# Presentation: 489235

## Central Air Conditioner Test Procedure Public Workshop

***Central Air Conditioner Test Procedure Public Workshop***

## Question:

***What Parts of the DOE AC&HP Test Procedure and Related CFR Sections Should Be (Re-)Evaluated As Part of a Limited-Scope Proposed Rulemaking?***

## #1: Consider New       Defaults

**Equipment improvements have led to lower tested      ’s.**
**The default       is used less and the two optional tests used to determine       are more frequently conducted.**

***#1: Consider New       Defaults***

**Frequency of Occurrence (%)**

**Measured**

**Data Source:  322 Units Tested by ARI in 2000**

## #1: Changing the       Default

**Pros**
**Reduce testing burden on manufacturers**
**More accurate default values**
**May encourage use of non-bleed TXV’s and time delay relays on the indoor blower**
**Cons**
**May trigger SEER standard adjustment – EPCA 323(e)**

***#1: Changing the       Default***

## #1: Changing the       Default

- Section 323(e) of EPCA states:
- (e) Amendment of standard
- (1) In the case of any amended test procedure which is prescribed pursuant to this section, the Secretary shall determine, in the rulemaking carried out with respect to prescribing such procedure, to what extent, if any, the proposed test procedure would alter the measured energy efficiency, measured energy use, or measured water use of any covered product as determined under the existing test procedure.
- (2) If the Secretary determines that the amended test procedure will alter the measured efficiency or measured use, the Secretary shall amend the applicable energy conservation standard during the rulemaking carried out with respect to such test procedure. In determining the amended energy conservation standard, the Secretary shall measure, pursuant to the amended test procedure, the energy efficiency, energy use, or water use of a representative sample of covered products that minimally comply with the existing standard. The average of such energy efficiency, energy use, or water use levels determined under the amended test procedure shall constitute the amended energy conservation standard for the applicable covered products.
- (3) Models of covered products in use before the date on which the amended energy conservation standard becomes effective (or revisions of such models that come into use after such date and have the same energy efficiency, energy use, or water use characteristics) that comply with the energy conservation standard applicable to such covered products on the day before such date shall be deemed to comply with the amended energy conservation standard.

***#1: Changing the       Default***

## #1: Changing the       Default

***#1: Changing the       Default***

**Difficulties with 323 (e) Standard Amendment:**

**It may be impossible to construct a “representative sample” of products that minimally comply (10 SEER units).  The SEER adjustment could range from zero to roughly 6%, depending on the makeup of the sample.  The statute offers no guidance in constructing the sample.**

## #2: Higher Minimum External Static Requirement for SDHV Systems

***#2: Higher Minimum External Static Requirement for SDHV Systems***

**The forthcoming test procedure final rule includes a definition for a small-duct, high velocity (SDHV) system.**
- “. . . a system that contains a blower and indoor coil combination that is designed for, and produces, at least 1.2 inches (of water) of external static pressure when operated at the certified air volume rate of 220-350 CFM per rated ton of cooling.  When applied in the field, small-duct products use high-velocity room outlets (i.e., generally greater than 1000 fpm) having less than 6.0 square inches of free area.”
**Proposed test procedure change is to specify a higher minimum external static pressure requirement (i.e., 1.2 inches of H****2****O) when testing such units.**
**Proposed change acts to verify that the product is a SDHV system.**

## #3: Optional Testing

***#3: Optional Testing***
*** ******for Two-Capacity Units***

**Forthcoming test procedure final rule does not include the option of testing to determine the cyclic degradation coefficient at high capacity,**** **
**          ****needed in some SEER/HSPF calculations for units that limit low-capacity operation to certain temperature ranges.**
**Propose to permit the option of conducting the extra tests required to determine the cooling and heating mode cyclic degradation coefficients at high capacity.**
**Possible default options:**
**Assign           = Normal      default value (0.25) **
**Assign as:  **

## #4: Frost Accumulation Test at Low Capacity for Two-Capacity Units

***#4: Frost Accumulation Test at Low Capacity for Two-Capacity Units***

**Running a Frost Accumulation Test on a two-capacity heat pump that is operating at low-capacity can be difficult.**
**Often little frosting of the outdoor unit**
**Demand defrost units may not initiate a defrost cycle**
**Possibility of having to run test for 12 hours; hard to achieve test condition tolerances over that long an interval.**
**Options for changing the test procedure:**
**Reduce the 12-hour limit to 6 hours**
**Allow test to end with a manual defrost that is initiated after a manufacturer-specified time interval**
**Develop a default equation**

## #5: (Modulating) Multi-Split Systems

***#5: (Modulating) Multi-Split Systems***

**Two Questions:**
**When testing multi-split systems, should they be allowed to cycle off one or more indoor units for tests at low capacity, minimum speed, or the intermediate speed?**
**Do tests at maximum speed, minimum speed, and the intermediate speed provide a representative performance map from which to determine SEER and HSPF?**
**Presently, multi-evaporator units are tested with all indoor units operating.**** **
**Seek comment on whether and how the DOE test procedure could be changed to better cover multi-split units.**

## #6: Verification of Alternative Rating Methods

***#6: Verification of Alternative Rating Methods***

**Do some smaller manufacturers need an alternative to the presently stated requirement?**
**	****10 CFR, Pt. 430, Subpart B, Section 430.24(m)(6)(iii), “. . .test data for two coils from two different coil families for two different condensing units.  The tested capacities for the matched systems for the two condensing units shall differ by at least a factor of two.”**
**	**If the above _[criteria](slide21.xml)__[ ](slide21.xml)__can not_ be met, can the manufacturer submit data on two indoor units, each tested with two different outdoor units (_[see example](slide22.xml)__)?_** **
**Should manufacturers be able to use a previously tested combination for verification if the indoor coil design has changed?**
**If the new design creates a new **_[coil family](slide23.xml)__?_
**Any limit on age of test data?**

## #7: Test Set-up Requirement for Split Systems

***#7: Test Set-up Requirement for Split Systems***

**Question asked by a user of the DOE test procedure:  Are there any limits on the elevation difference between the indoor and outdoor coils?**** **
**Answer: **
**Follow the  manufacturer installation instructions**
**Nothing presently specified from a laboratory setup standpoint (includes ASHRAE Std 37)**
**Seek Comment:**
**Should some height differential be specified, with the intent of adding test repeatability**
**If yes, what should be the limit?**

## #8: Duct Loss Correction

***#8: Duct Loss Correction***

**A duct loss correction was added in the forthcoming test procedure final rule (Section 3.11).**** **
**The duct loss correction was added so that the DOE test procedure was consistent with industry practice.**
**Unfortunately, the correction is incorrectly applied:  correction for duct losses on the indoor-side is used to correct the secondary measurement of capacity.**
**Plan to change the correction so that duct losses on the indoor side are used to adjust the primary capacity measurement.**

**Note:  The magnitude of the duct loss correction is minimized due to the required duct insulation requirement of R-19 when testing.**

## #9: Sample Calculations

***#9: Sample Calculations***

**Question:  should the DOE central air conditioner and heat pump test procedure reference sample calculations in ASHRAE Standard 116?**** **
**ASHRAE Standard 116, Appendix A**
**Cooling mode examples:  1-speed, 2-speed, variable-speed**
**Heating mode examples:  1-speed, 2-speed, variable-speed**
**Options:**
**Reference Appendix A of Std 116**
**Rather than reference, add sample calculations to the DOE test procedure**
**Do neither – stay as we are**

## #10: Other Suggestions or Comments?

***#10: Other Suggestions or Comments?***

## Code of Federal Regulations (CFR) Other Related Topics?

***Title 10, Part 430***

***The following items will be discussed at the December 13, 2002 Workshop ***_***if time permits***_***.  Written comments on items #1 to #3 are requested.  Item #4 will be discussed at the Workshop if time permits but written comments on this item are not sought. ***

## CFR-Related Topics?

**Other possible updates regarding verification requirements for Alternative Rating Methods (ARMs)?**
**Clarify verification is required for both SEER and HSPF ratings.**
**For companies that sell equipment built by a separate manufacturer, clarify that the former may use the ARM of the Original Equipment Manufacturer (OEM) so long as the ARM is DOE approved.**
**Should the CFR definition for **_[Basic Model ](slide24.xml)_**be revised?**
- 	**Consider definitions from the ARI Operational Manual:**
**Definition for **_[Complete System Manufacturers](slide25.xml)_
**Definition for **_[Coil-Only Manufacturers](slide26.xml)_

## CFR-Related Topics?

**Does the CFR need to be clarified regarding what type of “supporting data” (e.g., 10-minute scans, final summaries) must a manufacturer have on file for tested combinations?**

- Recall that data must be maintained for two years after model is discontinued – 10 CFR, Subpart F, Section 430.62(d)(2).

## CFR-Related Topics?

**ARI Certification Versus DOE Requirements:  Seek to Better Understand Particular Facets**
**DOE certification requirements before initiating sales**
**	****The CFR states [Sec. 430.62( c)] that certification reports on any new models must be submitted to DOE “prior to or concurrent with any distribution of such model.”**
**ARI Certification Program’s 5% tolerance versus the CFR requirements for:**
**The 0.95 divisor used in one of the two algorithms that determines the rated SEER (and HSPF) on a tested model (click **_[here](slide27.xml)__ for CFR text)._
**The 5% tolerance expected of ratings obtained using an alternative rating method (click **_[here](slide28.xml)__ for CFR text)_

## End of Presentation

***HyperLinked Slides Provided Hereafter***

## Present ARM Verification Requirement

**Indoor Unit #1**

**Indoor Unit #3**

**Indoor Unit #4**

**Indoor Unit #2**

**Outdoor Unit “A”**

**Outdoor Unit “B”**

**Note:  Indoor unit #1 (#2) and Indoor unit #3 (#4) can be the same product.**

**Press to Return**

## Alternative ARM Verification Requirement?

**Indoor Unit #2**

**Indoor Unit #1**

**Outdoor Unit “A2”**

**Outdoor Unit “B”**

**Press to Return**

**Outdoor Unit “A1”**

## CFR Definition

**10 CFR, Part 430, Subpart A, Sec. 430.2 “*****Coil family***** means a group of coils with the same basic design features that affect the heat exchanger performance.  These features are the basic configuration, i.e., A-shape, V-shape, slanted or flat top, the heat transfer surfaces on refrigerant and air sides (flat tubes vs. grooved tubes, fin shapes), the tube and fin materials, and the coil circuitry.  When a group of coils has all these features in common, it constitutes a  “coil family.”**

**Press to Return**

## CFR Definition

**10 CFR, Part 430, Subpart A, Sec. 430.2 “*****Basic Model***** means all units of a given type of covered product (or class there-of) manufactured by one manufacturer and . . . (11) With respect to central air conditioners, which have electrical characteristics which are essentially identical and which do not have any differing physical or functional characteristics that affect energy consumption.”**

**Press to Return**

## Definition From the

***ARI Operational Manual***

_**Basic Model Defined for Complete Systems Manufacturers**_**.  Each participant’s listing will be grouped by “basic model”.  For systems where the same outdoor unit is used with several indoor coil combinations (horizontal, vertical, A-coil, etc.), that group constitutes a “basic model”.  “The same outdoor unit” is interpreted as meaning models with the same or comparable compressor, used with the same or comparable outdoor coil surface, and the same or comparable outdoor coil air quantity.**

**Press to Return**

## Definition From the

***ARI Operational Manual***

_**Basic Model Defined for Coil-Only Manufacturers**_**.  A  basic model group consists of either horizontal or vertical configurations for every 6,000 Btu/h size of each configuration.  Thus, if a participant builds both horizontal and vertical indoor coils in 6,000 Btu/h increments from 18,000 to 60,000 Btu/h, it would represent sixteen basic models.**

**Press to Return**

## 10 CFR, Pt. 430, Subpart  B, Section 430.24(m)(1)(ii)

**“****Any represented value of the energy efficiency or other measure of energy consumption of the condenser-evaporator coil combination for which consumers would favor higher values shall be no greater than the lower of (A) the mean of the sample or (B) the lower 90 percent confidence limit of the true mean divided by 0.95.”**

**Press to Return**

## 10 CFR, Pt. 430, Subpart  B, Sections 430.24(m)(3) and 430.24(m)(2)(ii)

- 430.24(m)(3):  “Whenever the representative values of the measures of energy consumption, as determined by the provision of paragraph (m)(2)(ii) of this section, do not agree within five percent of the representative values of the measures of energy consumption as determined by actual testing, the representative values determined by actual testing shall be used to comply with section 323( c) of the Act, or to comply with rules prescribed under section 324 of the Act.

**Press to Return**

- 430.24(m)(2)(ii):  “The representative values of the measures of energy consumption shall be based on an alternative rating method that has been approved by DOE in accordance with the provisions of paragraphs (m)(4) and (m)(5) of this section.