Do I Need To Have The Ductwork In My Building Inspected?
If the building predates 1990 and the ducts have never been tested, yes - and test rather than inspect. A visual look in the attic finds crushed flex and disconnected boots; only a measured static pressure and leakage test tells you whether the system can move the air it is rated for.
Inspected, or tested?
Someone looks
Finds the obvious: a disconnected boot, a crushed flex run, missing or fallen insulation, rodent damage, a return plenum open to the attic. Worth doing, and it will not tell you whether the system is choking.
Someone measures
Total external static pressure in inches of water column, compared to the equipment’s rated maximum, plus a leakage measurement. Produces numbers you can act on and compare year to year. This is what Duke Energy’s duct rebate pays toward.
Ask for the test. An inspection is what you get for free with a sales visit; a test is what tells you whether the $9,000 you are about to spend on equipment will actually perform.
When a duct test earns its cost in Casselberry
When it is genuinely worth doing, in rough priority order for this city:
- Before any changeout on a pre-1990 house. That is 77% of Casselberry — 19.9% built before 1970 plus 57.1% built 1970–89. Sizing the new equipment without knowing the duct restriction is guessing.
- When one room never keeps up. A single warm bedroom is a distribution problem far more often than a capacity problem, and replacing the equipment will not fix it.
- When the house is humid but cold. Return leakage from a hot attic is a classic cause and it is invisible without a test.
- After any roof or attic work. Roofers and insulation crews step on flex duct. It is not malice, it is physics.
- When the electric bill has drifted up without the system failing. Why the bill went up.
What it costs and what Duke pays
Cost and who pays: a diagnostic visit in this market is a researched $75–$150. Duke Energy pays 50% of the cost of the duct test plus up to $200 toward repairs, single-family only, after the free Home Energy Check. If repairs or replacement are needed, the Florida guide puts that at $1,500–$5,000 as part of a changeout.
One thing a duct test is not: a building inspection. A permitted changeout in Casselberry is inspected by the city or the county, and that inspection is about code compliance, not about whether your ducts perform. What the permit inspection covers.
Book the free Duke Energy Home Energy Check before you replace anything.
Duke Energy requires a free Home Energy Check completed within the previous 24 months to qualify for any Home Energy Improvement rebate. Replace the system first and apply afterwards and the application is denied — there is no retroactive path back.
It is a no-cost visit and it is the single most common way a Casselberry homeowner loses a four-figure rebate. If you are within a year of replacing, book it now, before you call anyone for a quote. Duke’s rebate line is 800.254.8535.
Cold in one room, hot in another?
That is the symptom a duct test is for. Replacing the equipment first is the expensive way to find out.
Phone: (689) 308-3675 · Monday-Friday, 8:00 AM - 5:00 PM
Where the facts on this page come from
Every figure above is either a primary-source document or a named third-party cost guide. All of it was checked in September 2026. Fee schedules, rebate amounts and market prices change without notice — if you are about to spend money on one of these numbers, open the source and check it.
- Duke Energy, Home Energy Improvement HVAC replacement
- Duke Energy, Home Energy Improvement prerequisites (Florida)
- This Old House, air conditioner repair cost guide (updated 16 March 2026)
- I’m Moving to Florida, Florida AC replacement cost guide (reader-supported, methodology not disclosed)
- Seminole County Property Appraiser