Heating and Cooling

NBI is working to create solutions for low-energy cooling system design, operations and maintenance. Project work includes:

Field Research Reports on an Indirect Evaporative Air Conditioner
NBI conducted lab and field technical assessments of eight Desert CoolAire™ prototype indirect evaporative air conditioners on behalf of NEEA and SMUD. Read or download the Executive Summary on the 2006 field research, the Complete Final Report on the 2006 research, or the 2007 Addendum on additional monitoring and equipment status.

Market Assessment of Evaporative Technologies
NBI completed a report on the range of evaporative, evaporative hybrid and evaporative condensing technologies for HVAC applications on behalf of Southern California Edison including: technologies, manufacturers, market applications and adoption factors surrounding evaporative approaches to cooling.

Rooftop Unit Group (RTUG)
Improving the operating performance of rooftop unit air-conditioners is the objective of a working group and field project conducted by NBI for Pacific Northwest electric utilities. This project is composed of four interdependent elements: 1) bench testing of economizer controls, 2) field testing of repair protocols, 3) devising an appropriate measurement and verification approach and 4) developing a savings prediction methodology based on prototypical buildings. The Bench Test Report on the field analysis is now available.

Hot Dry Air Conditioner Project (HDAC)
NBI is part of the Market Connections team on the CEC-PIER HDAC project. A 3–ton split and 5-ton package unit were re-engineered for optimum performance efficiency at 115°F with field tests on eight units. The tests showed that it was possible to reduce demand by up to 35% at the critical peak and energy use by 20%. The overall field test report and the report on the PG&E field tests are available. Results from 2007 cooling season field monitoring will be available in the fourth quarter of 2007.

Advanced Automated Commercial HVAC Fault Detection and Diagnostics Program (FDD)
NBI manages the Market Connections component of the CEC-PIER FDD Program, which focuses on two projects: 1) The Advanced Rooftop Unit (ARTU) integrates a range of “advanced” energy efficiency and control strategies in a 5-ton package unit. The list of features that would enhance field performance and a benefit-cost analysis has been finalized. The ARTU team is working with the CEE HVAC Committee and HVAC Industry Partners to support the adoption ARTU features. 2) Embedded Diagnostics for rooftop units represents a breakthrough in managing and optimizing the operations and maintenance of rooftop units through an integrated diagnostic sensor suite with a web-based user interface.

In June 2007 NBI organized the first FDD Roundtable held at the Western Cooling Efficiency Center (WCEC) and cosponsored by WCEC, the California Commissioning Collaborative and Architectural Energy Corporation. Attendees developed a set of action plans to increase the interest in, and use of, FDD tools for managing the ongoing energy and environmental performance of commercial HVAC systems. For details, read the Roundtable Summary and Notes.

Research

Field Monitoring of High Efficiency Heat Pumps
Howdy Reichmuth has coauthored a paper entitled Field Monitoring of High Efficiency Heat Pumps. This paper, prepared for presentation at the 2006 ACEEE Summer Study, contains detailed performance measurements of four modern high-efficiency heat pumps.

Indirect Evaporative Systems
We are leading a technical field assessment of a hybrid prototype (the Desert CoolAire) that combines indirect evaporative cooling with packaged Dx cooling and gas heating. Working on behalf of the Northwest Energy Efficiency Alliance and SMUD, the project has placed nine 5-ton package rooftop systems at commercial sites and is extensively monitoring the field performance and assessing installation and operational issues.

Review of recent commercial rooftop unit field studies in the Pacific Northwest and California
This report, prepared for the Northwest Power and Conservation Council, presents the aggregated results of four recent investigations into the efficiency and operational problems of packaged rooftop heating, ventilation and air conditioning units (RTU) and suggests recommendations for programmatic approaches to capture RTU savings potential.

• View or Print the Rooftop Unit Field Studies (.pdf – 86 KB)

Small HVAC Problems & Potential Savings Reports
This report was produced through the PIER Integrated Design Research project. It summarizes the problems found in the field surveys of 215 new small package rooftop HVAC systems and estimates the related energy impacts.

• View or Print the Small HVAC Reports (.pdf – 7.5 MB)

We've undertaken many research projects over the years. You can access our archives at research page.