Case Studies

Dr. Energy Saver St. Louis Case Studies: Duct and Attic Insulation in St. Louis, MO for Optimal Comfort in a Once Unruly Home

Saturday, September 28th, 2013 by Melissa Bednarz


This St. Louis, MO homeowner first contacted Dr. Energy Saver St. Louis because the second floor of her home was uncomfortably hot during daylight hours, even while her air conditioner was continuously running. After a little online research, she stumbled upon a few videos on the Dr. Energy Saver website which lead her to scheduling a Complete Home Energy Check-Up. Dr. Energy Saver St. Louis’ BPI Certified Building Analyst, Chad Kues, uncovered the sources of this discomfort, including:

The home’s HVAC system and a portion of the ductwork were located in the attic of the two-story colonial style home. When the HVAC system and ductwork are located in the attic, the system has to work harder to produce conditioned air, and most of what conditioned air is produced leaks through the seams and joints in the ductwork.

The attic was insulated to an R-38 (roughly 13”) but was not properly air sealed. Penetrations for wires, plumbing and ductwork were allowing for conditioned air to escape into the unconditioned attic.

The two largest sources of air leakage from the second story into the attic were found to be the attic access door itself and the whole-house attic fan.


Jim and the crew first air sealed all of the attic’s ductwork with mastic. All of the seams were sealed in order to stop energy-wasting leaks and to improve the systems airflow down into the second story of the home. Then, the crew also built a dam around the HVAC system to prevent the blown attic insulation from settling around the unit. Blown insulation is very deep and makes navigating an attic nearly impossible. A catwalk was also built to allow for HVAC service technicians to access the equipment.

The crew also completed a complete attic air seal, which involved sealing all accessible top plates, chases, registers, plumbing and wiring with one-part foam. Once air sealing was completed, soffit vent baffles were installed, providing ventilation to the attic as well as preventing the insulation from filling the soffit. An additional four inches of blown cellulose was added, bringing the R-value up to an R-49.

Last but not least, Jim and the crew created a custom sealed and insulated attic hatch covering. Before their work, the access door did not close properly, and there was no seal to keep the conditioned air on the second floor. This attic hatch was custom made on site to fit the access perfectly and stained to match as closely as possible. The crew also disconnected the unused whole-house attic fan, sealed the opening and covered it with blown insulation. Where once the opening to the whole-house attic fan acted as an “open window” into the attic, there is now drywall, to be finished like the rest of the second story’s ceiling.

Project Summary

Installing Contractor: Dr. Energy Saver St. Louis

BPI Certified Building Analyst: Chad Kues

Production Foreman: Jim Jones

Services Utilized: Attic air sealing, air sealing ductwork, blown cellulose insulation, ventilation baffles, custom built attic hatch, insulation dams, attic catwalk

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Dr. Energy Saver St. Louis
524 Vandalia Street
Collinsville, IL 62234