Welcome to another post in our continuing series on how we, as HVACR technicians, can do our bit to improve the energy efficiency of our customers’ HVACR systems. If we incorporate this knowledge into our service and installation work, we’ll be saving our customers money and making their lives better and more comfortable, as well as contributing to the larger goal of wise use of limited and costly energy resources.
By Dan Linthicum
Changes to a building are usually made with the intent of improving performance or comfort. However, changes can have unexpected results. Here’s an example: in the 1970’s, the energy crisis prompted builders to significantly increase the amount of insulation installed in homes and commercial buildings. The anticipated results – which were achieved – were reduced energy use and increased occupant comfort levels. Unfortunately, there was a hidden cost – increased moisture accumulation! This led to accelerated mold growth and increased incidences of structural rot.
These undesirable changes came about because of ‘non-system’ thinking. No one stopped to consider the effect of additional insulation on other parts of the building system! Extra insulation was installed and the problem of increasing energy prices was considered to be solved. However, the exterior sheathing or siding became colder since the amount of heat loss from the home was reduced. Warm, moist air from the inside continued to migrate outward and condensed on these now colder surfaces. This led to the undesirable results of siding and paint failure, roof deck rot and increased mold and mildew growth, including growth in places never before affected.
Modern System Thinking
The System Approach: Each part of a building is viewed and recognized as an interacting and interdependent part of a unified whole. This is the backbone of Applied Building Science.
Every change in construction techniques and every new HVACR product introduced into a building must be evaluated to determine how it will affect the Building System.
How will it affect the flow of moisture, heat and air?
How will it affect the air quality or other aspects of the indoor environment?
How will it affect how the building interacts with the outdoor environment?
How will it affect the building safety and durability?
Remember, any changes made to a building can bring unexpected results. A system approach will help avoid the unexpected!
Building science professionals look at individual buildings as complete systems, rather than a collection of isolated parts. Research has proven that changing a single part of the building has an effect on the entire building system, sometimes positive and sometimes negative. Trends in changing out or upgrading equipment and building remodeling techniques come and go in response to new developments in technology, but positive and negative effects must be taken into account during the planning stages, with specific results matched to specific situations found in each building and environment. A ‘one size fits all’ type of thinking just won’t work anymore.
Want to learn more about how to treat a building as an interactive system?
Check out our course: 107 Principles of Building Science in our HVACRedu.net Master Catalog, then e-mail our Student Services department at email@example.com. Tell them “I want to learn more about Building Science!” and they’ll fix you right up.