination.  There is some sense that the current wording in this section allows too much flexibility.  This issue will likely consume significant TG time as we move forward.

These topics will remain active as we start to consider other identified issues in future meetings including (but not limited to):

       Test Fuel Properties
       Test Requirements
       Equations
   
   The next call will be on January 28[th] at 3:00 PM EST.  The February call will be on February 18[th], again at 3:00 PM ET.  Please put these on your calendars. 
   
   E3053 will be on the agenda at the March 10[th] meeting at the HPBA EXPO in New Orleans.