Why Your Leaky Ductwork Is Costing You Money (And What You Can Do)

The A/C experts at Houston’s Richmond’s Air explain the costs of leaky ductwork

We all know that a leaky hose costs us money. The water runs out of the hose’s perforations and we’re suddenly paying for water that’s dripping somewhere it shouldn’t be.

But did you know that your home’s ductwork might be far more leaky and costly than a washed up old hose? These metal pathways carry the conditioned air from your air conditioner (or heat pump or furnace) to the vents in your home where the air is distributed.

Often times this ductwork can have lots of leaks, especially in older homes. These leaks release the conditioned air into unimproved spaces like your basement, crawl space or attic. When you have leaky ductwork, you’re basically paying to heat spaces that you don’t use.

And you’re paying a surprisingly big price. According to Energy Star, leaky ductwork can lower a furnace’s efficiency by up to 20%. The good news is that if you’re a do-it-yourself kind of person, sealing your leaky ducts can be a fairly easy and cheap upgrade that can save money in the long run. It can also improve your indoor air quality since your ductwork won’t be picking up dirt and debris from unimproved spaces along the way.

If you want to seal your ducts, here are some general tips from your local AC & heating repairman to get you started:

1. Check Your Ductwork: Go into the space where your ductwork is located (attic, basement or crawlspace). If your ductwork isn’t wrapped in insulation, there’s a good chance it’s also not properly sealed. If the space feels comfortable, you’ve probably got some leaks. If the ductwork seems accessible, you can proceed.
2. Gather Your Supplies: You’ll need a few things for this project. You can use plastic wrap and duct tape or wide tape patches to seal off vents while looking for leaks.  A smoke pencil will help you find leaks- it costs about $50.00. You’ll also need mastic, foil-backed tape, and R6 foil-face insulation wrap. You can find all of these supplies at your local home improvement store.
3. Find and Seal leaks. You’ll use your wide tape strips to cover ducts and then turn on your air conditioner. Using the smoke pencil, you’ll follow the ductwork. If the smoke from the pencil blows sideways, you’ll know you have a leak.  Focus primarily on areas near the furnace, at the registers, and on air supply ducts — all areas where leaks are more costly.

   In these areas, use the mastic to completely cover the seams and holes that are leaking.  You can apply mastic with a paintbrush or with a gloved hand.  Don’t use duct tape to seal ductwork, and remove any duct tape you find along the way and replace it with foil-backed tape or mastic. Duct tape doesn’t prevent air loss.

4. Insulate Your Ducts: After you’ve found and sealed most of the big leaks, you’ll want to wrap your ductwork with R6 foil-backed insulation and seal the insulation with the foil-backed tape. Insulating your ductwork helps reduce energy loss, further improving your air conditioner’s efficiency.

Sealing ductwork is a relatively inexpensive energy upgrade that can help lower your cooling and heating bills in the future.

Visit our blog if you want to learn more about other energy upgrades to your home, including how to insulate your attic and the savings associated with programmable thermostats.