Brass Component Failures

DonanEngineering Appliance, Product & Component Failures, Component Testing, Engineering Manager, Water Losses

Brass failures commonly occur with plumbing components used in the supply of domestic water in residential, commercial, and industrial applications.  The mechanical failure of these brass components is often misdiagnosed or misunderstood by many who attempt to identify the source of the failure.  To more thoroughly and accurately diagnose the cause of a brass failure, it is important to understand …


Repairing Atlas Chalet Shingles: Donan’s Technical Position

DonanEngineering Articles, Commercial & Residential Roofing, Forensic Engineering, Hail and Wind

The Atlas Chalet shingle was a three-tab, fiberglass mat asphalt shingle with an additional applique layer of asphalt and granules over the shingle tabs.  The applique layer was for decorative purposes only to give the appearance of a dimensional-style shingle.  Atlas Chalet shingles had a 30-year limited manufacturer’s warranty and a five-year wind warranty for up to 80-mile-per-hour wind speeds.  …


Thermal Bridging and Air Sealing

DonanEngineering Articles, Featured, Forensic Engineering

In the process of building our first house, my wife has called me “the builder’s worst nightmare.”  And in some ways, she’s correct.  In other ways, I’m my own worst nightmare.  However, I’m only using the knowledge I have gained as a forensic engineer to limit thermal bridging and air leakage. In older conventional construction (such as our current house …


Understanding How Hail Damage Affects Commercial HVAC Units

DonanEngineering Articles, Featured, Hail and Wind, HVAC Forensics, HVAC Managers

There are many types, manufacturers, and sizes of commercial HVAC systems which can make it difficult to create general guidelines for repair procedures and estimates for hail-damaged units. This guide uses the most common “light commercial” rooftop units (RTUs), which are 5-tons, 7.5-tons, and 10-tons in capacity, for estimating time to repair or replace. Defining Hail Damage to an RTU …