Posts in Category: engineering

How To Avoid Ambiguity During the Construction Process

Mission Critical Commissioning: The Commissioning Plan

Often times the process of commissioning can be an ambiguous event that can have a different meaning for the variety of players involved on the project (e.g., owner, design engineer, contractor, etc.) Developing a commissioning program and documenting it in a commissioning plan helps clear up a lot of that ambiguity in order for all contractors, the commissioning team, the design team and the owner to understand the requirements and determine the expectation level for the project. The commissioning plan ensures that everyone agrees that the project will operate in accordance with contract documents and approved scope of work. The commissioning plan will highlight important general project information (location, building type and the construction period), critical abbreviations and definitions, identifies which systems or components are being commissioned and also identifies the project team members involved (including their contact information). The commissioning plan intends to focus on the commissioning process throughout the various phases of a project: design phase, construction phase, acceptance phase and post acceptance.

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The Value of the Building Envelope Commissioning Design Review Process

­­­The Value of the BECx Design Review Process.

As with most things in the construction industry, it is always easier (and less expensive) to fix something on paper than to wait and have to remediate issues in the field. This is even more evident when dealing with Building Envelope systems, due to the nature of how the systems are untimely procured, developed and installed by the contractors involved. 

The name of the game when it comes to the development and realization of envelope components from the designer’s perspective is “defensible design”.  This is defined as - all details shown on the Contract Documents can be built to meet the design aesthetic set forth, but may be resolved in a variety of ways by the subcontractor performing the work. Given that the majority of systems being designed in an envelope are based on a performance specification, the ultimate final responsibility of the work is on the contractor performing the work.

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Engineers Week: Inspiring Youth to Pursue Engineering

John Lutz, Engineering Manager

Do you ever stop and think about how everyday technologies make our lives easier and make our world work? How does a cell phone allow me talk to my friends on the opposite side of the world? How does a plane that weighs over a hundred tons fly through the air and let us cross continents in a matter of hours? How can my microwave turn hard kernels of corn to crunchy pieces of popcorn? We can look all around us and see ideas in motion that serve a purpose; these ideas have one thing in common, engineering. Engineering principles and applications are at play in all human innovation.

In our world, it is very easy to take all these technologies and innovations for granted, if people don’t take the time to understand the engineering or the science behind them, the knowledge could be lost. Young people taking an interest in engineering and turning that interest into a thirst for knowledge is what propels our world forward.

For parents and adults, taking the time to share what you know and help inspire the young people in your life, could be the difference between making science and engineering something that is intimidating or something that becomes a passion.

For professionals or individuals in the engineering fields, take the time, reach out, and find a youth group or STEM program in your community and volunteer your time and experience. The task is simple, do not be daunted by wondering if you’re “expert enough” to teach others; a lifelong passion can be inspired by prompting a child to ask the simple question of “what if?”

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The Relationship of BECx to LEED V.4

LEED Version 4 has recently put the spotlight on Building Envelope Commissioning (BECx), in a good way. In the event your project is pursuing the credit associated with “Enhanced Commissioning”, you will be required to retain a BECx Agent, and quickly. BECx has been introduced to ensure the performance of the enclosure is coordinated with all related building systems, and to increase the overall energy efficiency of the building.

Some of the key factors associated with the new version are highlighted below:

  • Minimum Requirements for Exterior Enclosure.
  • Enhanced Commissioning Credit, BECx Agent during DD Phase.
  • Enhanced Commissioning Credit, BECx Agent responsibilities throughout the project.
  • Enhanced Commissioning Credit, Provide Post Occupancy Review and Support.
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High Performance Building Envelope



By: Robert Golda, Building Enclosure Associate

As building codes and energy codes continue to advance, especially as they are beginning to align with the latest versions of ASHRAE 90.1, the requirements for higher performing exterior envelopes is becoming the norm on many buildings across the country. 

With more stringent U-values, and much lower Solar Heat Gain Coefficients (SHGC) for fenestration systems, the cladding industry is quickly reacting by providing more high performance systems for the typical building stock. In addition, strong research into the effectiveness of air barriers, and the demonstrated cost savings when they are properly designed and installed, continues to highlight the importance of the building envelope and its roll in energy performance.

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Variable Refrigerant Flow (VRF): Growing Trend Explained

VRF

By: Thomas Conn, Field Engineer, NYC Office

Introduction
Variable Refrigerant Flow, commonly referred to as VRF, is a method of heating and cooling spaces that is quickly gaining acceptance and popularity in the United States. Although VRF, which uses refrigerant in either a subcooled liquid or superheated vapor state to heat and cool spaces, was invented in Japan in 1982, it was only introduced to the United States in the 2000s. This “new” technology spread quickly across several large markets and is now a viable option for heating and cooling in almost any application.

What is VRF?
The concept of VRF is a rather simple, and literal, expansion of the tried and true refrigeration cycle. It should be explained by comparing it to a traditional chiller system first: instead of the evaporator being a heat exchanger where the refrigerant cools down water to be pumped through terminal units to cool a space, the refrigerant flows through coils inside an “Indoor Unit” which blows air taken from the conditioned space over the coils (which are acting as the evaporator), cooling the air and heating the refrigerant. The refrigerant travels back up to the “Outdoor Unit” to be pressurized by the compressor and reject heat to the atmosphere in the outdoor unit’s coils (this takes the place of a condenser in a traditional system)...

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HEA is Providing Commissioning Services for the Tappan Zee Bridge Replacement Project

 Horizon Engineering Associates, LLP (HEA) has been hired by Tappan Zee Constructors, LLC (a consortium of some of the world’s best-known and most highly-regarded design, engineering and construction firms) to provide Independent Quality Assurance Commissioning Engineering services for the $3.98 billion Tappan Zee Bridge replacement project.

HEA will be providing commissioning services for all bridge and facility systems (maintenance and state policy facility). Building systems include bridge systems (power, lighting, intelligent traffic systems, structural health monitoring, security, network communication, radio and facilities systems), building automation systems, mechanical, electrical and plumbing systems. HEA’s services will provide documented confirmation that building systems function in accordance with criteria set forth in the project documents to satisfy the owner’s operational needs.

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Reducing Duct Leakage in Existing Buildings: Aeroseal Technology


Written by: Nicholas Neiley, Project Engineer

Unchecked, duct leakage can be a significant added cost in any ventilation system; particularly existing laboratory buildings. The cost to condition and deliver outdoor air can range from $7 to $12/cfm per year depending on local climate and utility costs. This can make any leakage on 100% outdoor air systems extremely expensive. During a recent controls upgrade project at Cornell University, significant utility savings were captured through the use of a duct sealing technology called Aeroseal.

The Baker Lab project initially included an upgrade the control system of a modern DDC system to address ongoing maintenance and energy efficiency concerns. During testing, balancing, and commissioning, it was identified that the existing ductwork systems had significant leakage, up to 30% in some locations. This was largely due to the existing ductwork systems utilizing clay flues in the original 1921 building construction. An Aeroseal vendor was contracted to seal all the exhaust risers and most supply risers.

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Identifying and Fixing a $250,000 blunder

By: Scott Lance, EBCP, LEED AP O+M, Senior Project Engineer

Overview:

  • HEA was hired to provide commissioning services for a higher education dormitory.
  • During the test and balance (TAB) period of the project, it was discovered by the TAB contractor and HEA that the dual temperature system was unable to be balanced. It was also noted that the extremities of the two wings of all three floors could not provide any heat to the occupied dorm rooms. This resulted in parents pulling students out of school due to the dorms not being able to be heated and 85% redo of the building piping systems - a $250,000 error!

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