Standards, Guidelines, Codes
Guidelines (ASHRAE Definition) are used in designing, testing, evaluating specific products, concepts and practice. They are developed by consensus procedures that include public review and comments. Standards are developed from guidelines after extensive public review.
Standards (ASHRAE Definition) describe uniform methods for testing, design and practice. They are developed by consensus procedures that include public review and comments. Standards are not mandatory but they should be considered as minimum design requirement.
Standards and Guidelines are developed by professional societies, institutes and associations. These organizations are usually private (not the government). Application and conformance are therefore voluntary.
Codes are mandatory if they are issued by the government. It is the law of the country or the law within a jurisdiction within the country. They are set by City, State and Federal agencies and approved by Federal and State Congress or City Council. Since the government is not a professional or scientific organization, codes are based on national standards by professional societies. The local code can be more stringent or less stringent than the national standard.
There are also standards that are called codes that are issued by private professional organizations. The National Electrical Code (NEC) is issued by the National Fire Protection Association (NFPA). In 1994, the nation's model code organizations, (1) CABO: Council of American Building Officials, (2) BOCA: Building Officials and Code Administration, (3) ICBO: International Conference of Building Officials, and (4) SBCCI: Southern Building Codes Congress International, created the International Codes Council (ICC).
The purpose of the new coalition was to develop a single set of comprehensive codes for new residential and commercial buildings. The International Energy Conservation Code (IECC) was published by this group in 2000. IECC is based on the ASHRAE Standard 90.1/90.2/100. This group also jointly published the International Mechanical, Plumbing and other codes.
Examples of Standards that affect Building Energy Conservation
ASHRAE Standard 55-1992 : Thermal Environmental Conditions for Human Occupancy. (55 is the standard number and 1992 is the year it was last updated and issued).
ASHRAE Standard 62-2001 : Ventilation for Acceptable Indoor Air Quality.
ASHRAE Standard 90.1-2001 : Energy Standard for Buildings (Except Low-Rise Residential).
ASHRAE Standard 90.2-2001 ; Energy Efficient Design of Low-Rise Residential Buildings.
ASHRAE Standard 100-1995 : Energy Conservation in Existing Buildings.
ASHRAE Standard 129-1997 : Measuring Air Change Effectiveness (a LEED rating factor).
Background & History of Energy Standards & Codes
It took 50 years (1900-1950) for total annual US energy consumption to go from 4 million barrels of oil equivalent per day (MBOE) to 16 MBOE. By 1970 it was 32 MBOE and by the mid 1970s it was 40 MBOE. Energy use restrictions have slowed this growth to about 45 MBOE despite the increase demand for energy. Most of this was achieved through increased efficiency of use.
Until the early 1970s there were almost no restrictions on the amount of energy that buildings can use. Energy costs were low and energy supply was assumed to be boundless. The first cost of the building was the primary concern of designers and clients.
In 1973, due to political turmoil in the Middle East, the oil cartel nations quadrupled the price of oil. In the uncertainty and speculation that followed, prices at the gasoline pump went up from about $0.50 per gallon to almost $1.50 per gallon. A few years earlier it was about $0.35 per gallon. The average price of imported crude oil per barrel went up $3.00 in 1970 to $12.0 in 1973 to $37.00 in 1981. US oil import costs went from $3 billion in 1970 to $42 billion in 1978 to $80 billion in 1981. Utility costs also increased at the same rate and economic projections predicted fossil fuel escalation rates of up to 17 percent.
There was now pressure from the US government and all segments of society to conserve energy. Following energy conservation measures and due to less speculation and more confidence in the future the MBOE was 1996-98 is $12 to $22 and the cost of imported oil fell to about $50 billion.
Another factor contributing to the energy crisis in the US, are the restrictions on building new nuclear power plants following questions about its safety after the incident at 3-man-island. Nuclear power can be considered to be unlimited. In countries like France it is still the major source of power. The use of energy and the resulting air pollution has also raised concerns about (1) acid rain due to the sulfur content of fossil fuel, (2) global climate change due to carbon dioxide produced by the combustion of fossil fuel, and (3) ozone depletion in the upper atmosphere which affects solar radiation reaching the earth. Ozone depletion is due to CFC based refrigerants in air conditioning and refrigeration systems that use energy.
In 1974 ASHRAE introduced Standard 90 (STD90-74) for buildings. Later this standard was organized as STD90.1 for commercial buildings and STD90.2 for residential buildings. There is also a Standard 100 for existing commercial and residential buildings. The latest updates to these standards were established in 2001 (example STD90.1-01). ASHRAE Standard 90 gets more stringent in all categories with each update.
After 1974, several building energy analysis computer programs were developed so that designers and clients could evaluate buildings for energy consumption. They included TRACE from the Trane Company, AXCESS by the Electric Research Institute and E-CUBE by the Gas Research Association. In the late 1970s, the US Department of Energy (USDOE) released its first version of the DOE energy analysis program. The purpose was to set a standard for such analysis.
Standards are not mandatory. The first energy codes were issued by the States of California and Florida. Almost all energy codes today are based on ASHRAE Standard 90.
Federal buildings do not have to comply with any national or local code or standard. These buildings are covered by the Code of Federal Regulations (CFR). Like the non federal codes, CFRs also go through a process of development and approval similar to guidelines, standards and codes. CFRs are preceded by Executive Orders (EO) which is issued from the US President Office. An EO can require federal agencies like DOE and GSA to do something that is not covered by legislation. It can also exempt or make less stringent certain code requirements.
Executive Order 12759 - April 17, 1991:- Directed improved energy efficiency in 500,000 federal buildings (remodeling, etc).
- Established the Federal Energy Management Program (FEMP).
- 10% reduction of energy use in existing federal buildings by 1995 from 1985 base year.
- 20% reduction of energy use in existing federal buildings by 2000 from 1985 base year.
- Must use Life Cycle Costing in procurement (first cost purchases)
- 30% reduction of energy use in existing federal buildings by 2005 from 1985 base year.
- 20% reduction of energy use in existing federal industrial and laboratory facilities by 2005 from the 1990 base year.
- 35% reduction of energy use in existing federal buildings by 2010 from 1985 base year.
- 25% reduction of energy use in existing federal industrial and laboratory facilities by 2005 from the 1990 base year.
- Reduce greenhouse gas emissions related to energy use by 30% by the year 2010 compared to the emissions levels in 1990. (There is a direct formula relationship between the gases like CO2 and SO2 emitted and the energy used like electricity, fuel oil and natural gas).
- States must establish more stringent building energy codes
- States must consider Integrated Resource Planning for buildings (IRP: consider both supply energy use and peak demand use)
- States must establish minimum efficiency standards for commercial size mechanical and electrical equipment and lighting in buildings
- Private sector (ex. organizations representing various building products manufacturers) must establish minimum standards for windows, office equipment, luminaries, etc.
- Exempt Small Power Producers (SPPs) from the Public Utility Holding Company Act (PUHCA), This means that private buildings that generate their own power are exempt from the rules that apply to public utility companies (PUCs). PUCs must purchase and add to their grid the excess power from the SPPs at just and reasonable rates.
- Allow federal agencies to sign long term performance contracts up to 25 years. This is called Energy Service Contracts (ESCOs). The contractor recovers its costs through energy saved from existing building energy usage costs.
Federal facilities must install by January 1 2005, all energy and water conservation measures with payback periods less than 10 years. All federal building design and analysis must therefore include a life cycle cost analysis (LCCA).
Building Services Engineering and Energy Efficiency: The term
The term Heating, Ventilating & Air Conditioning (HVAC) is the science of providing clean, and comfortable Air conditions for humans in buildings and for maintaining the required air conditions for industrial processes in buildings. Refrigeration is used for cooling and various types of Fuels are used for heating. Water is the main medium used to distribute heating and cooling energy within buildings.
Building occupants also require water supply for drinking, washing and cleaning, and waste disposal systems that use water. Hospitals require the distribution of medical gases. This group of services fall under the term Plumbing. Building occupants, the building material contents and the building structure require Fire Protection. Water is still the best medium to put out fires. Other mediums are used where water can damage the contents of the space.
Buildings also require Lighting and tall buildings require Elevators. All of these services require Electrical Power for their operation. This group of services is also referred to as Mechanical, Electrical & Plumbing (MEP) in the USA and as Building Services Engineering (BSE) in the United Kingdom and some other parts of the world.
The MEP or BSE services described above consume Energy directly. MEP services consist of Air, Water & Electrical Distribution Systems connecting various types of Equipment.
Energy Codes & Standards:
US Energy Codes are based on ASHRAE (American Society of Heating, Refrigeration & Airconditioning Engineers) Standard 90 (STD90). STD90 was first issued in 1974 and the latest version is 2001. The lighting component of STD90 is jointly developed and issued by ASHRAE and IESNA (Illumination Engineering Society of North America). A local code can be more stringent than certain components of STD90 and less stringent for other components.
Energy Codes apply to: (1) New buildings, (2) Additions to new buildings, and (3) New construction in existing buildings. Energy Codes do not apply to (1) Small Single family & mobile homes, and (2) Industrial facilities.
Energy Code requirements apply to two classes of buildings
Residential buildings- Low-rise, multi-family not exceeding 4 stories where occupants are primarily permanent (no motels)
- It includes townhouses, row-houses, apartments, rooming houses, dormitories, fraternities, sororities, convents, rectories, monasteries, nursing homes, etc.
- High-rise residential buildings (apartment, condos, hotels)
- Office buildings
- Educational (schools, colleges, university campuses)
- Convention centers, Performing arts centers
- Miscellaneous (Indoor stadiums, Hospitals, etc.)
ASHRAE Standard 90 does not apply to the processes in industrial buildings. Industrial processes vary considerably and it is in the interest of the industrial facility to utilize energy efficient procedures since the savings in costs are significant.
The term high-rise and tall buildings have different definitions throughout the world. In Singapore, for example, the building is high-rise if the local fire truck cannot fight the fire from the outside. In other locations it can be say 80 feet or 10 stories. The ASHRAE Technical Committee for Tall Buildings TC9.12 defines a tall building as one that exceeds 300 feet (91 m).
The building must show compliance in four categories:
- Envelope (walls, roofs, windows, skylights and doors)
- Illumination (lighting) and electrical power distribution
- HVAC
- Domestic Hot Water (DHW) heaters and other (escalators, elevators)
There are two methods of STD90 and Code compliance
- Prescriptive
- Energy Cost Budget (ECB) or non-prescriptive or total performance compliance
The prescriptive method establishes minimum performance criteria for each of several parameters, (U-values, COPs, etc.,) for each of the four categories of envelope, lighting, HVAC and DHW for the location. STD90 and the International Energy Code (IECC) provides prescriptive criteria for several locations around the world.
The ECB method allows performance parameters to exceed the minimum prescriptive limits for some components within the four categories, but this has to be balanced with more stringent parameters for other components.
The ECB method requires the use of a certified energy analysis simulation software program. The analysis and simulation must be for each hour of the year (8760-hours) and it must use 8760-hour weather data for the location. The simulation must include a utility rate analysis using current utility rates that apply to the building under design. The purpose of this is to include the impact of electrical demand (affects source energy) in the analysis.
The ECB method requires that the building (the full architectural model) be first analyzed with the prescriptive parameters (this building is called the Standard or Prototype Building) and then with proposed parameters (the Proposed Building). The energy cost of the proposed building must not exceed that of the standard building. The proposed building can also be compared to some other standard building of the same type that is acceptable to the code authorities.
There are mandatory requirements with both the prescriptive and performance methods.
With the prescriptive method the proposed building design criteria must be equal to or be better than every item of the prescriptive criteria in each of the categories of envelope, lighting and mechanical systems. If even one component such as glazing or wall does not meet its individual requirement, the entire envelope does not comply. It is possible to show prescriptive compliance without the use of a computer simulation program. The ComCheck-EZ computer program has the prescriptive criteria database built into the program, for different locations in the US, that it uses to check proposed design.
The performance approach allows separate overall envelope or lighting or mechanical systems compliance or total building compliance using all categories. Weaknesses in one component or category can be compensated within other components and categories. In the case of separate overall envelope compliance for example, if the wall glazing area exceeds 50% (the ASHRAE STD90 limit) then this can be offset by using more stringent criterion for other items such as envelope material U-factors and glass shading coefficients.
Performance compliance requires the use of building energy simulation programs to compare the annual energy consumption and utility costs by using the prescriptive and proposed criterion applied to the same building geometric model and configuration. Building energy analysis must use 8760 hour (every hour of the year) weather data.
COMPUTER PROGRAMS FOR BUILDING ENERGY ANALYSIS
Programs developed with grants from the US Department of Energy (USDOE)
| 1. DOE2.1E | USDOE, Lawrence Berkeley National Lab (LBNL) |
| 2. ENERGYPLUS | USDOE, University of Illinois-Champaign (UIUC), LBNL, GARD Analytics |
| 3. BLAST | UIUC, US Army Corps of Engineers (USACE), Champaign |
Programs based on DOE2.1E (to check for Code Compliance)
| 4. COMCHECK | USDOE, Pacific Northwest Lab (PNL). |
| 5. COMCHECKEZ | USDOE, PNL. Checks for prescriptive compliance |
| 6. PERFORM 2001 | California Energy Commission (CEC). Title 24 compliance |
| 7. ENERGYPRO 3.0 | CEC Title 24. Includes database of envelope & equipment performance |
Enhanced versions of DOE2.1E (with forms & graphics user interface)
| 8a. ADM-DOE-2 | 8b. Compare-IT | 8c. DOE-PLUS | 8d. EZ-DOE |
| 8e. FTI-DOE2 | 8f. PRC-DOE-2 | 8g. Visual-DOE | 8h. Compare-IT |
Programs based on DOE2.2 (advanced version of DOE2.1E not supported by USDOE)
| 9. PowerDOE | Electrical Power Research Institute (EPRI) |
| 10. EQUEST | James J. Hirsch (JJH) and California Utility Companies |
| 11. DOE2.2 | USDOE, LBNL, EPRI, JJH |
Independent Energy Programs (based on actual equipment performance test data)
| 12. TRACE-700 | Trane Company |
| 13. SYSTEM-Analyzer | Trane Company |
| 14. HAP 5.0 | Carrier Corporation |
DOE2.1E, TRACE, HAP Programs
Measuring Units:
Two systems of units are used for measurement in the USA. The Inch-Pound (I-P) also known as English units and the System-International (S-I) also known as Metric units. The rest of the world use the S-I system only. Within each system there are several more types of units for a particular type of measurement. The several different measurement methods and scales were subjectively created by people over a period of time and in different parts of the world. The three basic measurement units are Length, Weight and Time
Length:
I-P unit = Foot, 12 inches = foot, 3 feet = yard, 5,280 feet = mile, 1,760 yards = mile. S-I unit = Meter, 1 meter = 100 centimeters = 1,000 millimeters, 1 kilometer = 1,000 meters.
Weight:
I-P unit = Pound (lb), 16 ounces = lb, 2,000 lbs = 1 ton (short), 2,240 lbs = 1 ton (long). S-I unit = Gram, 1,000 grams = Kilogram (kg), 1,000 milligrams = gram.
Area:
I-P unit = Square-Feet (ft2), 1 ft2 = 144 in2, 1 acre = 43,560 ft2, = 4.840 sq.yds. S-I unit = Square-Meter (m2), 1 square kilometer = 1,000,000 m2
Volume:
I-P unit = Cubic-Feet (ft3), 1 ft3 = 7.481 gallons water = 62.4 lbs water = 29.92 quarts. S-I unit = Cubic-Meter (m3), 1 m3 = 1,000 liters = 1,000 kg water.
Time and Angle (I-P & S-I):
Unit = Hour, 60 minutes = hour, 60 seconds = minute, 1 day = 24 hours, 1 year = 8,760 hours. Circle = 360 degrees = 2*PI radians, PI = 3.141593, 1 Radian = 57.296 degrees.
I-P to S-I Conversion Factors
