If you compared your January gas bill to last year and winced, you’re not the only one. Energy costs in northern Illinois have moved up over the past few seasons. Cold snaps didn’t help.
But there’s a less obvious reason your bill might be running higher than it should. The duct system itself.
How Much Energy Leaky Ducts Actually Cost
The Department of Energy’s Energy Saver site has a page on duct losses that’s worth reading if you haven’t. They make the point clearly. Leaky ducts can lose a significant share of the heat your furnace produces before it ever reaches the rooms you’re trying to warm. Energy Star puts the typical figure around 20% efficiency loss for systems with leaky or poorly insulated ductwork. That’s heated air, paid for, going into your attic or crawl space.
Why Northbrook Homes Are Especially Vulnerable
Northbrook has a lot of homes where this matters. Two-story colonials with long runs of ductwork. Finished basements where some of the trunk line is exposed. Older retrofits where the air path travels through unheated zones. Any of those situations can mean money walking out of the system.
What the Symptoms Look Like
Buildup inside the system adds another layer. Heavy dust and debris narrow the effective opening. The blower has to work harder to push the same volume of air. Static pressure goes up. The system runs longer per cycle. That extra runtime shows up on your bill.
So how do you tell if your system is part of the problem?
A few signals. Rooms that never seem to get to the thermostat setting. Vents that feel weak even when the system is clearly running. Whistling at the registers. Visible dust around the supply boots. Heating bills that have crept up faster than the rate increases would explain.
Air Duct Cleaning and HVAC Efficiency in Northbrook
The DOE recommends having a qualified professional handle any ductwork changes or repairs. Sealing supply ducts. Insulating runs that travel through unheated space. Checking that the return side is actually pulling air the way it should. None of that is a DIY project for most homes.
For Northbrook homeowners who want to figure out where the system is losing efficiency, a real assessment is the place to start. Here’s a local option for air duct cleaning in Northbrook. They’re NADCA certified, which matters for any work that involves the ductwork itself.
There are smaller steps that help too. Make sure no furniture is blocking the supply registers. Check that the basement returns aren’t covered by storage. Replace your furnace filter on schedule. Set the thermostat fan to “auto” rather than “on” when the system isn’t actively heating. Small adjustments, but they add up over a winter.
Other Places to Check
It’s also worth checking insulation on any duct sections that run through unheated space. Crawl spaces. Garage walls. Unconditioned attics. If the insulation has been pulled away, gnawed on, or wasn’t there to begin with, you’re paying to heat air that loses warmth before it gets to the room.
A blower-door test or duct-leakage test, run by a qualified technician, will tell you exactly where the system is bleeding. Some utilities in Illinois offer rebates or incentives for that kind of assessment. It’s worth asking what’s available before you pay out of pocket.
The hard part is that none of these symptoms show up as one big problem. They show up as a little more dust, a little colder in the back bedroom, a slightly higher bill each month. The system keeps working. It just works harder than it should.
If you’re looking at a heating bill that doesn’t match what you remember from a few years ago, the ductwork is worth checking before you start thinking about a new furnace. Sometimes the issue is upstream of the equipment. Fix that first and the whole system gets easier to run.
