ASHRAE Journal -November 2012 - 18
Methods for Effective Room Air Distribution
Part One
A
By Dan Int-Hout, Fellow ASHRAE
rchitects and owners desiring LEED certification for their buildings are challenging engineers to design HVAC systems that are at
least 30% better than the base system in ASHRAE/IES Standard 90.12010, Energy Standard for New Buildings Except Low-Rise Residential Buildings. There is talk of raising the bar to 40% or even 50%.
In addition, Standard 90.1-2010 lowered the maximum energy use of the base system, which is overhead delivery of VAV controlled air. Improving on this base system is a real challenge. The requirements in ASHRAE/USGBC/ IES Standard 189-2011, Standard for the Design of High-Performance Green Buildings Except Low Rise Residential Buildings, are similarly challenging for designers. As a result, some architects are considering alternate means of air delivery as they assume one cannot meet the requirements with a variable air volume (VAV) system. These alternates include underfloor air distribution, displacement ventilation and chilled beams
18 ASHRAE Journal
(low inlet pressure ceiling induction devices). However, the energy calculation programs used to predict the energy use of these systems are largely unverified, at least in the form of available published data. Overhead VAV (which includes fan-powered terminals) has been in widespread use in North America for more than 40 years, and the energy use calculations have been well vetted. (Note that ASHRAE Research Project 1292 suggests the leakage of parallel fan-powered terminals has likely been underestimated in the effect on energy use.) The validation has to account for long-term weather variations involving the continually updated bin data for
ashrae.org
most of North America, as well as many locations worldwide. The newer systems haven’t been in use long enough (at least in North America) to have a robust volume of data to measure the accuracy of energy use (or savings) predictions. Engineers, therefore, use best known data. The result is that a great deal of creativity is possible in establishing performance parameters, and no one can prove them wrong. Moreover, while we have been designing with overhead VAV for more than 40 years, BOMA reports that a big reason tenants fail to renew a lease is occupant dissatisfaction with the thermal environment. So we are moving into new territories of air distribution, but we apparently still don’t know how to properly design or apply the method with which we have the most experience. Part One of this article discusses essential requirements (in standards, guidelines and rating systems) that cover thermal comfort, acoustics and ventiAbout the Author
Dan Int-Hout is a chief engineer at Krueger in Richardson, Texas.
November 2012
ASHRAE Journal -November 2012
Table of Contents for the Digital Edition of ASHRAE Journal -November 2012
ASHRAE Journal -November 2012
Contents
Commentary
Industry News
Letters
Meetings and Shows
Feature Articles
Methods for Effective Room Air Distribution: Part One
Technology Award Case Studies:
TES for Medical Center
Feature Articles
Demand-Controlled Ventilation for Commercial Kitchens
Special Supplement: BACnet® Today and the Smart Grid
Commentary
BACnet for a City
Electric Utilities and the HVAC Industry
OpenADR Advances
Demand Response and Light Control
Standing Columns
Building Sciences
Special Section
InfoCenter
Data Centers
Emerging Technologies
Refrigeration Applications
Engineer's Notebook
Special Products
Washington Report
Products
Classified Advertising
Advertisers Index
ASHRAE Journal -November 2012 - ASHRAE Journal -November 2012
ASHRAE Journal -November 2012 - Cover2
ASHRAE Journal -November 2012 - 1
ASHRAE Journal -November 2012 - 2
ASHRAE Journal -November 2012 - Contents
ASHRAE Journal -November 2012 - Commentary
ASHRAE Journal -November 2012 - 5
ASHRAE Journal -November 2012 - Industry News
ASHRAE Journal -November 2012 - 7
ASHRAE Journal -November 2012 - 8
ASHRAE Journal -November 2012 - 9
ASHRAE Journal -November 2012 - 10
ASHRAE Journal -November 2012 - 11
ASHRAE Journal -November 2012 - Letters
ASHRAE Journal -November 2012 - 13
ASHRAE Journal -November 2012 - Meetings and Shows
ASHRAE Journal -November 2012 - 15
ASHRAE Journal -November 2012 - 16
ASHRAE Journal -November 2012 - 17
ASHRAE Journal -November 2012 - Methods for Effective Room Air Distribution: Part One
ASHRAE Journal -November 2012 - 19
ASHRAE Journal -November 2012 - 20
ASHRAE Journal -November 2012 - 21
ASHRAE Journal -November 2012 - 22
ASHRAE Journal -November 2012 - 23
ASHRAE Journal -November 2012 - 24
ASHRAE Journal -November 2012 - 25
ASHRAE Journal -November 2012 - 26
ASHRAE Journal -November 2012 - 27
ASHRAE Journal -November 2012 - TES for Medical Center
ASHRAE Journal -November 2012 - 29
ASHRAE Journal -November 2012 - 30
ASHRAE Journal -November 2012 - 31
ASHRAE Journal -November 2012 - 32
ASHRAE Journal -November 2012 - 33
ASHRAE Journal -November 2012 - 34
ASHRAE Journal -November 2012 - 35
ASHRAE Journal -November 2012 - Demand-Controlled Ventilation for Commercial Kitchens
ASHRAE Journal -November 2012 - 37
ASHRAE Journal -November 2012 - 38
ASHRAE Journal -November 2012 - 39
ASHRAE Journal -November 2012 - 40
ASHRAE Journal -November 2012 - 41
ASHRAE Journal -November 2012 - 42
ASHRAE Journal -November 2012 - 43
ASHRAE Journal -November 2012 - 44
ASHRAE Journal -November 2012 - 45
ASHRAE Journal -November 2012 - 46
ASHRAE Journal -November 2012 - 47
ASHRAE Journal -November 2012 - 48
ASHRAE Journal -November 2012 - Special Supplement: BACnet® Today and the Smart Grid
ASHRAE Journal -November 2012 - B2
ASHRAE Journal -November 2012 - Commentary
ASHRAE Journal -November 2012 - BACnet for a City
ASHRAE Journal -November 2012 - B5
ASHRAE Journal -November 2012 - B6
ASHRAE Journal -November 2012 - B7
ASHRAE Journal -November 2012 - B8
ASHRAE Journal -November 2012 - B9
ASHRAE Journal -November 2012 - Electric Utilities and the HVAC Industry
ASHRAE Journal -November 2012 - B11
ASHRAE Journal -November 2012 - B12
ASHRAE Journal -November 2012 - B13
ASHRAE Journal -November 2012 - B14
ASHRAE Journal -November 2012 - B15
ASHRAE Journal -November 2012 - OpenADR Advances
ASHRAE Journal -November 2012 - B17
ASHRAE Journal -November 2012 - B18
ASHRAE Journal -November 2012 - B19
ASHRAE Journal -November 2012 - Demand Response and Light Control
ASHRAE Journal -November 2012 - B21
ASHRAE Journal -November 2012 - B22
ASHRAE Journal -November 2012 - B23
ASHRAE Journal -November 2012 - B24
ASHRAE Journal -November 2012 - 49
ASHRAE Journal -November 2012 - Building Sciences
ASHRAE Journal -November 2012 - 51
ASHRAE Journal -November 2012 - 52
ASHRAE Journal -November 2012 - 53
ASHRAE Journal -November 2012 - 54
ASHRAE Journal -November 2012 - 55
ASHRAE Journal -November 2012 - InfoCenter
ASHRAE Journal -November 2012 - 57
ASHRAE Journal -November 2012 - 58
ASHRAE Journal -November 2012 - 59
ASHRAE Journal -November 2012 - 60
ASHRAE Journal -November 2012 - 61
ASHRAE Journal -November 2012 - 62
ASHRAE Journal -November 2012 - 63
ASHRAE Journal -November 2012 - Data Centers
ASHRAE Journal -November 2012 - 65
ASHRAE Journal -November 2012 - 66
ASHRAE Journal -November 2012 - 67
ASHRAE Journal -November 2012 - Emerging Technologies
ASHRAE Journal -November 2012 - 69
ASHRAE Journal -November 2012 - 70
ASHRAE Journal -November 2012 - 71
ASHRAE Journal -November 2012 - Refrigeration Applications
ASHRAE Journal -November 2012 - 73
ASHRAE Journal -November 2012 - Engineer's Notebook
ASHRAE Journal -November 2012 - 75
ASHRAE Journal -November 2012 - Special Products
ASHRAE Journal -November 2012 - Washington Report
ASHRAE Journal -November 2012 - Products
ASHRAE Journal -November 2012 - Classified Advertising
ASHRAE Journal -November 2012 - Advertisers Index
ASHRAE Journal -November 2012 - Cover3
ASHRAE Journal -November 2012 - Cover4
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QJLWMC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_MCDEBX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WNYSQY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XATVOD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FJSHSS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_CCBZDS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XDEFVG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2023november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2023november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_VHGNBL
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WPKBNJ
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_UUVCDE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RTGDEW
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2023
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LKRFXS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_AZSOFG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ERCDBH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QWDFRV
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JHGVDF
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OPUYHG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SREIBM
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LRTGLK
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OKRFGH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2022november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2022november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TZSERA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LVRUIX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RPTVYZ
https://www.nxtbook.com/nxtbooks/ashrae/mini_pub_catalog
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XIYTGD
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2022
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RFGDOB
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PABXNU
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_REMKLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PICVBT
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_AOYTVW
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JQOPLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_IOYTBC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SGAJJF
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_IGHYER
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PDRKLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2021november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2021november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XCODFR
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QSLFGO
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ILKVNM
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2021
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OPDJKD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_VJKSRY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SDHUTC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JPPKRR
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SDLTTH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_CKLLES
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SLDOX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_HJETUK
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OLUHGE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2020october
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2020october_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ZERDGH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QVMNEO
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RTPOKE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_BBATRE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_STUBMW
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TPEMPE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JNMKDS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FBTTPA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WQMMNE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TVBRYN
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2020
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_KTUZMA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ABEDGD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201910
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201909
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019septmeber_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019september
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201908
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201907
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201906
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201905
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201904
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019april
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201903
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019march
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201902
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201901
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2019
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018december
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018october
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2018
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201810
https://www.nxtbook.com/nxtbooks/ashrae/ashraeinsights_201806
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201805
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201804
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201803
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201712
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201711
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201710
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201709
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201705
https://www.nxtbook.com/nxtbooks/ashrae/ashrae_meetinginsert_201610
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acrexindia
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer
https://www.nxtbook.com/nxtbooks/amca/2014summer2
https://www.nxtbook.com/nxtbooks/amca/2014summer
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acma_2014summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201311
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201309
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acmasupp_2013fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201305
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201303
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2013winter
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201211
https://www.nxtbook.com/nxtbooks/ashrae/achr_expo_mexico2012
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201209
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v3
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v2
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201205
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201203
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012winter
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201111_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201109_v2
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2011summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201105
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201103
https://www.nxtbookmedia.com