Recently I researched the “Roof Top Unit Challenge” which was created by the U.S. Department of Energy (DOE). What is the Roof Top Unit challenge? Launched in January 2011, the DOE released a design specification or commercial RTUs (Roof Top Units) with capacities ranging between 10 and 20 tons. RTUs built to match this specification are expected to have reduced energy usage by as much as 50% compared to a code compliant RTU. There is a large dependency on the building type and location of the RTU in relation to amount of energy savings. Since January 2011, top performing RTU manufacturers are working to design units that meet this specification. In this post, I will discuss what it takes for a unit to be part of the RTU Challenge and which manufacturers have models that are designed to meet this performance specification.
Over the past six months, I have been taking on a new role at Cx Associates as an owner’s Project Manager for a large organization in Burlington, VT. This has given me the opportunity to be part of a construction team - not as part of the commissioning firm, but rather by working for the owner in overseeing the project in its entirety. One of my current active projects is an HVAC mechanical upgrade in an office building known for occupant comfort issues. In this post, I will describe one of the difficulties we needed to overcome with this particular project, as well as a helpful tool that has been very useful for me as a Project Manager.
Topics: Building Cx & Design Review
After completion of an ASHRAE Level 2 Energy Audit, a building owner is faced with the question of how to move on to the implementation phase of the identified energy saving opportunities. The audit report provides estimates for annual energy savings for each opportunity, as well as the simple payback to help determine if the measure is financially feasible. However, the audit does not design a measure in enough detail that a contractor can accurately bid or install the measure so that the savings are realized. Therefore we suggest that the building owner hire a technical consultant (designer or commissioning engineer) to develop a bid document that details the design of the measure. This technical consultant must understand the owner’s goals and expectations for the project.
For both new building commissioning and existing building retrocommissioning projects, I always stress the importance of verifying that the claimed savings are realized through building performance monitoring (trending) using utility bills, sub-meter data, smart meters, or directly through a building management system (BMS). I also encourage you as a building owner to use a benchmarking tool, such as Energy Star Portfolio Manager, to monitor the overall energy usage of the building over time. While studying for my LEED Green Associate (GA) exam, I came across a new performance monitoring system released last year by USGBC called the LEED Dynamic Plaque. My aim in this blog post is to introduce the new USGBC platform and describe how it can help you to monitor your commercial building’s performance and work towards a more efficient and sustainable building.
Today there are a multitude of energy metering devices, (or data loggers), available to enable the analysis of building systems functionality. There are many different types of data loggers, each with a different purpose. To get the most from your building using energy metering, you need to narrow your options with your overall goals in mind. Before we install meters on a system, whether it’s an electrical system, HVAC system, or domestic hot water system, we first determine what type of data we need and what the data will be used for. With this information, we put together a metering plan that will produce the data necessary for the analysis. For this blog post, I am going to provide two specific examples of systems/equipment we metered, including why we were performing the metering, how we did it (what types of meters), and what the findings were. Both of these examples showed the equipment being metered was not working as intended.
In a previous blog post, Jennifer Chiodo discussed why energy benchmarking is beneficial for everyone, whether it’s for a residential building or a commercial building. Benchmarking allows you as the building owner to not only understand how your building is doing from an energy standpoint over time, but it also compares the building to other similar buildings in its class. Using the Energy Star Portfolio Manager online benchmarking tool, you can monitor a building’s energy usage over time by setting goals and comparing the overall energy use intensity to a baseline year.
For a recent commissioning project, part of our scope of work was to test an emergency power system for a data center. Because this data center was a very important part of the client company’s work, the system and all components needed to work as intended by the design, and it was crucial that it be tested with all aspects involved before the data center was utilized. This was to ensure there would be no loss of power to the data center servers if any issues were identified. In order to properly test this mission critical system, we not only needed to understand how each component worked, but we also needed to put together full testing documents that included the relationship between all of the components. To make the entire process more fluent, we suggested a coordinated effort for creating documents and testing the system.
In a previous blog post, I discussed our process for constructing a scope of work to perform a campus water consumption analysis. At the time, we knew a minimal amount about the existing metering system. A site visit was conducted to allow us to put our eyes on each meter listed for the campus. After this was completed, we were able to provide helpful information to our client regarding the current water consumption and metering system as well as next steps for reducing their consumption using a greater level of water use monitoring.
When it comes to enjoying the many positive features of an enclosed parking garage, most users will not think about the type of ventilation system in place. But an enclosed parking garage poses an issue with carbon monoxide (CO), a very harmful toxic gas that is created when “fuels burn incompletely – most vehicles have an internal combustion engine where this occurs”. Known as a “silent killer,” CO has no odor or color, but can very quickly poison a person before they even sense anything is wrong. Because of this risk, it’s especially important to make sure there is a proper ventilation system in any enclosed area where there is a potential for formation of CO. In this blog post, I will discuss the pros and cons of two current system designs that are typically used. When an engineer designs a ventilation system for an enclosed garage, they carefully calculate how much CFM is required based on square footage and quantity of operating vehicles. Depending on climate and location, the applicable standard/code for ventilation must be carefully followed to ensure the minimum requirements are met.
In a recent blog post, “The Benefits of an ASHRAE Level 1 Energy Audit,” I discussed the process of performing an ASHRAE Level 1 energy audit, which is the first step in the LEED accreditation process for Existing Buildings (LEED EB). The Level 1 report is used to determine whether there is enough energy saving opportunities to proceed with LEED EB accreditation. In order to receive an energy credit in the official LEED EB application, however, an ASHRAE Level 2 energy audit is required. The Level 2 audit uses energy surveying and an engineering analysis to provide an even more detailed breakdown of how a building is performing; going deeper into the analysis of the Level 1 measures and identifying additional measures to improve the efficiency and functionality of the building. The Level 2 report details the opportunities to such a degree that actual decisions on implementation can be made and the LEED EB credit can be realized.