Energy Savings Potential and RD&D Opportunities for Commercial Building HVAC Systems

Abstract

The U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Program (BT) commissioned this assessment of heating, ventilation, and airconditioning (HVAC) technologies for U.S. commercial buildings. The main objectives of this study were to:  Identify a wide range of technology options in varying stages of development that could reduce commercial HVAC energy consumption;  Provide in-depth analysis of priority technology options, including: technical energysavings potential 1 ; applicability to different building or HVAC equipment types; nonenergy benefits; and perceived barriers to market adoption.  Develop suggestions for potential research, development and demonstration (RD&D) initiatives that would support further development of the technology options that are most promising based on technical energy-savings potential, potential fit with DOE BT's RD&D portfolio, cost and complexity, and other factors. viii U.S. Department of Energy Figure ES-1: Selection and Screening Process We first generated a comprehensive list of 182 technology options (listed in Appendix A) from a variety sources including: manufacturers' websites, industry publications, government organizations, university research, and internal Navigant experts. Through this initial survey, we cataloged general information about each technology such as its potential energy-efficiency impact and potential applicability to various commercial HVAC systems. After examining the initial list, we removed 125 technology options , leaving 57 technology options that demonstrated the highest potential to reduce HVAC energy consumption in commercial buildings, but that have not yet been adopted widely by the market (see Table ES-1). Step 1-Develop initial list of technology options Step 2-Develop the initial screening criteria Step 3-Identify 50 to 70 technology options for preliminary study Step 4-Analyze energy savings potential, economics and barriers for adoption of the selected technology options Step 5-Develop scoring criteria to evaluate the selected technology options Step 6-Select 15 to 20 technology options for more in-depth study ix U.S. Department of Energy Table ES-1: 57 Technology Options Selected for Further Study Components (24) Equipment (13)

Giant elastocaloric effect covering wide temperature range in columnar-grained Cu71.5Al17.5Mn11 shape memory alloy

“…[1][2][3][4][5] Among all alternative non-vapor-compression technologies for refrigeration, elastocaloric refrigeration has been evaluated to be one of the most potential ways owing to its higher coefficient of performance and lower device cost. 6 Here, elastocaloric effect refers to the temperature change under adiabatic conditions of a given material during uniaxial loading or unloading, which is directly related to the isothermal entropy change of the reversible solid-to-solid phase transformation. Shape memory alloys (SMAs) undergo a reversible first-order diffusionless structure transition, making it capable of recovering inelastic deformation upon unloading.…”

“…Compared with the magnetocaloric materials, SMAs for elastocaloric refrigeration show a larger reversible entropy change and an adiabatic temperature change, e.g., a temperature decrease of 17 K was observed for Ni-Ti wire during fast unloading, 7 as well as 6-7 K for Cu-Zn-Al polycrystalline sample. 8 Besides, the reversible martensitic transformation in SMAs is induced by uniaxial stress, which is easily controllable and relatively low in some alloys, for example, an applying stress of less than 100 MPa is simply required in Fe-Pd 9 and Ni-Mn-In-Co. 10 Moreover, high cyclic stability can be realized by tuning chemical composition and tailoring microstructure in SMAs; a Ni-Ti-Cu film was found to be capable of undergoing up to 10 6 The refrigeration capability (RC) of a given elastocaloric material, which is frequently used as a key value for the evaluation of a refrigeration system, is defined as 2…”

Review of Residential Comfort Control Products and Opportunities

“…This table shows how most of the products on the market today that could help detect and communicate faults from the refrigerant side of heat pump and air-conditioning systems are not permanently placed, nor are they connected to the internet. Goetzler et al (2012), show that central AC and heat pump FDD algorithms could save 0.40 quads of energy. In particular, improper refrigerant charge is the most important fault to be addressed.…”

Not-in-kind cooling technologies: A quantitative comparison of refrigerants and system performance

“…Herms and Barbosa (2012) compared three portable coolers using NIK cooling technologies. Goetzler et al (2012Goetzler et al ( , 2014 prepared two comprehensive reports using a quantitative score considering the energy saving potential, cost/complexity, nonenergy benefit and other aspects to compare the NIK technologies. Elastocaloric cooling (or thermoelastic cooling), membrane cooling and magnetocaloric cooling were considered as high potential alternatives to the vapor compression cooling.…”