The built environment has a vast impact on the natural environment, human health and the economy. By adopting green building strategies, we maximise economic and environmental performance. Green construction methods can be integrated into buildings at any stage, from design and construction to renovation and deconstruction. However, the most significant benefits can be obtained if the design and construction teams take an integrated approach from the earliest stages of a building project. Potential benefits of green building include:
- Enhance and protect biodiversity and ecosystems
- Improve air and water quality
- Reduce waste streams
- Conserve and restore natural resources
- Reduce operating costs
- Create, expand and shape markets for green products and services
- Improve occupant productivity
- Optimise lifecycle economic performance
- Enhance occupant comfort and health
- Heighten aesthetic qualities
- Minimise strain on local infrastructures
- Improve overall quality of life
The green building rating systems have been in practice around the world for the past three decades. Developed and developing countries have their own rating systems and assessment/certification methods to qualify buildings as “green” or “sustainable.” Some of the prominent rating systems around the world that focus primarily on energy, environment and sustainability are: BREEAM (UK), CASBEE (Japan), Estidama Pearl Rating (UAE), GBAS (China), GeSBC (Germany), Green Globes (Canada), GREEN STAR (Australia), GRIHA (India), LEED (USA) and SAGRS (Saudi Arabia).
LEED, an internationally recognised green building certification system, developed by the U.S. Green Building Council (USGBC) in March 2000, became the base system for rating tools developed in many other countries. The LEED rating system provides building owners and operators with a framework for identifying and implementing practical and measurable green building design, construction, operations and maintenance solutions. It is applicable to new construction, existing buildings, commercial interiors, core and shell homes, neighbourhood developments, schools and retail buildings.
While LEED uses many different codes and standards for its procedural and equipment-level compliance requirements under different sections, for compliance on “Energy”, ASHRAE 90.1 remains the most recognised and specified standard to:
- Reduce energy use;
- Design for energy efficiency; and
- Promote renewable energy use
Revised every three years, the current version of ASHRAE 90.1 was issued in January 2023, with its primary focus being to improve energy efficiency in commercial buildings. The impact of the new version will be determined by a U.S. Department of Energy (DOE) study, which will quantify the expected energy savings.
The below table shows estimated energy use intensity by building type in the United States:
Table 1: Estimated Energy Use Intensity by Building Type – Standard 90.1-2019
New commercial buildings meeting the requirements of Standard 90.1-2019 that were analysed by DOE’s quantitative analysis exhibited national savings (compared to Standard 90.1-2016) of approximately:
- 4.7% in site energy;
- 4.3% in source energy;
- 4.3% in energy cost savings; and
- 4.2% in carbon emissions
HVAC equipment compliance requirements fall under the “Energy” section, and ASHRAE 90.1 is globally recognised as the method of compliance with other important factors apart from HVACR, including building envelope (insulation, glass, building material, etc.), water heating, power and lighting.
Section 6 of ASHRAE 90.1 specifies efficiencies, verification and labelling requirements specifically for HVAC equipment, including unitary air conditioners, condensing units, heat pumps, chillers, packaged terminal air conditioners and heat pumps, warm-air furnaces and combination warm-air furnaces/air-conditioning units, warm-air duct furnaces and unit heaters, gas- and oil-fired boilers, heat transfer equipment, variable refrigerant flow equipment, computer room units, commercial refrigerators and freezers, pool dehumidifiers and DX-DOAS units.
The section states that these equipment types shall have a minimum performance at the specified rating conditions, when tested in accordance with the specified Method of Test (MOT). Where multiple rating conditions or performance requirements are provided, the equipment shall satisfy all stated requirements, unless specifically exempted.
The equipment is to be tested based on its type and the availability of internationally recognised test standards and MOT – AHRI/ISO/CTI, etc. Technically, compliance with ASHRAE 90.1 or with green building codes requires AHRI certification, as the capacity and efficiency of the equipment on which the calculations are based must be verified.
In summary, since the HVAC equipment-level efficiencies are major contributors to the global movement toward energy efficiency and sustainability, the compliance requirements of the products and equipment must be carefully designed and monitored. Globally recognised standards and certification programmes are the key to that effort.
Dalip Singh is Senior Technical Analyst, AHRI MENA. He may be reached at DSingh@ahrinet.org.