Degelman, L.

Texas A&amp;M Repository

Simulated Impacts of Global Warming on Building Thermal Loads Throughout the 21st CenturyPresented at ASHRAE Seminar 48“Climate Change: Modeling the Weather and Its Potential Impacts on Building Performance”Tuesday, 8:00 a.m., 26 June 2007Long Beach, CAby Larry O. Degelman, P.E.Professor Emeritus of ArchitectureTexas A&M Universityldegelman@suddenlink.netOutlineTrends in global warmingModels matched against global warming recordsFactors contributing to global warmingSelection of a temperature prediction model for a case studySelection of a case study building and 6 citiesTemperature plots for years 2007 and 2100 Impacts on building air-conditioning loadsCO-2 increases from added building a.c. loads Building contribution to greenhouse gases Nomenclature DCV – Demand Control Ventilation ECM – Energy Conservation Measures ERV – Energy Recovery Ventilator EUI – Energy Utilization Index (Annual energy use per unit floor area) HadCM3 – Hadley Climate Model (European) IPCC – Intergovernmental Panel on Climate Change GFDL - Geophysical Fluid Dynamics Laboratory (NOAA) GISS – Goddard Institute for Space Studies (NASA) NCDC – National Climate Data Center NOAA – National Oceanic & Atmospheric Association.Global warming web sitesNOAA (National Oceanic and Atmospheric Administration): http://lwf.ncdc.noaa.gov/oa/climate/globalwarming.htmlNOAA’s Geophysical Fluid Dynamics Laboratory: http://www.gfdl.gov/~tk/climate_dynamics/climate_impact_webpage.html1880-2001 Trends (source: NOAA) 1895-2006 Historic trends (source: NOAA)ESL-TR-07-06-01Projections for the UK by the HadCM3 modelHistoric records compared to predictions by 14 models (source: IPCC)Trendsshown byNCDCrecordsPredicted changes likelyA report issued by an IPCC working group 1, “Climate Change 2001: The Scientific Basis”, lists “very likely” global climate changes for the 21st century.  Among those are: Higher daily maximum temperatures and more hot days over nearly all of the Earth’s land, Warmer overnight low temperatures, (minimum daily temperatures) Fewer cold days and frost days over nearly all the land, and Reduced differences between daily highs and lows over nearly all land areas (smaller diurnal ranges.)Predicted temperatures Using the projection of doubling of atmospheric carbon dioxide over the next 70 years, experiments with NOAA’s GFDL climate model reveal that the surface air temperature warming would be particularly large over the mid- and high-latitude continental regions, and lower for the low-latitude regions.  Data in their report show increases of about 9F (5C) for areas in northern Europe and northern U.S., 6F (3.3C) for southern U.S. latitudes and southern Australia, and about 2.0F (1.1C) for equatorial land areas. NOAA’s GFDL model predictionsESL-TR-07-06-01CASE-STUDY BUILDINGEngineering office/ classroom building that meets ASHRAE Std 90.1-2004Simulation steps:1. Simulate building as-is using today’s climate data from ASHRAE 2005 HOF.2. Simulate building using projected climate data for year 2100 from the GFDL model.3. Simulate same as step 2 but adding occupancy sensors for lighting control and demand control ventilation and incorporating ERVs in place of standard exhaust fans.Case study 10-story office building was simulated in 6 cities Latitude effects on average temperature increases predicted by the GFDL modelHigher latitude cities (London, Minneapolis), +9F by year 2100.Mid-latitude cities (Houston, Sydney), +6F by year 2100.Lower latitude cities (Bangkok,Caracas), +2F by year 2100.Relationships between high, low, and average temperature and diurnal range H – L = MDR (mean diurnal range) …….... (eq. 1) H + L = 2 * Tave ………………………...… (eq. 2) Or ∆H – ∆L = ∆MDR (mean diurnal range) . .(eq. 1A) ∆H + ∆L = 2 * ∆Tave ………………....… (eq. 2A)Min-Max temperatures as a function of reduced diurnal swing (for ∆Tave = 6.7F)Change in diurnalswing (∆MDR)Increase in daily max. temp.(∆ H) Increase in daily min. temp.(∆ L) -1.8 F 5.8 F 7.6 F-3.6 F 4.9 F 8.5 F-5.4 F 4.0 F 9.4 FESL-TR-07-06-01CityNameLat.classLat.(deg.)ASHRAE Design Temp. (F)MDR(F) * GFDL temp chg (F)MDR chg(F) *Year 2100 design temp. (˚F)sum. #wint#summer winterchg val. chg val.London High 51.2N 77.2 26.4 17.6 9 -3.6 7 84.2 11 37.4Minn. High 44.9N 87.8 -9.4 19.1 9 -3.6 7 94.8 11 1.6Houston Mid 30N 94.9 31.5 18.2 6 -2.7 4.7 99.4 7.3 38.8Sydney Mid 33.9S 83.4 46.3 12.1 6 -2.7 4.7 88.1 7.3 53.6Bangkok Low 13.7N 95 68.5 16.7 2 -1.8 1.1 96.1 2.9 71.4Caracas Low 10.6N 90.9 69.9 12.6 2 -1.8 1.1 92 2.9 72.8* MDR = Mean Daily Range (F)# sum.=summer 1% desgn val.; wint.=winter 99% val (2005 ASHRAE HOF)Existing and future design temperatures for 6 case study cities Energy simulation tool w/ built-in weather data generator for annual predictionData for MinneapolisYear 2007Year 2100DB & DP (January 5)Htg Loads (January 5)DB & DP (July 8)Clg Loads (July 8)[In Minneapolis]Peak Cooling & Heating LoadsESL-TR-07-06-01Results for all 6 citiesPeak Heating LoadAnnual Heating EnergyPeak Cooling LoadAnnual Cooling EnergyWhole Building Peak DemandESL-TR-07-06-01Whole-building Energy Utilization IndexHow buildings impact the global environmentGreenhouse Gas Emissions Conclusions1. Cooling loads have far greater variations due to latitude than from expected global warming over the next century.2. Global warming does cause increased cooling loads, the highest percentages being at high and middle latitudes.3. Significant cooling savings at low latitudes when using motion sensors and air-to-air heat exchangers.  This easily counteracts the added loads from global warming.(cont.)Conclusions (cont.)4. Global warming decreases heating loads, but further decreases are possible from occupancy sensors and heat exchangers.5. Only modest changes in EUI from global warming – due to offsetting effects of increased cooling and decreased heating.6. Energy increases due to global warming are easily offset by use of known energy conservation measures (ECMs) like occupancy sensors for lighting control and demand ventilation.Thank you!ESL-TR-07-06-01

Simulated Impacts of Global Warming on Building Thermal Loads Throughout the 21st Century

Texas A&M University

Simulated Impacts of Global 
Warming on Building Thermal 
Loads Throughout the 21st Century
Presented at ASHRAE Seminar 48
“Climate Change: Modeling the Weather and Its 
Potential Impacts on Building Performance”
Tuesday, 8:00 a.m., 26 June 2007
Long Beach, CA
by 
Larry O. Degelman, P.E.
Professor Emeritus of Architecture
Texas A&M University
ldegelman@suddenlink.net
Outline
Trends in global warming
Models matched against global warming records
Factors contributing to global warming
Selection of a temperature prediction model for 
a case study
Selection of a case study building and 6 cities
Temperature plots for years 2007 and 2100
 Impacts on building air-conditioning loads
CO-2 increases from added building a.c. loads 
Building contribution to greenhouse gases 
Nomenclature
 DCV – Demand Control Ventilation
 ECM – Energy Conservation Measures
 ERV – Energy Recovery Ventilator
 EUI – Energy Utilization Index (Annual energy use per 
unit floor area)
 HadCM3 – Hadley Climate Model (European)
 IPCC – Intergovernmental Panel on Climate Change
 GFDL - Geophysical Fluid Dynamics Laboratory (NOAA)
 GISS – Goddard Institute for Space Studies (NASA)
 NCDC – National Climate Data Center
 NOAA – National Oceanic & Atmospheric Association.
Global warming web sites
NOAA (National Oceanic and Atmospheric 
Administration):
 http://lwf.ncdc.noaa.gov/oa/climate/global
warming.html
NOAA’s Geophysical Fluid Dynamics 
Laboratory:
 http://www.gfdl.gov/~tk/climate_dynamics
/climate_impact_webpage.html
1880-2001 Trends (source: NOAA) 1895-2006 Historic trends (source: NOAA)
ESL-TR-07-06-01
Projections for the UK by the 
HadCM3 model
Historic records compared to predictions 
by 14 models (source: IPCC)
Trends
shown by
NCDC
records
Predicted changes likely
A report issued by an IPCC working group 1, 
“Climate Change 2001: The Scientific Basis”, lists 
“very likely” global climate changes for the 21st 
century.  Among those are:
 Higher daily maximum temperatures and more hot days 
over nearly all of the Earth’s land,
 Warmer overnight low temperatures, (minimum daily 
temperatures)
 Fewer cold days and frost days over nearly all the land, 
and
 Reduced differences between daily highs and lows over 
nearly all land areas (smaller diurnal ranges.)
Predicted temperatures
 Using the projection of doubling of atmospheric 
carbon dioxide over the next 70 years, 
experiments with NOAA’s GFDL climate model 
reveal that the surface air temperature warming 
would be particularly large over the mid- and 
high-latitude continental regions, and lower for the 
low-latitude regions.  Data in their report show 
increases of about 9F (5C) for areas in northern 
Europe and northern U.S., 6F (3.3C) for southern 
U.S. latitudes and southern Australia, and about 
2.0F (1.1C) for equatorial land areas. 
NOAA’s GFDL model predictions
ESL-TR-07-06-01
CASE-STUDY BUILDING
Engineering office/ 
classroom building that 
meets ASHRAE Std 
90.1-2004
Simulation steps:
1. Simulate building as-is using today’s 
climate data from ASHRAE 2005 HOF.
2. Simulate building using projected climate 
data for year 2100 from the GFDL model.
3. Simulate same as step 2 but adding 
occupancy sensors for lighting control and 
demand control ventilation and 
incorporating ERVs in place of standard 
exhaust fans.
Case study 10-story office building 
was simulated in 6 cities Latitude effects on average temperature increases predicted by the GFDL model
Higher latitude cities (London, 
Minneapolis), +9F by year 2100.
Mid-latitude cities (Houston, Sydney), 
+6F by year 2100.
Lower latitude cities (Bangkok,Caracas), 
+2F by year 2100.
Relationships between high, low, and 
average temperature and diurnal range
 H – L = MDR (mean diurnal range) …….... (eq. 1)
 H + L = 2 * Tave ………………………...… (eq. 2)
 Or
 ∆H – ∆L = ∆MDR (mean diurnal range) . .(eq. 1A)
 ∆H + ∆L = 2 * ∆Tave ………………....… (eq. 2A)
Min-Max temperatures as a function of 
reduced diurnal swing (for ∆Tave = 6.7F)
Change in diurnal
swing 
(∆MDR)
Increase in daily 
max. temp.
(∆ H) 
Increase in daily 
min. temp.
(∆ L) 
-1.8 F 5.8 F 7.6 F
-3.6 F 4.9 F 8.5 F
-5.4 F 4.0 F 9.4 F
ESL-TR-07-06-01
City
Name
Lat.
class
Lat.
(deg.)
ASHRAE 
Design 
Temp. (F)
MDR(F) * GFDL temp 
chg (F)
MDR 
chg(F) *
Year 2100 
design temp. (˚F)
sum. 
#
wint
#
summer winter
chg val. chg val.
London High 51.2N 77.2 26.4 17.6 9 -3.6 7 84.2 11 37.4
Minn. High 44.9N 87.8 -9.4 19.1 9 -3.6 7 94.8 11 1.6
Houston Mid 30N 94.9 31.5 18.2 6 -2.7 4.7 99.4 7.3 38.8
Sydney Mid 33.9S 83.4 46.3 12.1 6 -2.7 4.7 88.1 7.3 53.6
Bangkok Low 13.7N 95 68.5 16.7 2 -1.8 1.1 96.1 2.9 71.4
Caracas Low 10.6N 90.9 69.9 12.6 2 -1.8 1.1 92 2.9 72.8
* MDR = Mean Daily Range (F)
# sum.=summer 1% desgn val.; wint.=winter 99% val (2005 ASHRAE HOF)
Existing and future design temperatures 
for 6 case study cities Energy simulation tool w/ built-in weather 
data generator for annual prediction
Data for Minneapolis
Year 
2007
Year 
2100
DB & DP (January 5)
Htg Loads (January 5)
DB & DP (July 8)
Clg Loads (July 8)[In Minneapolis]
Peak Cooling & Heating Loads
ESL-TR-07-06-01
Results for all 6 cities
Peak Heating Load
Annual 
Heating 
Energy
Peak Cooling Load
Annual 
Cooling 
Energy
Whole Building Peak Demand
ESL-TR-07-06-01
Whole-building 
Energy 
Utilization 
Index
How buildings impact the global environment
Greenhouse Gas Emissions Conclusions
1. Cooling loads have far greater variations due to latitude 
than from expected global warming over the next century.
2. Global warming does cause increased cooling loads, the 
highest percentages being at high and middle latitudes.
3. Significant cooling savings at low latitudes when using 
motion sensors and air-to-air heat exchangers.  This easily 
counteracts the added loads from global warming.
(cont.)
Conclusions (cont.)
4. Global warming decreases heating loads, 
but further decreases are possible from 
occupancy sensors and heat exchangers.
5. Only modest changes in EUI from global 
warming – due to offsetting effects of 
increased cooling and decreased heating.
6. Energy increases due to global warming are 
easily offset by use of known energy 
conservation measures (ECMs) like 
occupancy sensors for lighting control 
and demand ventilation.
Thank you!
ESL-TR-07-06-01


English

https://oaktrust.library.tamu.edu/bitstream/1969.1/93354/1/ESL-TR-07-06-01.pdf

Simulated Impacts of Global Warming on Building Thermal Loads Throughout the 21st Century

Abstract

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Texas A&M Repository

Texas A&M University

Simulated Impacts of Global Warming on Building Thermal Loads Throughout the 21st Century

Abstract

Similar works

Full text

Available Versions

Texas A&amp;M Repository

Texas A&M University

Texas A&M Repository