Things You'll Need
Duct work distributes warmed air throughout your home from your furnace. This warmed air is dispensed into your living space through supply air registers. You can find these registers in your ceiling, wall, floor or in the baseboard space where your wall and floor meet. The duct work for baseboard diffusers actually penetrates the floor space right next to the wall but not the wall itself. These registers are the most inconspicuous option since they tend to blend into the room well.
Measure the duct opening in the floor. Your typical baseboard register will be larger than your duct opening, but using this reference will ensure you don't purchase a register that is too small.
Pick out a register that suits your needs. They come in a variety of styles and in sizes up to 48 inches long.
Position the baseboard register frame over the duct opening and lower it down to the floor. Try to center the duct opening in the register, if possible, to allow even distribution of air through the register.
Screw the baseboard register frame to the wall. Use a stud finder to ensure the screws are secured in a wall stud and not just drywall.
Place the baseboard register cover over the frame. Secure the cover to the frame with the provided screws. Most covers have one screw on each side.
Adjust the damper on the baseboard register to achieve the desired airflow into the room. The damper is adjusted by sliding the protruding handle on the front of the register either up or down.