Building Energy Resilience

As Eveline discussed in her last blog post on green banks, there are significant hurdles to gaining the trust and investment dollars of building owners to support energy efficiency investments. Because as efficiency providers we see these investments as certain, we expect owners to share our view and jump at the opportunity to invest in their property and get a great return. As Eveline mentioned, energy efficiency providers have a significant role in getting owners to adopt efficient practices. Here are five rules that can increase the success of energy efficiency programs and providers:

Outside air economizers are one of the most cost-effective, common, promising and troubled energy efficiency components you can find on a commercial air handling system. The concept is simple and beautiful – use outside air instead of expensive mechanical cooling when possible. When outside air is at the right temperature and humidity levels, turn off chillers, cooling towers and pumps, and bring in free air. In reality, however, while our firm has commissioned hundreds of outside air economizers (new construction and retrocommissioning projects), more than 50% of them have not functioned properly, causing significant energy penalties to the building operating costs.

Today ratepayers in many states are making large investments in energy efficiency. I am a passionate advocate for the need to invest in cost effective improvements to our building infrastructure. However, I am concerned that many efficiency programs are taking short cuts to attain near-term goals that will undermine the market’s ability to generate deeper and more lasting efficiency improvements over time.

Fun and profit can come in unexpected ways to energy efficiency engineers. A couple of months ago while at a jobsite conducting central air handler control testing, there was the inevitable wait-around time. So I stopped to take a look at a central heating hot water plant we commissioned a couple of years ago. It’s a basic system - an all-primary layout with two boilers and variable flow 7.5 horsepower pumps, controlled by a piping differential pressure (DP) control sensor located in a remote section of the distribution piping. The plant serves a few dozen single duct VAV box reheat coils. A pretty typical system.

A recent Test and Balance (T&B) report for a central air handler made me really question the value of some of our current T&B practices. The system was a conventional variable air volume (VAV) air handler with a return air fan and single duct reheat terminal VAV boxes. The purpose of the T&B process is to adjust and record air handler performance to achieve the specified maximum flow rates.

I recently visited the construction site for a high performance building project that is pursuing LEED platinum through design-build. The design-build project has all of the bells and whistles that you would expect for LEED platinum: CFL and LED light fixtures with daylighting, energy recovery for ventilation air, and high efficiency heat pumps for heating. Given such a fine collection of green building hardware, I was surprised to find that the high efficiency heat pump heating systems did not meet the state energy code! The particular problem is that the heat pump thermostats do not support temperature setback schedule controls (i.e., scheduled reduction in heating temperature setpoints when the building is unoccupied). A high performance building that does not meet code – how can this happen?!

It's easy to forget to reset your building management system (BMS) or a direct digital control (DDC) system seasonally. Did you overwrite your building management system to forgo night-time building temperature setup due to the hot summer this year? Many buildings had a hard time maintaining their cooler daytime temperatures and therefore cancelled the energy saving nighttime setup program. Forgoing this energy savings was worth the extra hours the building was able to maintain proper temperatures during the workday.

Recently, while reviewing the controls strategy for a large building’s condenser water pumps, I came across something I wanted to share – a simple opportunity for efficiency with no first cost. One, in fact, that increased pumping efficiency by 16% for a large portion of the annual operating hours. To find this opportunity, we considered the off-peak performance of the pumping system, not just its ability to meet peak loads.

A Performance Contract with an Energy Services Company (ESCO) can be a powerful tool to enable a business to improve the performance of their facility without requiring money upfront. An ESCO assesses a facility’s energy efficiency opportunity, manages the improvement implementation and guarantees the energy savings will be greater than the cost of the project. In my recent blog post, ESCO: Energy Efficiency Investment with No Money Down, I describe the process of a Performance Contract and state “the ESCO assumes the risk of under-performance.” In recent months, however, the cost of natural gas has decreased substantially and many existing Performance Contracts are seeing negative savings for which the building owners are responsible.