ASHRAE Journal - April 2010 - 51

technology award case studies
conservation strategies, including highefficiency chillers, VAV zone control with tracking exhaust, and air volume setback for unoccupied spaces were incorporated into the design. In addition to these traditional measures, three unique measures were included and are discussed in this article. The estimated incremental (additional) cost of these measures was $570,000, of which approximately $400,000 was paid for by the local power utility.
Air Handler Configuration

Since Harborview policy mandates the use of 100% outdoor air systems, multiple supply air handlers were arranged to discharge onto a common manifold. The air handlers are identical for standardization of spare parts and were sized to optimize equipment space use and achieve a low cost-per-cfm. Although five ideally sized air handlers could meet building supply airflow requirements, a sixth was added to reduce energy consumption, provide redundancy and simplify maintenance. Each air handler is equipped with automatic dampers to isolate it from the common manifold when not in operation. Any one unit can be shut off for maintenance and the variable frequency drives for the other five increase output to avoid impacting service to building. Six separate exhaust air handlers with runaround heat recovery coils are manifolded and operated in a similar fashion, providing full redundancy. All exhaust and supply air handlers are connected to a common heat recovery glycol-water piping system. One of the unfortunate side effects of exhaust air heat recovery is the significant increase in fan energy needed to overcome internal pressure drop associated with multirow heat recovery and preheat coils. This higher internal pressure drop would traditionally result in the need for significantly more electrical energy to operate the fan systems. To mitigate this electrical impact, all air handlers are operated, including the redundant units, maintaining the
April	2010	

cfm through each air handler at 83% of capacity. Due to airflow physics, air handler internal pressure drop is reduced as a square of the airflow reduction. After considering the lower airflow and much lower internal pressure drop, one could expect a cube-root reduction of energy. After factoring in a slight reduction of fan, motor and VFD net-efficiency at part load, it was estimated that 83% of the airflow requires 69% of the energy. Even though one extra air handler is operating (20% more air handlers), each is only using 69% of the energy, yielding a 17% net savings.
Multitemperature Distribution Systems

Building at a Glance
Name: Harborview – Norm Maleng Location: Seattle Owner: King County Principal Use: Level 1 Trauma Center Includes: Surgery, recovery, intensive care, airborne infection isolation rooms, specialized clinics and central sterilization/supply Gross Square Footage: 255,000 Substantial Completion/Occupancy: July 2008 Occupancy: 100% National Distinctions/Awards: 2010 ASHRAE Technology Award, Honorable Mention; 2009 Build Washington Award; AGC Award for Public Buildings Over $5 million

As with most hospitals, the Norm Maleng Building uses constant-volume and variable air volume reheat for zone temperature control. Traditionally, air is delivered to internal and perimeter zones at the same temperature. All air is cooled to the temperature required to meet the needs of the zones with the highest air-conditioning load and then reheated as needed to keep all other zones comfortable. Because of the Norm Maleng Building’s high ventilation standard, reheat energy could be significant. To conserve energy, the Norm Maleng Building was constructed with two supply air-distribution systems, one serving only the windowed perimeter zones with minimal internal heat loads (patient rooms, for the most part) and one serving the rest of the process-intensive building having a relatively constant need for cooling. This unique air handler arrangement allows the air for the perimeter zones to

be taken from one end of the manifold, and the air for all other zones taken from the other end. This allows the supply duct riser serving the perimeter zones to provide warmer supply air temperature most of the fall, winter and spring (thanks to Seattle’s famous overcast weather) to minimize reheat. The two air-handling units located close to the perimeter distribution takeoff point provide most of the supply air needed for the perimeter rooms and their discharge temperatures are reset based on

Six Air-Handling Units Perimeter Zones (One-Third Airflow) Interior Zones (Two-Third Airflow)

Figure 1: Supply air-handling unit manifold arrangement. ASHRAE	Journal	 51



ASHRAE Journal - April 2010

Table of Contents for the Digital Edition of ASHRAE Journal - April 2010

ASHRAE Journal - April 2010
Contents
Commentary
Industry News
Letters
Meetings and Shows
Feature Articles
The Science of Evaporation is Key to Defense in Murder Trial
Selecting DOAS Equipment with Reserve Capacity
Technology Award Case Studies: Greening Hospitals
Technology Award Case Studies: Sustainable Remedy for Hospital
Building Sciences
Emerging Technologies
Technical Topics: Selecting Efficient Fans
Technical Topics: Dual-Capacity Heat Pumps
IAQ Applications
International Column
Classified Advertising
Advertisers Index
ASHRAE Journal - April 2010 - Intro
ASHRAE Journal - April 2010 - ASHRAE Journal - April 2010
ASHRAE Journal - April 2010 - Cover2
ASHRAE Journal - April 2010 - 1
ASHRAE Journal - April 2010 - 2
ASHRAE Journal - April 2010 - Contents
ASHRAE Journal - April 2010 - Commentary
ASHRAE Journal - April 2010 - 5
ASHRAE Journal - April 2010 - Industry News
ASHRAE Journal - April 2010 - 7
ASHRAE Journal - April 2010 - 8
ASHRAE Journal - April 2010 - 9
ASHRAE Journal - April 2010 - 10
ASHRAE Journal - April 2010 - 11
ASHRAE Journal - April 2010 - 12
ASHRAE Journal - April 2010 - 13
ASHRAE Journal - April 2010 - 14
ASHRAE Journal - April 2010 - 15
ASHRAE Journal - April 2010 - 16
ASHRAE Journal - April 2010 - 17
ASHRAE Journal - April 2010 - Letters
ASHRAE Journal - April 2010 - 19
ASHRAE Journal - April 2010 - Meetings and Shows
ASHRAE Journal - April 2010 - 21
ASHRAE Journal - April 2010 - The Science of Evaporation is Key to Defense in Murder Trial
ASHRAE Journal - April 2010 - 23
ASHRAE Journal - April 2010 - 24
ASHRAE Journal - April 2010 - 25
ASHRAE Journal - April 2010 - 26
ASHRAE Journal - April 2010 - 27
ASHRAE Journal - April 2010 - 28
ASHRAE Journal - April 2010 - 29
ASHRAE Journal - April 2010 - Selecting DOAS Equipment with Reserve Capacity
ASHRAE Journal - April 2010 - 31
ASHRAE Journal - April 2010 - 32
ASHRAE Journal - April 2010 - BRC1
ASHRAE Journal - April 2010 - BRC2
ASHRAE Journal - April 2010 - 33
ASHRAE Journal - April 2010 - 34
ASHRAE Journal - April 2010 - 35
ASHRAE Journal - April 2010 - 36
ASHRAE Journal - April 2010 - 37
ASHRAE Journal - April 2010 - 38
ASHRAE Journal - April 2010 - 39
ASHRAE Journal - April 2010 - 40
ASHRAE Journal - April 2010 - 41
ASHRAE Journal - April 2010 - Technology Award Case Studies: Greening Hospitals
ASHRAE Journal - April 2010 - 43
ASHRAE Journal - April 2010 - 44
ASHRAE Journal - April 2010 - 45
ASHRAE Journal - April 2010 - 46
ASHRAE Journal - April 2010 - 47
ASHRAE Journal - April 2010 - 48
ASHRAE Journal - April 2010 - 49
ASHRAE Journal - April 2010 - Technology Award Case Studies: Sustainable Remedy for Hospital
ASHRAE Journal - April 2010 - 51
ASHRAE Journal - April 2010 - 52
ASHRAE Journal - April 2010 - 53
ASHRAE Journal - April 2010 - Building Sciences
ASHRAE Journal - April 2010 - 55
ASHRAE Journal - April 2010 - 56
ASHRAE Journal - April 2010 - AP1
ASHRAE Journal - April 2010 - AP2
ASHRAE Journal - April 2010 - AP3
ASHRAE Journal - April 2010 - AP4
ASHRAE Journal - April 2010 - 57
ASHRAE Journal - April 2010 - 58
ASHRAE Journal - April 2010 - 59
ASHRAE Journal - April 2010 - Emerging Technologies
ASHRAE Journal - April 2010 - 61
ASHRAE Journal - April 2010 - 62
ASHRAE Journal - April 2010 - 63
ASHRAE Journal - April 2010 - Technical Topics: Selecting Efficient Fans
ASHRAE Journal - April 2010 - 65
ASHRAE Journal - April 2010 - Technical Topics: Dual-Capacity Heat Pumps
ASHRAE Journal - April 2010 - 67
ASHRAE Journal - April 2010 - 68
ASHRAE Journal - April 2010 - 69
ASHRAE Journal - April 2010 - IAQ Applications
ASHRAE Journal - April 2010 - 71
ASHRAE Journal - April 2010 - 72
ASHRAE Journal - April 2010 - 73
ASHRAE Journal - April 2010 - International Column
ASHRAE Journal - April 2010 - 75
ASHRAE Journal - April 2010 - 76
ASHRAE Journal - April 2010 - 77
ASHRAE Journal - April 2010 - 78
ASHRAE Journal - April 2010 - 79
ASHRAE Journal - April 2010 - 80
ASHRAE Journal - April 2010 - 81
ASHRAE Journal - April 2010 - 82
ASHRAE Journal - April 2010 - 83
ASHRAE Journal - April 2010 - 84
ASHRAE Journal - April 2010 - 85
ASHRAE Journal - April 2010 - Classified Advertising
ASHRAE Journal - April 2010 - 87
ASHRAE Journal - April 2010 - Advertisers Index
ASHRAE Journal - April 2010 - Cover3
ASHRAE Journal - April 2010 - Cover4
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ABEDGD
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201910
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201909
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019septmeber_v2
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019september
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201908
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201907
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201906
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201905
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201904
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019april
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201903
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019march
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201902
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201901
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2019
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018december
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018november
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall_v2
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018october
http://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2018
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201810
http://www.nxtbook.com/nxtbooks/ashrae/ashraeinsights_201806
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201805
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201804
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201803
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201712
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201711
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201710
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall_v2
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201709
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201705
http://www.nxtbook.com/nxtbooks/ashrae/ashrae_meetinginsert_201610
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall_v2
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acrexindia
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer_v2
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer
http://www.nxtbook.com/nxtbooks/amca/2014summer2
http://www.nxtbook.com/nxtbooks/amca/2014summer
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acma_2014summer
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201311
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201309
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acmasupp_2013fall
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201305
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201303
http://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2013winter
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201211
http://www.nxtbook.com/nxtbooks/ashrae/achr_expo_mexico2012
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201209
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v3
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v2
http://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012summer
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201205
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201203
http://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012winter
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201111_v2
http://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201109_v2
http://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2011summer
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201105
http://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201103
http://www.nxtbookMEDIA.com