ASHRAE Journal - September 2009 - 27

Case Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case Description Façade and Gains,* No Shading Devices Façade and Gains,* 1 m Overhangs and Side Fins Façade and Gains,* 1.5 m Overhangs and Side Fins Gains,* Improved Glazing, No Shading Devices Gains,* Improved Glazing, 1 m Overhangs and Side Fins Gains,* Improved Glazing, 1.5 m Overhangs and Side Fins Internal Gains* Reduced by 25%, Improved Glazing, 1.5 m Overhangs and Side Fins Internal Gains* Reduced by 50%, Improved Glazing, 1.5 m Overhangs and Side Fins Occupants Equipment (kWh/m2 · yr) (kWh/m2 · yr) Lighting (kWh/m2 · yr) Windows (kWh/m2 · yr) Walls (kWh/m2 · yr) Total (kWh/m2 · yr) 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 23.4 23.4 23.4 23.4 23.4 23.4 17.5 11.7 32.2 32.2 32.2 32.2 32.2 32.2 24.1 16.1 31.9 17.8 15.1 23.0 13.3 11.4 3.9 3.9 2.4 3.0 3.0 2.8 3.2 3.2 3.2 3.2 96.5 83.0 80.4 88.0 78.8 76.9 55.5 41.6 *Standard 90.1-2004 recommendations. Table 1: Annual gains (sensible only) by end-use energy consumption. Envelope energy demands include sensible conduction 350 and solar loads, along with latent and sensible infiltration load contributions. Occupant energy demands 300 include the sensible and latent loads associated with the occupants, as well as the outside air requirements. 250 For this work, lighting and equipment loads are presumed to be sensible loads only, although it is realistic 200 to expect latent components from office and kitchen equipment, for example. Finally, building system 150 efficiencies include installed mechanical component efficiencies, configuration and control strategies. 100 A net zero building always relies on a renewable energy contribution. This article focuses on 50 technologies that can be closely integrated with the building design and fit within the building footprint. 0 The contribution of solar energy harvested through Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 photovoltaic cells and concentrating solar collectors Sensible Cooling (Gains) Domestic Hot Water Latent Cooling (Occupant) are included in the parametric study. This strategy Sensible Cooling (Air) Light/Equipment acknowledges that Abu Dhabi does not have viable, Latent Cooling (Air) Fans/Pumps/Miscellaneous sustained wind energy potential. Net zero energy demand, as discussed here, is Figure 1: Total building cooling and thermal loads by end use (kWh/m2 · yr). based on a net zero annual energy requirement with no penalties for storage or temporary borrowing of energy ft (46 m) wall length, and 13 ft (4 m) floor-to-ceiling height. from a district system. Additionally, it is assumed that the A window-to-wall ratio of 30% was evenly distributed among quality of the energy produced is equivalent to the need for all four exposures. The building envelope was initially modthis building: this implies equivalent value of low-grade hot eled to represent ASHRAE Standard 90.1-2004 minimum water and electricity. These assumptions are baseline and requirements for a hot climate (ASHRAE Climate Type 4B). permit an easier comparison of use and production. As a Initial estimates for internal gains were established using screening process, these assumptions are a reasonable start the Standard 90.1-2004 recommended energy densities and to show how much solar energy lands on a site versus that schedules for occupancy, lighting, and equipment/plug load amount required to operate the building. However, the type gains. The modeled office building was simulated for a typiof on-site energy production and its conversion efficiency is cal year in a representative hot climate using the Abu Dhabi critical to the success of achieving a net zero energy building. IWEC weather data.3 The base model was simulated for eight scenarios representBuilding Energy Consumption ing the base case described previously, as well as cases with The first step in a screening level calculation is estimating improved shading and glazing systems (Table 1). The results the building’s energy demand. For this purpose a whole- from these simulations are shown in Table 1 and Figure 1. building energy model was created to predict building loads. For a large footprint office space, the gains to a space are Using a public and freely available software product, a simu- dominated by windows (solar transmitted and thermally lation model of a typical office tower floor was created. A conducted), lighting, and equipment loads. When good solar simple floor plan was modeled with a square footprint, 151 shading practices are used, the window gains can be reduced September 2009 ASHRAE Journal 27

ASHRAE Journal - September 2009

Table of Contents for the Digital Edition of ASHRAE Journal - September 2009

ASHRAE Journal - September 2009
Contents
Commentary
Industry News
Letters
Meetings and Shows
Getting to Net Zero
Feature Articles
How High Can You Go? Building Height and Net Zero
Lab for Learning
Solar Hot-Water Heating System: Lessons Learned
50th Anniversary—Low Pressure Steam Heating Systems
Building Sciences
Products
Emerging Technologies
People
Classified Advertising
Advertisers Index
ASHRAE Journal - September 2009 - ASHRAE Journal - September 2009
ASHRAE Journal - September 2009 - Cover2
ASHRAE Journal - September 2009 - 1
ASHRAE Journal - September 2009 - 2
ASHRAE Journal - September 2009 - Contents
ASHRAE Journal - September 2009 - 4
ASHRAE Journal - September 2009 - Commentary
ASHRAE Journal - September 2009 - Industry News
ASHRAE Journal - September 2009 - 7
ASHRAE Journal - September 2009 - 8
ASHRAE Journal - September 2009 - 9
ASHRAE Journal - September 2009 - Letters
ASHRAE Journal - September 2009 - 11
ASHRAE Journal - September 2009 - 12
ASHRAE Journal - September 2009 - 13
ASHRAE Journal - September 2009 - 14
ASHRAE Journal - September 2009 - 15
ASHRAE Journal - September 2009 - Meetings and Shows
ASHRAE Journal - September 2009 - 17
ASHRAE Journal - September 2009 - Feature Articles
ASHRAE Journal - September 2009 - 19
ASHRAE Journal - September 2009 - 20
ASHRAE Journal - September 2009 - 21
ASHRAE Journal - September 2009 - 22
ASHRAE Journal - September 2009 - 23
ASHRAE Journal - September 2009 - 24
ASHRAE Journal - September 2009 - 25
ASHRAE Journal - September 2009 - How High Can You Go? Building Height and Net Zero
ASHRAE Journal - September 2009 - 27
ASHRAE Journal - September 2009 - 28
ASHRAE Journal - September 2009 - 29
ASHRAE Journal - September 2009 - 30
ASHRAE Journal - September 2009 - 31
ASHRAE Journal - September 2009 - 32
ASHRAE Journal - September 2009 - 32a
ASHRAE Journal - September 2009 - 32b
ASHRAE Journal - September 2009 - 33
ASHRAE Journal - September 2009 - 34
ASHRAE Journal - September 2009 - 35
ASHRAE Journal - September 2009 - 36
ASHRAE Journal - September 2009 - 37
ASHRAE Journal - September 2009 - Lab for Learning
ASHRAE Journal - September 2009 - 39
ASHRAE Journal - September 2009 - 40
ASHRAE Journal - September 2009 - 41
ASHRAE Journal - September 2009 - 42
ASHRAE Journal - September 2009 - 43
ASHRAE Journal - September 2009 - Solar Hot-Water Heating System: Lessons Learned
ASHRAE Journal - September 2009 - 45
ASHRAE Journal - September 2009 - 46
ASHRAE Journal - September 2009 - 47
ASHRAE Journal - September 2009 - 48
ASHRAE Journal - September 2009 - 49
ASHRAE Journal - September 2009 - 50
ASHRAE Journal - September 2009 - 51
ASHRAE Journal - September 2009 - 52
ASHRAE Journal - September 2009 - 53
ASHRAE Journal - September 2009 - 50th Anniversary—Low Pressure Steam Heating Systems
ASHRAE Journal - September 2009 - 55
ASHRAE Journal - September 2009 - 56
ASHRAE Journal - September 2009 - 57
ASHRAE Journal - September 2009 - 58
ASHRAE Journal - September 2009 - 59
ASHRAE Journal - September 2009 - 60
ASHRAE Journal - September 2009 - 61
ASHRAE Journal - September 2009 - 62
ASHRAE Journal - September 2009 - 63
ASHRAE Journal - September 2009 - 64
ASHRAE Journal - September 2009 - 65
ASHRAE Journal - September 2009 - 66
ASHRAE Journal - September 2009 - 67
ASHRAE Journal - September 2009 - 68
ASHRAE Journal - September 2009 - 69
ASHRAE Journal - September 2009 - 70
ASHRAE Journal - September 2009 - 71
ASHRAE Journal - September 2009 - Building Sciences
ASHRAE Journal - September 2009 - 73
ASHRAE Journal - September 2009 - 74
ASHRAE Journal - September 2009 - 75
ASHRAE Journal - September 2009 - 76
ASHRAE Journal - September 2009 - 77
ASHRAE Journal - September 2009 - 78
ASHRAE Journal - September 2009 - 79
ASHRAE Journal - September 2009 - 80
ASHRAE Journal - September 2009 - 81
ASHRAE Journal - September 2009 - Products
ASHRAE Journal - September 2009 - 83
ASHRAE Journal - September 2009 - Emerging Technologies
ASHRAE Journal - September 2009 - 85
ASHRAE Journal - September 2009 - 86
ASHRAE Journal - September 2009 - 87
ASHRAE Journal - September 2009 - 88
ASHRAE Journal - September 2009 - 89
ASHRAE Journal - September 2009 - People
ASHRAE Journal - September 2009 - 91
ASHRAE Journal - September 2009 - 92
ASHRAE Journal - September 2009 - Classified Advertising
ASHRAE Journal - September 2009 - 94
ASHRAE Journal - September 2009 - 95
ASHRAE Journal - September 2009 - Advertisers Index
ASHRAE Journal - September 2009 - Cover3
ASHRAE Journal - September 2009 - 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