This info is presented as a basic guide. Always consult a professional HVAC installer for your area if you have any questions. Every installation differs with respect to Building Codes, climate, orientation of the house, building materials used, and other factors. More information may be necessary. The guide also assumes that the system has sufficient excess capacity to supply a new addition.

1) First, determine square footage of room.
Length x Width = SF
(Example: For a 10' by 12' room: 10 x 12 = 120 SF)

2) Next, determine CFM of Air Needed to Supply the Room.
CFM means "Cubic Feet per Minute" and defines the amount of air flowing through a system.
One CFM of air is required to heat or cool 1 to 1.25 square feet of floor area.

(Example: A 120 sq. ft. room will require between 96 and 120 CFM.)
120 1.25 = 96     120 1.00 = 120

ROOM SQUARE FOOTAGE (Popular Room Size)

3) Then Pick Size of Metal Pipe Needed For The Room.
How much air does a given diameter of pipe carry?
The approximate CFM’s for various pipe diameters are as follows:

(Example: For a 120 sq. ft. room requiring approximately 96 - 120)
CFM’s (see above), use:
One 6" pipe (110 CFM) OR use a combination to total approximately 96 - 120 CFM

This information is provided as an example – every installation is different and should be designed by
a professional.

Size of Existing Air Supply Duct:
For efficiency of the overall system, the size of pipe leading from the main Air Supply Duct to the new room must be smaller in diameter. (This is called "reducing".) DETERMINE THE SIZE OF THE MAIN LINE YOU’LL BE "DRAWING" FROM, AND MAKE SURE THE LINE TO THE NEW ROOM IS SMALLER IN DIAMETER. The new supply line should always be drawing off a main air supply duct, not a branch line already dedicated to heating and cooling an individual room. If you must "draw" from a branch line, make sure to install dampers to help regulate the air flow.

Number of "Outlets" Into New Room:
For a better distribution of air, it may be desirable to have more than one supply register entering the room at different points. If so, factor this into determining the size of pipe needed.

Drawing From a Line Can Hinder Normal System Air Flow.
If hot or cold spots remain, you can install a damper to adjust air distribution to the required locations.

Here are some simple tips from our pros to help you along with your system installation, expansion, or addition.

IMPORTANT NOTE: This info is presented as a basic guide. Always consult a professional HVAC installer in your area if you have any questions.

Whether you are refinishing a room or adding a register, here are some suggestions to get you through the job. Keep in mind that every installation is different, so make sure to plan your job ahead of time to get the right product assortment.

1) Sketch out your layout to determine parts and quantities you will need.
2) Survey the job for obstacles to maneuver around.
3) Select the right size and type of duct and fittings.

Whether your existing system is round pipe, flexible duct, rectangular duct, or ductboard, you will need a take-off, starting collar, or tee saddle to begin your branch line. Your store will have a selection to choose from. Pick the proper size and type and you’re on your way.

• How Do I Install A Starting Collar or Take-Off?
• How Do I Use A Tee Saddle or Tee?

1) Trace the opening shape of the collar on the surface being used. (If you are adding an air supply register, make sure you tap into an air supply line.)

2) Pierce the metal surface using a drill or sharp tool. (A screwdriver and hammer can also be used.) Using snips, cut out entire opening. (If tapping into ductboard, cut opening with appropriate tool or knife.)

3) Insert collar, tabs first, into opening and fold down tabs inside.

4) Secure with sheet metal screws, duct tape, and/or sealant or mastic.

• How Do I Use A Tee Saddle or Tee?

A tee saddle is used in situations where you need to "tap" into an existing round pipe line. The tee saddle is a handy item for a room addition or when adding registers to an area. However, if a tee saddle is not available standard tee can be fabricated into a saddle.

To Install: 1) Spread over location of splice and trace opening onto pipe. 2) Pierce the metal surface using a drill, sharp tool, or screwdriver and hammer. Using snips, cut out entire opening. 3) Remount tee saddle over hole and secure with sheet metal screws, duct tape, and sealant or mastic.

Now that you’ve installed your starting collar, take-off, or tee saddle, you are ready to install your branch line. You may want to use round metal pipe or insulated flexible duct.

	ROUND METAL PIPE: Use 90 degree adjustable elbows for turns and corners. Secure with sheet metal screws, duct tape, and/or sealant.
	INSULATED FLEXIBLE DUCT: Pre-insulated, makes many turns without the use of an elbow, and is easy to install. Follow installation instructions on the carton. Make sure it is fully extended to ensure proper air flow. Leaving excess lengths will hinder air flow efficiency. Secure with flex duct straps and duct tape.	Flexible Duct Industry Association

First, look over the store selection of register boxes to make sure you get the correct configuration. Install your branch line to its register box location and attach the register box. Secure using sheet metal screws, duct tape, and/or sealant.

Second, once you have chosen the location for your new register box, mark and cut out the correct opening size. (If installing a floor register, make sure it is out of the way of normal foot traffic.) Next, be sure you have easy access to the location you have chose. Stay clear of electrical wiring and plumbing components in the wall or floor. If you find an obstruction, move the register to a better location. Then, mark off the area and cut out that area using a saber or keyhole saw.

Finally, from the basement, attic or crawl space, secure the register box. Now, all you need to do is match up the correct register grille size with your register box and your job is complete. (A 10" x 4" register box uses a 10" x 4" register, for example.)

The following are typical materials needed for most common installations:

Good Luck On Your Job!