Sheet Metal Services

Ductwork Failing? System Running But Rooms Still Uncomfortable?

Is your furnace or AC running constantly but one room stays cold in winter and hot in summer? Are you hearing rattles, whistles, or banging from behind walls when the system kicks on? Have your utility bills climbed steadily even though you haven't changed your thermostat settings? These are the signs of ductwork failure — gaps, leaks, collapsed sections, or poor original design that's dumping conditioned air where you can't use it. This isn't a problem you can fix with a new filter or a thermostat adjustment. It requires sheet metal expertise and access to the hidden pathways your air travels through.

Smith Heating, Air & Sheet Metal handles ductwork problems across Southern Illinois — from Steeleville to Murphysboro, Chester to Pinckneyville. We fabricate custom fittings, install new duct systems, and repair failures that other companies can't or won't touch. When your HVAC equipment is working fine but your home isn't comfortable, the problem is almost always in the delivery system. We fix the path the air travels, not just the machine that moves it.

Custom Sheet Metal Fabrication for HVAC Systems

Standard duct fittings come in fixed sizes and angles, but real homes don't cooperate with off-the-shelf parts. We get calls from homeowners who've been told their ductwork "can't be fixed" because the layout is too tight, the ceiling height is wrong, or the original installer used non-standard sizing. That's when custom fabrication becomes the solution. You might need a transition piece that drops from a 10-inch trunk line to an 8-inch branch while navigating around a floor joist, or a plenum box that fits into a mechanical closet with only 14 inches of clearance. Stock fittings won't work, and forcing them creates restrictions that choke airflow and make your equipment work harder than it should.

Custom fabrication starts with measurement. We're looking at the space available, the airflow requirements for each room, and any obstacles — plumbing runs, electrical conduit, structural beams. We take those dimensions back to the shop and fabricate the pieces from galvanized steel or aluminum, depending on the application. Galvanized is standard for most residential ductwork because it resists rust and handles temperature swings without warping. Aluminum is lighter and easier to work in tight retrofit situations, but it's more expensive. We cut, bend, and seam the metal to create fittings that match your system's exact needs, then seal every joint with mastic and metal-backed tape — never just foil tape, which fails in a couple years.

Common Custom Fabrication Requests

- Custom plenums for new high-efficiency furnaces that don't match old duct sizing - Transition boxes for zoning dampers in multi-story homes - Return-air boxes for additions where there's no existing return path - Flashing and vent caps for roof penetrations that won't leak - Odd-angle elbows and reducers for tight crawlspaces or attic runs

Custom work costs more than stock fittings, but it's the difference between a system that fights itself and one that delivers the airflow it was designed for. If your HVAC contractor has told you a layout "isn't possible," it usually just means it requires fabrication. When you're also dealing with duct repairs elsewhere in the system, custom pieces often become part of the solution — a proper transition eliminates the need for duct tape and wishful thinking. Whether your system needs a single custom fitting or a complete rework, our Sheet Metal Custom Fabrication services deliver the exact pieces your layout demands.

Professional Ductwork Installation for New & Replacement Systems

New ductwork installation happens in two scenarios: new construction, where there's no existing system, and full replacement, where the old ducts are so compromised that patching them is throwing money away. In new construction, we're designing the layout from scratch based on the home's square footage, insulation levels, window placement, and the heating/cooling load for each room. Manual J calculations tell us how many BTUs each space needs, and Manual D tells us what size ducts will deliver that airflow without excessive velocity (which creates noise) or insufficient pressure (which starves distant rooms). Most comfort complaints in newer homes trace back to ductwork that was sized by guesswork instead of load calculations.

In replacement scenarios, we're usually dealing with ductwork that's 30, 40, sometimes 50 years old. Homeowners often don't realize their ducts are failing until they replace the furnace or AC and the new equipment doesn't perform any better than the old one. That's because the delivery system is still broken. A high-efficiency furnace can't overcome ductwork that's leaking 30% of its air into unconditioned spaces.

Signs You Need Full Ductwork Replacement

- Visible rust holes in basement or crawlspace ducts - Sections that have collapsed or separated completely - Asbestos-wrapped plenums near old furnaces (common in homes built before 1980) - Flex duct sitting in standing water or showing visible mold growth - Rooms that have never been comfortable no matter how many repairs you've tried

Our installation process starts with layout design. We identify the best path for trunk lines — usually through a basement or attic — and map branch runs to each register. We avoid long flex-duct runs, which create friction and reduce airflow; rigid sheet metal is always the better choice for main trunks. We size supply ducts based on CFM requirements for each room and make sure return-air pathways are adequate, because undersized returns choke the system and cause pressure imbalances. Every seam is sealed with mastic, every joint is screwed (not just taped), and insulated ducts in unconditioned spaces get wrapped with foil-faced insulation to prevent condensation and heat loss.

The cost difference between a cheap duct job and a proper one shows up in your utility bills within the first year. Leaky ducts waste 20-40% of the energy your furnace or AC produces, and undersized ducts force your equipment to run longer cycles, which shortens its lifespan. Catch it during installation, and you've got a system that will perform efficiently for 20+ years. Try to patch a bad layout later, and you're spending money on fixes that never quite solve the problem. If you're installing a new HVAC system or replacing failing ductwork, our Sheet Metal Ductwork Installation team ensures your home gets the airflow it was designed for.

Duct Repair & Maintenance to Restore System Performance

Most duct problems announce themselves indirectly — a room that used to stay comfortable now runs hot in summer or cold in winter, utility bills that have climbed even though you haven't changed your thermostat habits, whistling or rattling from the vents when the system kicks on. The furnace or AC runs constantly but never quite reaches the set temperature. Homeowners almost always suspect the equipment first, but nine times out of ten, the problem is in the ductwork.

Common Duct Failure Points

- Seams that have separated due to thermal expansion and contraction, especially near the furnace plenum where temperatures swing the most - Flex duct sagging or kinked in the attic or crawlspace, restricting airflow to specific rooms - Rodent damage — mice and squirrels chew through flex duct insulation and gnaw holes in thin-gauge metal - Rust-through in older galvanized ducts, particularly in damp basements or crawlspaces with poor vapor barriers - Disconnected ducts that got bumped during plumbing work or storage rearrangement

Our diagnostic process starts with a visual inspection of accessible ductwork and a blower-door test if the homeowner wants to quantify leakage. We're looking for visible gaps, disconnected sections, crushed or kinked flex, and any signs of moisture intrusion — rust, mold, water stains. We also check dampers to make sure they're opening and closing properly, because a stuck damper can starve an entire zone. Repairs depend on what we find. Small gaps and seams get sealed with mastic and foil-backed tape. Larger holes or rust-through sections get patched with sheet metal and sealed. Severely damaged sections — collapsed flex, rusted-through rigid duct — get replaced entirely, because patching compromised metal is a temporary fix at best.

The trade-off conversation we have most often: repair versus replacement. If your ductwork has multiple failure points, scattered leaks, and poor original design, patching it will cost you $800-$1,200 and buy you a few more years, but you'll still have an inefficient system. Full replacement might run $3,000-$5,000 depending on the size of your home, but you'll gain 20-30% efficiency, better comfort in every room, and no more emergency repairs when another seam fails. We'll walk you through both options with real numbers, because the right answer depends on how long you plan to stay in the home and whether your equipment is also near the end of its life. Sometimes Sheet Metal Ductwork Installation makes more sense than another round of patches, and we'll tell you that straight. When ductwork problems are cutting into your comfort and efficiency, our Sheet Metal Duct Repair & Service work gets your system back to delivering the performance it should.

How Smith Heating, Air & Sheet Metal Works

When you call us for ductwork issues, we show up with the tools to diagnose the problem and the sheet metal skills to fix it right. That combination matters, because a lot of HVAC companies can service equipment but don't have in-house fabrication capabilities — they'll identify a duct problem and then subcontract the metalwork to someone else, which adds time and cost. We handle both under one roof.

Our process starts with a walkthrough. We'll inspect your ductwork in the basement, attic, or crawlspace, looking for visible damage, disconnected sections, and poor original design. If you've got comfort complaints in specific rooms, we'll trace the duct runs to those areas and check for restrictions, leaks, or undersized branches. We'll explain what we find in plain terms — no jargon, no upselling — and give you a clear picture of what's failing and why. If a repair will solve the problem, we'll tell you. If the ductwork is so compromised that patching it is just delaying the inevitable, we'll tell you that too, along with what replacement would cost and what you'd gain from it.

We're licensed and insured in Illinois and Missouri, and we've been serving Southern Illinois long enough to know the common duct problems in this region: undersized returns in older homes, flex duct failures in humid crawlspaces, and rust issues in basements that flood every spring. We don't pressure you into same-day decisions, and we don't walk in with financing pitches before we've even looked at your system. You'll get a written estimate, a realistic timeline, and a crew that cleans up after the job — no metal scraps left in your yard, no drywall dust on your furniture. We're your neighbors, and we work like it.

Complete HVAC Services Across Southern Illinois

Ductwork problems rarely exist in isolation. If your ducts are leaking or undersized, your furnace or air conditioner is working harder than it should, which shortens its lifespan and drives up your energy costs. That's why we often recommend pairing duct repairs with a system evaluation — it's a chance to verify that your equipment is running efficiently once the delivery system is fixed. If you're replacing old ductwork, it's also the right time to evaluate whether your furnace or AC is still adequate for your home's load, because undersized equipment will struggle even with perfect ducts.

We offer full heating installation and replacement and air conditioning installation services, and we approach every job with the same sheet metal expertise that informs our ductwork. A furnace replacement isn't just about swapping the cabinet — it's about making sure the new unit connects properly to your existing ducts, that the plenum is sealed and insulated, and that airflow is balanced across every register. When you work with a company that understands both the equipment and the delivery system, you get a complete solution instead of piecemeal fixes that never quite add up.

Get Your Ductwork Fixed Right

If you're losing conditioned air to leaks, fighting comfort problems in specific rooms, or watching your utility bills climb without explanation, your ductwork is likely the culprit. We've been solving these problems across Southern Illinois for years, and we'll give you an honest assessment of what's failing and what it'll take to fix it — no high-pressure sales, no inflated quotes, just straightforward answers from people who do this work every day.

Call Smith Heating, Air & Sheet Metal or reach out through our contact page, and we'll schedule a time to take a look. You'll get a written estimate, a clear explanation of the work, and a crew that shows up when we say we will. Let's get your system delivering the comfort and efficiency it was designed for.