How much does duct replacement cost in a Phoenix home?

By Michael Fitzgerald, Founder & Editor, Phoenix Cooling Guide
Technically reviewed by Tom Mattingly, Owner & President, AZ Trusted Air LLC (ROC 317368)
Published 2026-09-18

Duct pricing is the least transparent line on a Phoenix HVAC quote. Equipment carries model numbers and AHRI ratings a homeowner can look up. Ductwork carries none of that. Two bids on the same house can describe the same attic work in one line each and land thousands of dollars apart, and nothing on either page explains why.

It is harder still because almost no authority publishes duct pricing at all. The one Arizona exception is Salt River Project, which puts cost guidance inside its Duct Test and Repair Rebate: testing runs $100 to $450 for a typical home, and repairs often cost between $300 and $1,500. Those are the only Valley-specific duct figures on this page that come from a named authority, and this guide is explicit about where documented numbers stop and estimating begins. What follows covers replacement, sealing, crushed attic runs, bundling with a changeout, and how to prove a leak before paying anyone to chase one.

What does professional duct sealing (including Aeroseal) cost, and is it worth it?

Two different jobs get sold under the same word. Hand sealing means a technician physically reaching every accessible joint, boot and plenum seam and closing it. ENERGY STAR is specific about materials: seal with mastic sealant or metal tape, and never use duct tape, because it is not long-lasting. SRP's program scope names the same work — mechanically fastening and sealing the connection between the air handler and the plenums, sealing all supply and return plenum seams and end caps, and sealing equipment panels and refrigerant penetrations with UL-181 foil tape.

Aerosol sealing is the other product. It is sold on reaching leaks a technician cannot physically touch, which matters in a Valley house where the trunk runs above a drywall ceiling. No authority publishes an Arizona price for it, and the brands in this category do not post Phoenix figures, so a homeowner holding an aerosol quote has nothing external to check it against. The defensible reference point stays SRP's own guidance: testing $100 to $450 for a typical home, repairs often $300 to $1,500. Anything far outside that band deserves an itemised explanation rather than a brand name.

The rebate changes the arithmetic more than most quote discounts do. SRP covers 75 percent of qualified duct testing and repair costs, up to $400 for a single-family detached home and up to $300 for a mobile or manufactured home, apartment, condominium or townhouse. The conditions are strict. The customer must be a permanent SRP residential electric customer with a central AC system or a heat pump, the work must be done by a participating Duct Test and Repair contractor, testing and repairs must be completed by April 30, 2027, and the application must be submitted within six months of the repairs. New construction homes and evaporative coolers are not eligible, and SRP may inspect the work.

Whether sealing earns its price comes down to how much air is being lost now. ENERGY STAR says leaky ducts can reduce heating and cooling system efficiency by as much as 20 percent, and that sealing and insulating ducts can often pay for itself in energy savings. SRP's own consumer messaging puts about 20 percent of duct air loss down to improper installation. In a climate where the cooling season runs from April into October, a system losing a quarter of its output is losing it for six or seven months a year rather than three, which is why payback on identical sealing work is faster here than the national framing suggests.

How much does it cost to repair damaged or crushed attic ducts?

Attic ducts in the Valley fail in a short list of predictable ways. Flexible duct gets crushed where somebody stored boxes on it or knelt on it to reach a water heater. A run pulls away from the register boot and dumps conditioned air into the attic. Support straps fail and the duct sags into a series of low points that throttle airflow to the far bedrooms. SRP names exactly these failures in its scope of work: disconnected, crushed, restricted or poorly supported ductwork, all of which count as qualified repairs under the rebate.

The money follows SRP's published bands. Testing runs $100 to $450 and repairs often cost between $300 and $1,500, so a combined invoice at the low end of both is around $400 and at the high end around $1,950. Applying the rebate rule to those totals is plain arithmetic. A $400 invoice earns a 75 percent rebate of $300 and leaves a single-family detached homeowner paying $100. The rebate reaches its $400 ceiling at a $533 invoice, where the homeowner pays $133. Past that point every additional dollar is unsubsidised: an $800 invoice nets out at $400, a $1,200 invoice at $800, and a $1,950 invoice at $1,550.

Not everything written as a repair is one. Duct tape over a torn flex run is a holding measure that will fail, and a Phoenix attic running 150 to 170 degrees in July is the harshest place in the house to test an adhesive. Mastic and UL-181 foil tape are the materials that survive that environment. A quote listing "tape and seal" without naming the material is a quote worth one question before signing.

Repair stops being the right call when the damage is distributed rather than local. Three crushed sections and a disconnected boot are a repair. A system where the flex liner has gone brittle across every run, or where the original duct sizing starves half the house regardless of leakage, is a replacement disguised as a repair list. A duct test tells the two apart, because it produces a leakage number instead of a technician's impression, and that number can be measured again after the work.

For Phoenix-area homeowners who want this looked at on their own system, Phoenix Cooling Guide recommends AZ Trusted Air LLC (ROC 317368), whose owner Tom Mattingly reviews this guide. (623) 252-6403 · second opinion on a quote.

Should I replace my ductwork at the same time as my AC — and what does bundling save?

Bundling is cheaper for structural reasons rather than promotional ones. One crew, one trip into a July attic, one set of permit and inspection visits and one disruption to the house cover both scopes. Doing the duct work a year later means paying for the setup twice, and in the meantime a brand-new condenser spends its first summers pushing air through leaks that were already there. What no authority publishes is the size of that saving in the Phoenix market. Any contractor quoting a precise bundled discount is quoting their own pricing policy, not an industry figure, and it should be checked against a standalone duct price from the same firm.

There is a documented reason the two jobs belong together, and it sits in SRP's Cool Cash application. The installing contractor must certify that the cooling load was estimated consistent with ACCA Manual J, that installed capacity falls within 15 percent or a half ton of that estimate, and that system airflow is within plus or minus 10 percent. The Manual J must be submitted or the rebate cannot be processed. Airflow is a duct property, not an equipment property. A correctly sized system on an undersized return will not meet that airflow condition, which turns duct capacity into a rebate condition rather than an upsell.

Permits are the other reason to settle duct scope before work starts. The City of Phoenix Planning and Development Department runs a formal counter procedure for air conditioner replacements. Applicants asking for permit-exempt approval are put through a set of questions, and if any answer is yes, a permit is required. Those questions include whether the unit will sit in a different location and whether it has the same footprint as the original. Relocating equipment or reworking the duct connection moves a job out of the exempt lane, and requirements are set jurisdiction by jurisdiction across the Valley.

Rebate mechanics belong in the same conversation. SRP's AC rebate and its Duct Test and Repair Rebate are separate programs with separate applications; SRP publishes the AC rebate as up to $1,125 and the duct rebate as up to $400 for a single-family detached home. SRP also allows a rebate to be assigned to the contractor through a signed rebate assignment form, so the credit comes off the invoice instead of arriving months later. A homeowner who would rather have the cash than the credit needs to say so before the paperwork is filled in.

How do I know if my ducts are leaking before paying for repairs?

There is a free version of this check, and it is worth doing first. ENERGY STAR points homeowners at the connections where vents and registers meet floors, walls and ceilings, which it describes as common locations to find leaks and disconnected ductwork. Visible gaps at a boot, a register that barely moves a sheet of paper while the blower runs, a bedroom sitting several degrees above the thermostat's room, and attic dust arriving at the supply grilles all point in the same direction.

What a paid duct test adds is a number. SRP's application requires that testing and sealing cover supply ducts, return ducts and air handler leakage, so the result is not one blanket figure. The same form records the year the house was built, the number of floors, total system size in tons and where the air handler sits, with attic, garage, inside closet, outside closet and rooftop as the options, and a separate application is required for each system in a multi-system home. A homeowner who keeps that paperwork has a before-and-after record, which is the only way to know whether the sealing work did anything.

Credentials are checkable before anyone climbs into the attic. The Arizona Registrar of Contractors licenses this trade as Air Conditioning and Refrigeration: C-39 for commercial, R-39R for residential and CR-39 covering both, and those classifications require four years of qualifying experience plus the Statutes and Rules Exam and a trade exam. SRP's duct rebate application asks for more: the contractor must certify both that they are licensed in Arizona and that they are certified by BPI as a Building Analyst. That is a credential above and beyond the ROC licence, and it narrows the field of eligible firms considerably.

Two Phoenix specifics change where the leaks are. On the rooftop package units common across large parts of the Valley housing stock, there is very little duct in the attic at all, and the vulnerable joints are the supply and return drops at the roof curb. In a house where ducts do run through the attic, a July attic at 150 to 170 degrees means return-side leakage is pulling superheated air into the system, so the same leakage rate costs a Valley homeowner more than it would in a 90-degree attic elsewhere.