Michael Raymond To: Brenda Edwards-Jones/EE/DOE@DOE 

# #7

cc: 04/12/2006 11:07AM Subject: Fwd: RE: Re: SDHV test procedure 

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### ----- User Filed as: Not Categorized in ERMS This is a series of email correspondence between Brian Dougherty, NIST, and Craig Messmer, Unico, Oct-Nov, 2003 Michael G. Raymond Project Manager Building Technologies Program Energy Efficiency and Renewable Energy Department of Energy, EE-2J 1000 Independence Ave., SW Washington, DC 20585-0121 phone- (202) 586-9611 fax -(202) 586-4617 Forwarded by Michael Raymond/EE/DOE on 04/12/2006 11:05AM ,- ' "Brian Dougherty' To: michael.raymond@ee.doe.gov 1'- <brian.dougherty@nist.g cc:

ov> Subject: Fwd: RE: Re: SDHV test procedure 04/12/2006 10:18AM 0 Federal Record • Nota Federal Record

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The emails that followed the initial letter forward by Michael E. -- next email. Brian

X-Sieve: CMU Sieve 2.2 Subject: RE: Re: SDHV test procedure Date: Moo, 10 Nov 2003 14:45:36-0600 X-MS-Has-Attach: yes X-MS-TNEF-Correlator: Thread-Topic: Re: SDHV test procedure thread-index: AcOnnVMHdRzwG6ppQe+LQNcSGHnNrQACxhIg From: "Craig Messmer" <craigunicosystem.com> To: "Brian Dougherty' <brian.doughertynist.gov> X-MailScanner: Brian, I suggest we set a maximum size based on velocity (which is based on CFM specified). Our worst case is the smallest unit, where we use a 7 inch duct for 300 CFM. This is a 1 or 1.5 ton unit and delivers 10,000 or 15,000 Btu/hr depending on the condenser match. Of course, there aren t many 1 ton condensers anymore so this is really a 1.5 ton unit. We currently rate the system with 350 CFM and get about 1.3 inches of static with a 7 inch duct. I originally designed it for 6 inch duct but recommend 7 inch in the interest in reducing our inventory of duct sizes, since we already sold the 7 inch, Now that ratings are important, though, I want to keep the 7 inch duct so that I can hopefully find a way to reduce the fan power. This is the most difficult size to met the efficiency requirement.

Do the math, our velocity is 1120 ft/mm. This is the lowest velocity for all our match ups. This matches well with the 2inch duct requirement of 1000 to 2000 ft/mm. The highest velocity is about 2400 ft/mm, which is for the 2.5-ton system with 687.5 CFM and 7inch duct. We are using 250 CFM per nominal ton for AC and 275 for HP.



### ----- I have no idea what Spacepak plans, but I bet they don t have a clue.

Best regards, Craig

Original Message From: Brian Dougherty [mailto:brian,douohertvlnist.qov] Sent: Monday, November 10, 2003 9:14 AM To: Craig Messmer Cc: michael.raymond@ee.doe.gov Subject: RE: Re: SDHV test procedure

Craig, 

# #7

Until your reply, I didn't grasp that the proposed default supply duct sizes are allowed maximums -- that makes more sense. I assume that these maximum values would apply regardless of what is specified by the manufacturer in their installation instructions -right? I will be interested with what Mestek thinks of your numbers but I'm in agreement with the general approach. I question whether anyone would try the oversizing scheme but better safe than sorry. ACEEE will like it because it adds a little to the 'firewall" against non-SDHV units seeking to be so classified in order to be subject to lower NAECA values. Brian
At 08:06 AM 11/10/2003 -0600, you wrote:
Brian, I m not sure I m voicing it properly and maybe I m missing something.

Let me try to explain why the maximum size constraint is a concern. And if no one shares my concern then I can let it go. But if you do share it, then we need some procedure or language that addresses it.

I am concerned that someone could stretch the definition by using a very large duct and making use of the static regain to bump up the external static pressure so that it meets the test requirements while in practice the large duct is never used. For example, if we did this, it would add maybe .2 or .3 to the static pressure measurement. In the ARI database, we have to specify the size of the coil return (minimum area). Similarly, I think we should have to specify the size of the supply duct for SDHV systems.

My default table is meant to keep the spirit of SDHV consistent. Just so no one stretches the definition too badly. Remember we have a velocity range for the small ducts; we should do the same for the main trunk.

We can discuss further if you like.

# #7

----- Best regards, Craig

Original MessageFrom: Brian Dougherty [mailto:brian.douohertvnist.oov] Sent: Thursday, November 06, 2003 3:58 PM To: Craig Messmer Subject: RE: Re: SDHV test procedure

Thanks for the reply. The draft notice of proposed rule presently lists the damper as a recommendation but not a requirement. You may have swayed me with your ETL story. As for the default duct sizes, I still question their value and whether they may cause more harm than good. Unico appears to recommend a specific model of air supply plenum adapter, and thus main supply duct size, for each indoor unit. Please help me understand cases where the default duct sizes would come into play. When are they not discernable from the manufacturers installation instructions? Thanks, Brian At 03:01 PM 11/6/2003 -0600, you wrote:
Brian,

Both Spacepak and Unico have draw-through designs unlike a traditional furnace blower which has a blow-through design. That means the discharge opening of the unit is the size of the blower discharge, not the size of the cabinet (or coil outlet). All SDHV systems are based on small ducts and high velocity supply ducting. Therefore, it is imperative to limit the size of the duct in keeping with the concept of small-duct. In addition, if the supply duct is too large, two things can happen: one, the duct static pressure will be artificially high because of static regain; and two, the higher static pressure will make leaks more likely.

You also stated that the code chamber has to pass a leakage test. This is true, but in my experience the pressure generated by the SDHV equipment is much greater than the design of the code chambers. It is important to reduce the pressure in the code chamber to something reasonable. I once went through three weeks of testing at ETL only to discover that the code chamber was leaking like a sieve and that s why the energy balance was off. If I wasn t there, it would never have been found. Plus, I do not see any negative issues with the damper. Why not mandate it if it improves the accuracy with compromise?

I wrote this in kind of a hurry so if it doesn t make sense let me know. ©

Best regards, Craig

Original MessageFrom: Brian Dougherty [mailto:brian.douphertv@nist.gov]

Sent: Wednesday, November 05, 2003 5:05 PM To: Craig Messmer Cc: michael.raymond@ee.doe.gov; MMcCabe@Navigantconsulting.com Subject: Fwd: Re: SDHV test procedure

Craig, I've had second thoughts on your proposal for default supply duct sizes. I don't think such defaults are needed. The duct size is tied to the flanges on the indoor unit. As per Section 8.6.1 of ASHRAE Std 37-1988, your supply air plenum adapter could be installed if it is listed as a recommended accessory in the Unico installation instruction manual. It appears that Unico only recommends one size adapter for any given indoor unit, right? If you believe the default duct sizes are needed, please reply to let me know why. Thanks, Brian Dougherty

Date: Tue, 04 Nov 2003 14:01:53 -0500 To: "Craig Messmer' <craigunicosystem.com> From: Brian Dougherty <brian.dougherty@nist.gov> Subject: Fwd: Re: SDHV test procedure Cc: MikeDOE, MMcCabe@Navigantconsulting.com Craig, Mike shared your write-up with me. I agree with your point about having internal dampers/restrictors at fully opened given that external static pressure is measured downstream of the outlet. The inclusion of default duct sizes seems reasonable -- although I'm a little worried that a test house may too quickly choose the default value rather than see if the manufacturer's installation instructions provide enough guidance for the duct selection. As for the adjustable damper prior to the airflow measuring apparatus for the purpose of minimizing air leakage, I see it more as an acceptable option than a requirement since limits on air leakage are already covered in the test procedure. Hopefully, the outlet damper box used for cyclic tests could double as the adjustable damper. Unless data would support a change, I would not be inclined to recommend changing the minimum dimension between the coil outlet and the external static pressure taps. One item that I would very much like to hear back from you is the following: will there be any problems with instituting the higher minimum statics for SDHV units at the same time as other test procedure updates, i.e., well before January 2006 when the new NAECA standards become effective? That's the way the proposed rulemaking is being drafted. It makes implementation easier if a small part of the test procedure doesn't have to have an asterisk beside it saying, "Becomes effective on alternative date###." Please reply when you have a chance. Regards, Brian Dougherty, NIST

X-Sieve: CMU Sieve 2.2 Subject: Re: SDHV test procedure To: "Craig Messmer" <craigunicosystem.com> Cc: mike raymond <mike raymondmichael.raymond>, brian.dougherty@nist.gov X-Mailer: Lotus Notes Release 6.0 September 26, 2002From: Michael McCabe <MMcCabeNavigantconsulting.com>

Date: Tue, 4 Nov 2003 10:43:44 -0500 X-MIMETrack: Serialize by Router on WDCIMLSO1/NCI(Release 6.0.2CFflJune 9,2003) at 11/04/2003 10:43:50 AM X-MailScanner: Craig: Per your request for comments, I opened the proposed SDHV revision to the DOE test procedure and have a few questions. These questions are probably due to my lack of familiarity with the current test procedure, but here they are: I) is the standard capacity rating the nominal value for the outside unit (based on the largest selling combination of indoor and outdoor units) or is it the expected rated capacity for the SDHV system? 2) is minimum external resistance the delta p across the discharge duct and flow chamber, i.e., Ps,2-Ps,3? 3)1 don't understand your restrictor plate description. Is this plate on the blower discharge and would not opening it full (per note 5) and running motor at maximum speed (per note 4) create a conflict with minimum static pressure requirements, or is that the purpose of the damper in the discharge duct?? Have you shared these with Ron Graves? Regards, Mike McCabe "Craig Messmer" <craigunicosystem. com>

"Craig Messmer" <craigunicosystem..com>

10/28/2003 04:55 PM

To: Michael McCabe <MMcCabeNavigantconsulting.com> cc: Subject:SDHV test procedure
Mike, We recently had our units tested at ETL as part of the ARI program. The lab did not use the correct airflow because they misunderstood how to test our units. They tested it at lower airflow than we rate it at. This was because they installed our restrictor plate and could not meet the minimum static pressure at our airflow. Therefore, they reduced the airflow till the requirement was met. What they should have done is raise our restrictor plate, or not install it at all. Therefore, I developed the attached test procedure addendum. I have not given it to them yet. I wanted to get your comments first so that it is aligned properly with what the DOE will publish later. Please note that this is the test procedure, not the minimum efficiency. Thanks, Craig Messmer(See attachedjlle: Proposed addendum to API 210-240 to include SDHVsystems.pdj)