[BLDG-SIM] ASHRAE 90.1-1989 Power Adjustment Factors

Gowri, Krishnan krishnan.gowri at pnl.gov
Thu Jan 29 17:18:24 PST 2004

Here is the response I got from Eric Richman, 90.1 lighting subcommittee chair,
- krishnan

	-----Original Message----- 
	From: Richman, Eric E 
	Sent: Thu 1/29/2004 4:50 PM 
	To: Gowri, Krishnan 
	Subject: RE: [BLDG-SIM] ASHRAE 90.1-1989 Power Adjustment Factors

	As the current chair of the 90.1 lighting subcommittee, I can offer the following: 
	The power adjustment factors (the factor that uses room dimensions to adjust LPD values up) are based on the calculation method for LPD determination from the old IESNA LEM-1 procedure.  These factors recognize the fact that different space types have different dimensions that will effect the required LPD to light a room.

	The 90.1-1999/2001 standard has done away with these adjustments (primarily for ease of use of the standard) in favor of a standard representative LPD that reflects the commonly expected RCR value for each specific space type.  It was recognized early in the 90.1-1999 development process that specific space types generally had consistent RCR categories within that space type.  The resulting LPDs used in the standard incorporate these typical RCR characteristics.

	Eric E. Richman 
	Pacific Northwest National Laboratory 
	P. O. Box 999  MS K5-16 
	Richland, WA  99352 
	(509) 375-3655 
	(509) 375-3614 (FAX) 

	-----Original Message----- 
	From: Gowri, Krishnan 
	Sent: Thursday, January 29, 2004 10:50 AM 
	To: Richman, Eric E 
	Subject: FW: [BLDG-SIM] ASHRAE 90.1-1989 Power Adjustment Factors 

	Eric:  You may have an answer for this question, - krishnan 

	-----Original Message----- 
	From: Chris Jones [mailto: <mailto:cj at cr-jay.ca> ] 
	Sent: Thursday, January 29, 2004 10:32 AM 
	Subject: [BLDG-SIM] ASHRAE 90.1-1989 Power Adjustment Factors 

	Does anyone know how the ASHRAE 90.1-1989 Lighting Power Adjustment Factors 
	were derived?  See 90.1-1989 6.4.3. 
	Why were they dropped from subsequent versions of 90.1? 

	Chris Jones, P. Eng. 
	14 Oneida Avenue 
	Toronto, ON M5J 2E3 
	Tel. 416 203-7465 
	Fax. 416 203-8249 

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