The “What is that Funky Smell?” Home
“Nothing is more memorable than a smell. One scent can be unexpected, momentary and fleeting, yet conjure up a childhood summer beside a lake in the mountains.”
— Diane Ackerman
A real estate agent contacted Home Energy Solutions after prospective buyers noticed an unexplained odor in a home they were considering purchasing. We were asked to identify the likely source and recommend the corrective work that would be required.
Evaluating an Unexplained Odor Before a Home Purchase
Because our initial information came from the buyers’ real estate agent, the assessment began with an on-site investigation. The odor was strongest on the first floor of the two-story home.
We inspected the crawlspace and HVAC equipment and evaluated possible air pathways between the crawlspace and the conditioned space above. Because the home was more than 15 years old, our testing focused on three likely contributors:
Leaking return ductwork could pull contaminated crawlspace air into the HVAC system and distribute it throughout the home.
Duct leakage from the second-floor system in the attic could depressurize the home and draw unconditioned air from the crawlspace and attic.
Aging or poorly sealed HVAC equipment in unconditioned spaces could allow warm, humid air to contact cold surfaces, creating condensation and conditions favorable for mold growth.
Sources of the Odor Identified During the Assessment
Mold Contamination in the Aging HVAC System
The HVAC system was approaching the end of its service life, and the ductwork contained extensive mold contamination. Based on the assessment, replacing the aging HVAC system and contaminated ductwork—along with correcting the contributing moisture and air-leakage problems—would address the source of the odor.
Crawlspace Air Leakage
We recommended air-sealing the crawlspace to reduce the uncontrolled movement of humid, unconditioned air into the home. Limiting these air pathways helps prevent moisture, pollen, vehicle exhaust, outdoor pollutants, and additional heat from entering the conditioned living space.
Condensation and Rust at Supply Registers
Rust on the metal supply registers indicated condensation caused by inadequate insulation and air sealing around the supply boots. We recommended insulating and sealing these areas to prevent warm, humid air from contacting cold metal surfaces. Bathroom ventilation also needed to be evaluated because insufficient exhaust can contribute to excessive moisture and mold growth.
The Outcome: An Informed Home-Buying Decision
Home Energy Solutions identified the likely sources of the odor and provided a report detailing the corrective work the home would require. The prospective buyers could then evaluate the expected costs, scope of remediation, and possibility of additional problems before committing to the purchase.
Ultimately, they decided not to buy the home. The assessment gave them the information needed to avoid an unsuitable purchase, and their real estate agent has continued consulting with Home Energy Solutions when clients need a clearer understanding of a property’s HVAC, moisture, or building-performance concerns.
