scope:

INTRODUCTION

There continues to be a growing awareness about the impact of the built environment on the natural environment. The use of green engineering concepts has evolved quite rapidly in recent years and is now a legitimate and spreading movement in the HVAC&R and related engineering professions. Much of this recent work has been driven by the emergence of green architecture, also commonly referred to as sustainable or environmentally conscious architecture. This, in turn, is being encouraged by increased client demand for more sustainable buildings.

Interest in green buildings has been particularly evident in the concern about energy and water resource consumption, but also includes broader concerns such as material use, "smart" development and planning, etc. Many countries in the world now have green-building rating systems (voluntary) and/or codes (mandatory in some form or other). Organizations devoted specifically to this issue are now in existence in most countries. Not only have the messages contained in this outpouring of information attempted simply to explain what this issue is, they have promoted the concept of green design, exhorted to action, strived to motivate, warned of consequences from ignoring it, and instructed how to do it.

While this vast amount of promotion has been helpful, much has not been directly useful to the practicing designer for buildings (i.e., to the ASHRAE member involved on a day-to-day basis in the mechanical/electrical building system design process). ASHRAE identified a need for guidance on the greenbuilding concept specifically directed toward such practitioners. One key motivation for the development of this guide is that it contains information that has direct practical use. This guide is ASHRAE's way to provide information and guidance to the industry and practicing professionals.

Green is one of those words that can have many meanings, depending on the circumstances. One of these is the greenery of nature (e.g., grass, trees, and leaves). This symbolic reference to nature is the meaning this term relates to in this publication. The difference between a green and sustainable design is the degree to which the design helps to minimize the building impact on the environment while simultaneously providing a healthy, comfortable indoor environment. This guide is not intended to cover the full breadth of sustainability, but it is a good overview of many of the main topics. For key characteristics and more detailed discussion of sustainability, refer to the "Sustainability" chapter in the 2013 ASHRAE Handbook-Fundamentals (ASHRAE 2013).

The definition of green buildings inevitably extends beyond the normal daily concerns of HVAC&R designers alone, since the very concept places an emphasis on integrated design of mechanical, electrical, architectural, and other systems.

Specifically, the viewpoint held by many is that a green/sustainable building design is one that achieves high performance, over the full life cycle, in the following areas:

Minimizing natural resource consumption through more efficient utilization of nonrenewable energy and other natural resources, land, water, and construction materials, including utilization of renewable energy resources to strive to achieve net zero energy consumption.

Minimizing emissions that negatively impact our global atmosphere and ultimately the indoor environment, especially those related to indoor air quality (IAQ), greenhouse gases, global warming, particulates, or acid rain.

Minimizing discharge of solid waste and liquid effluents, including demolition and occupant waste, sewer, and stormwater, and the associated infrastructure required to accommodate removal.

Minimizing negative impacts on the building site.

Optimizing the quality of the indoor environment, including air quality, thermal regime, illumination, acoustics/noise, and visual aspects to provide comfortable human physiological and psychological perceptions.

Optimizing the integration of the new building project within the overall built and urban environment. A truly green/sustainable building should not be thought of or considered in a vacuum, but rather in how it integrates within the overall societal context.

Ultimately, even if a project does not have overtly stated green/sustainable goals, the overall approaches, processes, and concepts presented in this guide provide a design philosophy useful for any project. Using the principles of this guide, an owner or a member of his or her team can document the objectives and criteria to include in a project, forming the foundation for a collaborative integrated project delivery approach. This can lower design, construction, and operational costs, resulting in a lower total cost for the life of the project.