DIY Network

Cleaning and Sealing an Air Conditioning Air Handler Cleaning up plumbing-related smells can require installing new ductwork. From "Finders Fixers" episode DFFX-102

Host and home inspector Wally Conway is helping homeowners Kate Woods and James Donaldson get rid of the stench (caused by a plumbing failure) in their house by showing them how to take apart the A/C air handler and clean out the coils and squirrel cage. They learn how to rebuild the air handler and begin to install new ducting, which is hung from the floor joists in the crawlspace under the house.

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Materials:

wrench
vacuum
antimicrobial cleaning solution
garden hose
insulated duct board
plastic rib
aluminum foil
mastic adhesive cement
paint brush
heavy duty air filter
air duct
plastic ties
scissors

Note: This project requires intermediate to advanced air-conditioning repair skills. Also, check with the manufacturer of your unit regarding detailed repair and warranty information.

1. Shut down the A/C unit outside and retract the coolant in the refrigerant line to avoid any spills. Only then can the refrigerant line be detached inside. Also disconnect the condensation drain line at the air handler.

2. Turn the power off at the electrical panel and disconnect the electrical at the air handler. Next, remove the fan system (also known as the squirrel cage) and remove the coil. Lastly, remove the air handler casing (figure A).

3. Begin cleaning the air handler by first vacuuming away dirt caked on the inside of the air handler casing.

4. To clean the coils, use an antimicrobial solution. When the solution turns the coils white, thoroughly rinse them with a garden hose. Follow the same procedure to clean the fan system (squirrel cage) (figure B).

Figure A

Figure B

5. The air handler can now be put back together. Cut new insulated duct board to size so it tucks in and fits snugly around all sides of the handler. Tape all seams with aluminum tape and burnish with a plastic rib. To further seal each seam, paint on a coat of mastic adhesive cement (figure C) (figure D).

Figure C

Figure D

Figure E

6. Replace panels back onto air handler. Reattach coils and squirrel cage. Reattach the refrigerant line as well as the condensation drain line at the air handler.

7. Replace the old filter with a new heavy-duty filter (figure E).

Note: Filters should be changed approximately once a year. If you have pets or allergies, you may want to change the filter every six months to ensure a fresh system.

8. As a final step, install new ductwork in the attic above the air handler, using plastic ties to hold the work in place, ensuring attic air won’t be able to get in from above.

RESOURCES :

Filtrete heavy-duty air filter
Website: www.3m.com