The homes that will make a panicked call in July are identifiable in February. That single fact organises everything about an HVAC floor’s data: what the file is built from, when it is dialed, and why a generic homeowner list — dialed whenever the seats are free — books tune-ups at the wrong time of year for the wrong houses.
This is the data page for an HVAC floor. Three lists, each with its own filter and its own month, and the columns each row has to carry so the setter can open with the permit rather than the pain. The conversation itself — the pre-season call, the after-heatwave call, the furnace call — is in the HVAC cold call script, and every figure below is from HVAC replacement statistics unless another page is named.
Disclosure: Scout Data is our product. The permit database the age and season figures come from is ours, and the file described here is what we build for HVAC floors. The lists are buildable from any source that carries a dated mechanical permit.
System age comes from the permit, not the house
Manufacturers say a furnace lasts 15 to 20 years and an air conditioner 10 to 15. Permits say what homeowners actually did. Where the same home appears twice in the record for the same kind of equipment, the gap between the two jobs is the closest thing the data has to a service life: a median of 13 years for a furnace or boiler and 12 for air conditioning, with the 75th percentile at 19 and 17. Both medians are floors — a jurisdiction that began publishing in 2005 cannot show a 25-year interval — so the true centre sits above them and the manufacturer range is compatible with what the permits show.
The trap is the house. The median home is 39 years old when an HVAC permit is pulled on it, and the distribution has no peak: an old house has already cycled through several systems and is no more likely to be due this year than any other old house. House age alone will not find a failing furnace. The one band where it works is homes 15 to 24 years old — 612,634 permits — because that is where the original system is reaching the end of its first life and house age and equipment age still coincide. Everywhere else, the age list is “last cooling or heating permit past the local threshold,” and the threshold is set from the two medians above, not from a national rule of thumb.
The season decides the month, and the month decides the list
Residential HVAC permits by month across 2021–2025, split by what the permit describes:
| Month | Cooling permits | Heating permits |
|---|---|---|
| February | 110,433 | 106,814 |
| April | 136,974 | 99,042 |
| June | 180,388 | 103,091 |
| July | 182,383 | 103,943 |
| September | 143,826 | 96,198 |
| October | 142,160 | 117,100 |
| December | 116,624 | 117,345 |
Cooling swings 65% from its February floor to its July peak; heating swings 22%, and its peak is a broad October-to-January plateau rather than a spike. The two curves describe two different purchases. Air conditioning is replaced when it dies in a heatwave — a distressed buy at the worst moment for price. Heating is replaced on a schedule, with its peak landing before the cold, which means a meaningful share of furnace jobs are planned. For a call center that is the whole arbitrage: the aging-cooling list is dialed in February through May, when the homeowner can still plan, and the furnace list in August through October, when the schedule is being made. The month-by-month version of the year is HVAC replacement season planning.
Move-ins: the list with no age filter
The third list is the one where nothing about the system matters. A new owner has no contractor yet, is making a dozen decisions in a few months that they will not revisit for years, and will take a call that acknowledges the move. Of the 3,665,576 single-family homes that recorded a sale in the trailing year, 2,544,602 — 69.4% — are owner-occupied; the other 30% are investor purchases where the arriving household is a tenant. Filter for owner-occupied and for an arms-length sale, because a deed also gets recorded when a parent adds a child to title or a house moves into a trust, and nobody moved in.
Speed is the product. The advantage decays as the household acquires incumbents, so list latency is a bigger lever than list size — a programme pulling new movers monthly is dialing a population whose average record is already weeks stale. And the supply is thin: at a national turnover of 4.3% a year, a territory of 5,000 homes yields around 150 owner-occupied movers annually, which makes this a supplement to the two aging lists rather than a floor’s primary file. How to find new movers covers the transfer-type trap and the latency chain.
Fuel decides the sentence
Of residential replacement permits filed 2023–25, the share naming a heat pump, mini-split or ductless system runs from 35.6% in Maryland to 1.0% in Michigan — a 35-times spread that has nothing to do with climate and everything to do with what the house already burns. The Southeast and mid-Atlantic heat with electricity, so a heat pump is the like-for-like replacement; the Midwest heats with gas, where a heat pump means abandoning a working gas line. For the floor that means the file has to carry heating fuel, and the heat-pump sentence in the furnace call lands only where the fuel says it will. A list without the fuel column makes the setter guess, and a wrong guess ends the call.
Three lists for three calls
| List | Filter | Dialed | The call it feeds |
|---|---|---|---|
| Aging cooling | Last cooling permit past the local threshold; owner-occupied; no mechanical permit in the last five years | February to May | The pre-season call |
| After the event | The same homes, filtered to the streets a heatwave or cold snap actually hit | The week after | The after-the-heatwave call |
| Aging heating | Last heating permit past the local threshold; heating fuel on the row; owner-occupied | August to October | The furnace call |
| Move-ins | Arms-length sale in the last 90 days; owner-occupied | Weekly, as recorded | Any of the three, opened on the move |
Which homes get which call is decided by the file before the setter dials, and the HVAC cold call script is written on that assumption — its three calls are the three rows above with the move-in opener layered on any of them.
What the HVAC row carries
- Last mechanical permit date and equipment class. Cooling and heating separately — pooled together the median interval reads 11 years, which is a furnace from 2014 averaged with an air conditioner from 2020 and describes neither.
- Heating fuel. Gas, electric, oil, propane. The heat-pump line depends on it.
- Build year, for the 15-to-24 band where it still means something.
- Sale date and owner-occupied, for the move-in list and as a gate on all three.
- The dialer columns: a phone matched by name to the owner on title, line type, timezone from the ZIP, and the registry scrub date — the spec in homeowner phone lists for call centers.
Suppress, then scrub
Off every list before load: homes with any mechanical permit in the last five years, because a new system is not a replacement conversation; renters, logged as their own outcome when one slips through; your customers and service history, which is the one suppression file no vendor can sell you; and anyone who asked you to stop. Then the registry scrub, run after the phones exist and dated on the file. The routine, including the state rules that only exist after a declared disaster, is DNC scrubbing for roofing and HVAC. Judge each list on held technician visits per right-party conversation, by season, with the three stamped separately at import — a February list and an August list are not competing for the same homeowner.
Frequently asked questions
What are the best leads for an HVAC call center?
Homes whose system is old enough to be due, dialed before the season that will kill it. The permit record gives the age: the median gap between consecutive cooling permits on the same home is 12 years and between furnace permits 13, both floors. The calendar gives the timing: cooling permits swing 65% from a February floor to a July peak. And move-ins add a third list with no age filter at all — a new owner has no contractor yet.
How do I find homes with old HVAC systems?
From the last mechanical permit on the home and what it installed, not from the age of the house. The median home is 39 years old when its HVAC gets replaced and has already cycled through several systems, so build year says nothing about the current unit. The one exception is homes 15 to 24 years old, where the original system is reaching the end of its first life and house age and equipment age still coincide.
When should an HVAC call center dial its list?
Before the peak, not during it. The homes that will make a panicked July call are identifiable in February, and a floor that dials the aging-cooling list in spring is booking planned replacements while the competition waits for the heatwave. Heating is flatter — a 22% swing with a broad October-to-January plateau — and its list is dialed in late summer for the same reason.
Do new movers make good HVAC leads?
As a supplement, yes. Of the single-family homes that recorded a sale in the trailing year, 69.4% are owner-occupied, and each of those households is choosing contractors it will not revisit for years. The window closes as they acquire incumbents, so list latency matters more than list size — a monthly pull is already weeks stale on arrival.