BSR/RESNET/ACCA 310-20xx, draft PDS-02, Standard for Grading the Installation of HVAC Systems Comments Submitted

The following comments have been submitted:

Comment #1

Page Number: 1
Comment Intent: Not an Objection
Comment Type: General

Comment:

RESNET should generate some type of form or spreedsheet a rater can use to complete the recommended testing proceedures.

Comment #2

Page Number: Multiple pages
Paragraph / Figure / Table / Note: Multiple sections
Comment Intent: Objection
Comment Type: Technical

Comment:

I think we can do better than "Observe to be in usable condition". This phrase occurs many times in this document. 

DWYER recommends- TO ZERO GAGE AFTER INSTALLATION Set the indicating pointer exactly on the zero mark, using the external zero adjust screw on the cover at the bottom. Note that the zero check or adjustment can only be made with the high and low pressure taps both open to atmosphere.

This refers to a pressure gauge that is being installed but once you get a new manometer you must check it before use and anytime it has been suspected of being damaged. 

The DG-1000 manual from Minneapolis says: At low pressures, however, the uncertainty will not depend on the manufacturer’s specification since TEC’s practice is to zero the pressure reference at the beginning and end of each gauge calibration.  This is done by applying zero pressure for 1 second, and recording the average of 30 readings during this second.  This average is then subtracted from all readings during calibration.  Therefore uncertainty of the pressure reference at zero pressure depends only on how much the zero value varies during the calibration process.  We assumed that most gauges are used between 54 – 90 °F (12.2 – 32.3 °C), and that they follow TEC’s recommended 2 year interval for calibration.

DG-1000’s, DG-700’s and DG-500’s should be recalibrated every two years to maintain the instruments accuracy specifications of 1% of reading, or 0.15 Pa, whichever is greater. DG-2’s and DG’3 should be recalibrated every year.

TEC used:

1. JCGM 100:2008 Evaluation of measurement data – Guide to the expression of uncertainty in measurement, Joint Committee for Guides in Metrology

Note:  This standard is available as a free download at:  http://www.bipm.org/en/publications/guides/

When we wrote the RESNET standards we worked with the equipment manufacturers and allowed the requirement for Field Calibration Checks. TEC has a section on their website that addresses this. I believe you can adopt this same methodology and wording for any test equipment for HVAC use. FIELD CHECK FOR CALIBRATION.

Field calibration check

In lieu of sending your DG-1000, DG-700 or DG-500 gauge into TEC once every two years for calibration, customers may choose to perform a field calibration check procedure which is contained in the Digital Gauge Field Calibration Check document. This document describes a procedure to field check the calibration of digital gauges against a recently calibrated digital gauge that is being used as an in-house reference standard. We recommend that a field calibration check be performed annually, or whenever a gauge has been dropped or damage is suspected. Results of field calibration checks should be recorded and documented by the customer using the sample log sheets provided at the end of the calibration check document. Gauges that fail the Digital Gauge Field Calibration Check will need to be sent to TEC for recalibration. Note this is for Digital gauges but the same can apply to analog gauges...check it against a reference source or another recently calibrated gauge.

Alnor low flow hoods describe their method as a PERFORMANCE Check.

Performance Check If the calibration is to be checked, the best way is to use a reference flow standard more accurate than the LoFlo Balometer® Capture Hood. Flow standards that may be used for this purpose include orifice plates, venturis, nozzles, and laminar flow elements. These devices require accurate differential pressure, barometric pressure, and temperature reading instruments to measure either actual or standard volume rate. 

Again this points us to a Field or Performance Check...much more than just -"Observe to be usable." I have suggested a modification. 


 

Proposed Change:
  1. 6.7.OEM Static Pressure Table Method
    1. 6.7.1.Equipment Needed. The equipment listed in this section shall have its calibrations checked at the manufacturer’s recommended interval, and at least annually if no time is specified.The equipment listed in this section shall have a observed to be in usable condition. field calibration/Performance check or a zero check any time the measurement unit is new or has been dropped or damage is suspected. In addition, if the manufacturer recommends calibration, then the equipment listed in this section shall be calibrated at the manufacturer’s recommended interval.

 

Comment #3

Page Number: 1
Paragraph / Figure / Table / Note: Purpose, Scope
Comment Intent: Objection
Comment Type: Technical

Comment:

Thank you for considering this comment. We undertstand that the comment is on the sections that have not been revised in this draft. However, we believe this is a significant issue that goes to the core of how the standard will be used and referenced in other documents the future.

It's requested that the purpose and scope statements be modified to (1) clarify the intent and (2) better align with scoping provision in other standards. The purpose and scope statements are critical to determining the applicability of the standard in the building industry and must accurately reflect its intended use. If not corrected, the standard will cause confusion in the market and lead to misapplication in the regulatory arena. 

The purpose statement must include language referencing the grading rules established in the standard – grading is central and integral to the standard. Furthermore, the purpose statement must be clear that the primary intended objective is to support energy ratings of buildings by providing methods and tools to improve accuracy and consistency of the ratings.

Finally, listing the users of the standard in the scope statement is neither a typical standard-writing practice nor appropriate in this context. It’s requested that the sentence be removed. This statement does not serve a functional purpose, but more importantly, it can be misinterpreted as a directive to those listed stakeholders to use the Standard outside of its intended purpose.


 

Proposed Change:

Purpose. This standard establishes the procedures, tolerances, and record keeping practices required to for evaluatinge and grading elements of an HVAC System’s design and installation. This standard is intended to support consistency in energy rating and labeling.

 

Scope. This standard is applicable to Unitary HVAC Systems including air conditioners and heat pumps up to 65 kBtuh and furnaces up to 125 kBtuh in detached one- and two-family Dwellings, Townhouses, as well as in Dwelling Units and Sleeping Units that have their own HVAC system separate from other units. It is intended for use by home energy raters, energy auditors, code officials, or HVAC contractors.


 

Comment #4

Page Number: 18
Paragraph / Figure / Table / Note: 5.1
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

The parties qualified to conduct the testing noted in this and other sections should be more clearly identified.

Proposed Change:

All procedures shall be performed by parties with proper training and a certified HERS Rater, RFI, or third-party certified contractor using appropriate safety equipment. Equipment manufacturers’ operating instructions and safety instructions shall be followed.

Comment #5

Page Number: 21
Paragraph / Figure / Table / Note: 6.2.2
Comment Intent: Not an Objection
Comment Type: Editorial

Comment:

This suggested edit is to clarify the language, ensuring that equipment is operational at the time of inspection.

Proposed Change:

If these components have not yet been installedmade are not operational at the time of inspection, then the Forced-air HVAC System shall not be further evaluated using this standard, and Grade III shall be designated for Blower Fan volumetric airflow, Blower Fan watt draw, and refrigerant chargethe test shall not be conducted.