VENTILATION and electrical penetrations

Openings and penetrations associated with ventilation systems, electrical equipment and devices or associated with chases (that is, channels for drain-pipes, wiring and chimneys) are common air pathways.

These penetrations, when linking conditioned and unconditioned spaces, should be fixed, since they will be a source of problems and a cause of high energy bills.

Sealing Hvac and Electrical Penetrations

What to seal

The image above (from DOE) shows some of the penetrations associated with mechanical ventilation systems or electrical and chase openings, and where to seal.

Any plumbing or any electrical wire penetration through drywall should be sealed with foam or caulk. Electrical switches, outlets and circuit breaker boxes to drywall should be caulked or foamed (a simple way to fix the problem is to remove the faceplate, add a foam gasket and replace the plate.)

Cracks or openings related with medicine cabinets, light fixture boxes, bath and kitchen ventilation fans (or whole-house fans) should also be sealed (use spray foam or house-wrap tape to seal whole-house fans), as well as penetrations due to combustion equipments.

Sealing Products

Electrical wire, plumbing, and HVAC/ventilation penetrations should be sealed with caulk or spray foam.

Wiring, knockouts in electrical boxes or outdoor mounted boxes to the exterior sheathing demand specific caulks. 

Pay special attention to the risks that fixtures and electric components may put. Seal the space between the fixtures and drywall with proper caulks.

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