Thermwell AC12H A/c Weather Seal Kit 3-piece Foam

Product Description

The THERMWELL AC12H is a three-piece urethane foam weather seal kit designed for window-mounted air conditioner installations. The kit includes two L-shaped foam strips measuring 1-7/8 inches by 33 inches and one flat foam strip measuring 1-1/2 inches by 33 inches. Together, these strips seal the gaps between the A/C unit and the window frame or sill, blocking outside air infiltration, moisture intrusion, and insects. HVAC technicians and window A/C installers use this kit to complete a professional, energy-efficient installation that protects the window sill surface from condensation damage.

This kit is suited for standard residential window air conditioner installations where the unit sits in a single- or double-hung window opening. The foam conforms to the contours of the window frame and unit chassis, filling irregular gaps that rigid materials cannot address. It is appropriate for new installations as well as reinstallation of existing units at the start of the cooling season.

Key Features

• Three-piece kit includes two L-shaped strips and one flat strip for full perimeter coverage
• Urethane foam construction conforms to irregular gaps between the A/C chassis and window frame
• L-shaped strips measure 1-7/8 inches by 33 inches for vertical and horizontal sealing surfaces
• Flat strip measures 1-1/2 inches by 33 inches for sill-face application
• Protects window sills from condensation and moisture damage caused by operating A/C units
• Blocks outside air, drafts, and insects around the installed unit perimeter

Compatibility

Designed as a general-fit weather seal solution for standard residential window-mounted air conditioning units installed in single- or double-hung window openings.

Installation Notes

Installation does not require electrical shutoff but the A/C unit should be powered off and stable in the window opening before applying the foam strips. Clean and dry all contact surfaces before pressing the foam into place to ensure proper adhesion and an airtight seal. A/C weather sealing work is typically performed by HVAC technicians or qualified service pros following the unit manufacturer's installation guidelines.