ASHRAE Energy Audits
by Dave Baker, Corporate Energy Director, Prime Healthcare; CSHE State Secretary
In this quarter’s CSHE eBulletin, I want to share about Energy Audits, and the different levels of inspections that can be done at your facilities.
ASHRAE Level I – Walk-Through Analysis or Preliminary Audit
What is a Level 1 audit? It is sometimes referred to as a “High-Level” or “simple walk-through audit” which is considered to be the basic starting point for understanding your building energy optimization. Expect the energy firm or auditor to ask your engineering staff to provide utility bills; operating data; as well as, scheduling a relatively quick walk through of the facility mechanical rooms.
The ASHRAE Level 1 audit is mainly for identifying potential energy efficiency measures/improvements, as well as, understanding the general building configuration and type of equipment in place.
Once the energy auditor completes the walk through of your site, expect the results of the preliminary, high-level, energy-use analysis for the entire facility, and a short report detailing the findings, which may include identifying a variety of recognizable efficiency opportunities. Usually this report does not provide detailed recommendations, except for very visible projects or operational faults.
The ASHRAE Level-1 audit is intended to help the energy team understand where the building performs relative to its peers; establish a baseline for measuring improvements; deciding whether further evaluation is warranted; and if so, where and how to focus that effort. The Level-1 also will outline the range of potential financial incentives available from Federal, State, Local, and Utility sources.
ASHRAE Level II – Energy Analysis Survey
The next step for most facilities is the ASHRAE Level-2 audit/assessment. The Level-2 project starts with the findings of Level-1 audit, and evaluates the building energy systems in detail to define a variety of potential energy-efficiency improvements. This should include the Building Envelope, Lighting, Heating, Ventilation, and Air Conditioning (HVAC), Domestic Hot Water (DHW), Plug Loads, and Compressed Air, etc. This study starts with a detailed analysis of energy consumption to quantify base loads, seasonal variation, and effective energy costs. From there, the study should include an evaluation of lighting, air quality, temperature, ventilation, humidity, and other conditions that may affect energy performance and occupant comfort. The process also includes detailed discussions with Administrative Team, and Facility Director/Manager, to explore potential problem areas, and clarify financial and non-financial goals of the program.
The Level-2 audit should result in a clear and concise report and briefing with your whole team describing a variety of Energy Efficiency Measures (EEMs) including no- and low-cost measures, modifications to system controls and building automation, operational changes, and potential capital upgrades. The findings should include general costs and performance metrics, as well as, a means for the Owner to evaluate the EEMs and decide how to proceed with implementation.
Many of the EEMs revealed during the ASHRAE Level-2 audit can be implemented quickly with rapid or immediate financial payback to the hospital. Other EEMs will require more detailed analysis of benefit and cost and the other goals that are important to you. The audit should define next steps to accomplish this analysis and decision making. Sometimes it is through discussion with manufacturers or suppliers or other relatively simple means. For other EEMs, involving complex interaction among building systems and potentially large financial investments, it may be necessary to dig deeper into the building operation and also the human factors influencing performance. This is where the ASHRAE Level-3 audit becomes essential.
Some of the system upgrades or retrofits revealed by the Level-2 audit may require significant investments of capital, personnel, and other limited resources. Before making this level of investment, the Owner will want to have a much more thorough and detailed understanding of the benefits, costs, and performance expectations. This is the purpose of the “investment-grade” Level-3 ASHRAE audit. There may be only a few capital-intensive EEMs exposed by the Level-2 audit, or there may be dozens for larger facilities. Investment levels can range from tens of thousands to tens of millions of dollars. In most cases, since this cannot be clearly determined or accurately estimated in advance, the recommendation and scope definition for a Level-3 audit usually is an outcome of the Level-2 process.
ASHRAE Level III – Detailed Analysis of Capital Intensive Modifications
Last on the list, and usually very costly, is the ASHRAE Level-3 audit where they focuses on a “whole-building computer simulation,” where a computer program is used to very accurately model the way the brick-and-mortar building would respond to changes in the energy systems, whether those are major HVAC retrofits or architectural modifications to walls, windows, and roof. The ASHRAE Level-3 audit involves much more detailed data collection over the course of weeks or months. Data loggers typically will be placed temporarily to monitor the operation of pumps and motors, temperatures of affected spaces, lighting levels, switching behavior, and other factors. These data are used to calibrate the computer model of the facility, so that the computer model responds to inputs and changes the same way the building could be expected to respond.
This calibration is checked and validated by simulating a year or more of past, minute-by-minute climate conditions to see if power and energy usage in the model mirrors actual energy power and energy usage.
Once the three-dimensional computer model is responding like the real building, changes to energy systems can be simulated with very accurate results. Combining that process with construction-grade cost estimating supports informed investment decisions.
- Quick assessment of the building
- Building the energy benchmark
- High-level definition of the energy system, optimization opportunities, and outline of incentive programs available
- Detailed building survey of systems and operations
- Breakdown of energy source and end use
- Identification of EEM’s for each energy system
- Outlining priorities for limited resources, next steps, and identification of EEM’s requiring more thorough data collection and analysis
- Longer term data collection and analysis
- Whole building computer simulation calibrated with field data
- Accurate modeling of EEM’s and power / energy response
- Investment-Grade cost estimating, decision making support
Last thing before you embark with and energy audit for the building or portfolio of buildings, it is recommend to have a preliminary energy-use analysis to compare the Energy Usage Index (EUI) of each building with the national average and to identify both high and low energy performers. This is done using the Energy Star Portfolio Manager benchmarking tool. This analysis requires access to energy consumption and cost data for the last 12 to 36 months. Once this “benchmarking” analysis is completed a recommendation is made as to which buildings you should be auditing first and the type of audits to be carried out.
I hope this has given you a better understanding of the auditing process and what is expected of you.
Till next time, see ya in the boiler room!