Tracing Your Home's Ductwork
When I decided to implement zoning on my furnace I was faced with the task of mapping each furnace duct to its’ corresponding vent. A quick look at the 15+ metal arms extending from the furnace told me that this was not going to be an easy task. Fortunately, there is an easy and accurate method for tracing your ductwork… and it only requires a few basic tools.
What you need:
- Drill with 1/8” Drill Bit
- Essential Oil
- Duct Tape
Where to find what you need:
You probably have a Drill and Duct Tape lying around the house but, if not, you can find these at any home improvement store. Any size Drill Bit will work but you want to make as small a hole as possible to avoid unnecessarily damaging the duct.
The Essential Oil and Syringe is a little more difficult. I find amazon.com to be the best for selection and ease of ordering. Specifically, I use (both available from amazon):
- 5 ml Syringes with Blunt Tip Fill Needles
- Orange Oil Sweet
Ok, so now that we have our tools we are ready to start tracing those ducts!
Step 1 – Go to your thermostat and switch the fan (also called a blower) to ‘ON’. This will make the fan blow air even when the furnace itself is not on.
Step 2 – Locate a duct coming off of your furnace.
Step 3 – If the ductwork is metal, use the drill to make a small hole in the side of the duct. The exact placement is not critical but avoid making the hole at the bottom of the duct or the Essential Oil will drip out of the hole. If the ductwork is flexible then there is no need to drill a hole since the Syringe will easily puncture the flexible duct.
Step 4 – Insert the Syringe into the bottle of Essential Oil and draw approximately 1 ml of the Oil into the Syringe. The precise amount isn’t critical but don’t use too much since your house is going to smell like the Oil until it evaporates in the duct. I find that 1ml gives me a good, strong, traceable scent that dissipates within a few hours.
Step 5 – Using the Syringe, inject the Oil into the duct.
Step 6 – Cover the hole made in the ductwork with Duct Tape. For flexible duct the hole is probably small enough that taping won’t be required.
Step 7 – Now move around your house smelling the vents. The vent connected to the duct will smell like the Essential Oil.
Step 8 – Make sure to label the duct with a good description. Avoid labels such as “Billy’s Room” since this will mean nothing to a subsequent owner of the home.
Step 9 – Repeat the above steps for each duct you want to trace.
Step 10 – When finished tracing, make sure to go back to your thermostat and switch the fan back to ‘AUTO’. This will stop the fan from blowing air unless the furnace is on.
That’s all there is to it. This method is so much simpler than blowing smoke or fishing a tape through the ductwork. I hope it helps you as much as it did me.
© 2014 Timothy Marsh