How Do HVAC Contractors Send Estimates? Timing, Format, Follow-Up

Short answer: Most HVAC contractors send estimates the same day they measure, often before leaving the driveway — a PDF built on a tablet, emailed and texted, showing two or three system options priced by tonnage and SEER2. Capacity comes from a Manual J load calculation, not from the home’s square footage, where 1 ton equals 12,000 BTU/h. Replacement quotes usually stay valid 15 to 30 days. Repairs get quoted flat rate and signed on the work order before a wrench turns.

Two completely different sales rhythms live inside this trade. A system replacement is a sit-down presentation with options, financing, and a decision that may take a week. A no-cool call in July is a price given at the condenser in four minutes. Sending both the same way loses one of them. The document that follows the win is a different animal again — see what to include on an invoice.

How soon after the site visit does the estimate go out?

For replacement work, same visit or same day. The homeowner is at their most motivated while the tech is still in the mechanical closet, and a quote that arrives Thursday for a Tuesday visit has already lost to whoever handed over a number on Tuesday.

The practical version: measure, photograph, and run the load on site; build the options in the truck; send the PDF before the next call. If the job needs something you cannot price at the curb — a supplier confirmation on a matched system, a permit fee lookup, a load calc you want to redo properly — say when it will arrive and hit that time. “Tomorrow by noon” that lands at noon sells better than a same-day guess with a hole in it.

Emergency service is the opposite: no document at all until the diagnosis is done, then a flat-rate number given verbally and immediately written on the work order.

What has to be measured before a price exists?

Capacity is the number everything else hangs from, and the shortcut everyone reaches for — square footage — is the single biggest source of bad HVAC quotes.

Sizing comes from a load calculation: orientation, insulation, glazing, infiltration, duct location and leakage, ceiling height, occupancy. The result is BTU per hour, and 12,000 BTU/h is one ton of cooling. Guess low and the system runs continuously and still cannot hold the space on a design day. Guess high and it satisfies the thermostat in short bursts, never runs long enough to pull moisture out of the air, and the customer calls a cold, clammy house a defect — which, functionally, it is.

Input	Why it moves the price
Load calculation result, in BTU/h and tons	sets the equipment, and everything sized off it
Existing duct system — size, layout, condition, leakage	undersized returns cap what any new unit can deliver
Line set length and routing	reuse, flush, or replace changes the labor and the material
Electrical service, breaker, and disconnect	a new circuit or panel space is a separate scope
Refrigerant type of the existing system	affects what can be matched, reused, or recovered
Access — attic, crawl, closet, rooftop	drives labor hours more than the equipment does
Permit and inspection requirements	jurisdiction, fee schedule, and inspection trips

Regional efficiency minimums apply on top of all that: the federal standards are enforced by climate region, so the floor for a split system differs between the northern and southern regions, and the Department of Energy’s regional standards enforcement page is where the enforcement side lives. Quoting below your region’s minimum is not a discount; it is a compliance problem you own.

How many options should the homeowner see?

Two or three. One is a take-it-or-leave-it. Four or more turns a decision into a research project and stalls it.

Tier	What actually changes	What the homeowner feels
Baseline	region-minimum SEER2, single-stage, matched indoor coil, existing ducts	lowest price, same comfort behavior as before
Mid	higher SEER2, two-stage or communicating controls, duct corrections included	longer run times, quieter, better humidity control
High	variable capacity, higher SEER2, zoning or air quality accessories	most even temperatures, highest first cost

Price each tier as a complete installed job, not as an equipment price with the labor hidden underneath. And make the tiers differ in something the customer can feel — staging, sound, humidity control — rather than in a number they have no way to interpret. A homeowner cannot tell you what SEER2 they want. They can tell you the upstairs bedroom is eight degrees hotter than the living room.

What does each line on an HVAC estimate have to name?

Anything a competing quote could quietly leave out.

• Outdoor unit and indoor unit as a matched pair, by model number, with the rated tonnage and the SEER2 of that combination, since efficiency ratings belong to the matched system rather than to the condenser alone.
• Line set: length in feet, reuse with flush versus new, and the fittings.
• Ductwork: linear feet modified or replaced, or supply and return counts affected, plus sealing.
• Air handler or furnace platform, pad, hurricane straps, condensate drain and safety switch.
• Thermostat, by model, and whether it is compatible with the staging you sold.
• Electrical: disconnect, whip, breaker, and any new circuit.
• Permit and inspection, at cost, listed by name, with who pulls it.
• Refrigerant charge and line set evacuation, stated as part of commissioning.
• Removal and disposal of the old equipment, including recovery of the existing refrigerant, which is regulated work under EPA Section 608.
• Startup and commissioning: static pressure, subcooling or superheat, airflow, and the report the customer receives.
• Exclusions: duct replacement beyond a stated footage, electrical panel work, drywall, asbestos-containing duct insulation, and anything behind a wall nobody has opened.

How long is an HVAC estimate valid?

Shorter than most trades, and for reasons you can point to. Equipment pricing changes on the manufacturer’s schedule, not yours; refrigerant and regulatory transitions have moved product availability more than once — the shift away from higher-GWP refrigerants in new residential systems reshaped the catalog on a fixed date, not gradually. A number you quoted in April may not be purchasable in July.

Fifteen to thirty days is a common window for replacement quotes. Write the reason next to it in one sentence: pricing is held for that window based on current equipment cost and availability. That sentence prevents the awkward call where a customer accepts a five-month-old proposal and expects the old total.

Also state what the price assumes. The three assumptions worth naming every time: the existing duct system is reused as-is, the electrical service has capacity for the new equipment, and the line set is reusable after a flush. Each of those is a change order waiting to happen, and each is cheaper to disclose than to explain.

How is a service-call quote different from a replacement quote?

Completely different transaction. On service you sell a diagnosis first, then a repair.

State the diagnostic fee on the phone before the truck rolls, and say plainly whether it credits toward the repair. On site, diagnose, then quote the repair flat rate — a per-task price out of your own book, not an hourly guess — and get a signature on the work order before opening anything. Photograph the failed part, because a capacitor or a contactor in a box means nothing to a customer three weeks later.

When the repair approaches a meaningful share of a replacement, present both numbers on the same page: the repair, and the baseline replacement tier. Let the homeowner choose with the two figures side by side rather than calling them back a week later after the compressor is out.

When do you follow up, and how does the yes get recorded?

Follow up on a schedule you decide in advance, because replacement decisions run on the homeowner’s calendar and their spouse’s opinion.

When	What you send
Same day	the PDF, plus one text confirming it arrived
Day 2 or 3	a call answering the question they did not ask in front of you
Day 7 to 10	a note that the price window is running, with financing or a scheduling slot
At expiry	one message stating the quote has expired and offering a refresh

Then stop. Three touches and an expiry note is a follow-up sequence; eleven is a reason not to answer the phone.

Record the acceptance in a form that survives a dispute: a signature on the proposal, an e-signature, or a text that names the option and the total. A screenshot of “let’s do the mid one, $X” with a date is worth more than a remembered phone call. Take a deposit that matches actual equipment commitment, note the scheduled install date, and confirm both in writing the same day. Some states cap the deposit a home improvement contractor may collect up front, so check your rule before you set a policy.

How do you build your own number instead of copying one?

Reverse the estimate. Start from equipment and material at your real supplier cost, including the line set, pad, thermostat, whip, drain assembly, and the permit fee. Add labor as crew hours from your own completed installs, priced at your loaded hourly cost — wages, payroll burden, insurance, truck, EPA-certified tech time, and the shop hours nobody bills. Add overhead as a share of every job. Then apply profit as a margin, not as a markup on equipment.

That last distinction quietly eats HVAC shops, because equipment cost is a large share of the ticket. A 30 percent markup on $6,000 of equipment and material bills at $7,800 and keeps $1,800 — a 23 percent margin, not 30. To keep 30 percent you divide by 0.70 and bill $8,571. On a trade where a single system can carry five figures, that gap is the difference between a profitable year and a busy one.

Treat published market ranges as a sanity check only. Installed system prices swing enormously with tonnage, staging, duct scope, attic versus closet access, regional labor rates, permit fees, and the month of the year. Your own cost is the only figure that decides whether the job is worth doing.

What happens to the paperwork once the job is sold?

The estimate is the beginning of a file: the load calculation, the model and serial numbers of both units, the permit number, the commissioning readings, the startup photos, the equipment invoice from the supply house, and the registration confirmation for the manufacturer warranty. That file settles a warranty claim years later and supports the deduction at tax time.

Estimating itself is not what Keel does — that feature is still being built. What it handles is the hour after the yes and everything that follows it. The invoice for the deposit and the invoice on commissioning day each go out from the phone in about a minute, with your numbering, logo, brand color, and a payment link the customer scans as a QR code at the thermostat. Supply house receipts for the condenser, the coil, and 40 ft of line set are photographed at the counter and read on the device by Apple Intelligence: no account, no bank connection, no cloud, no login, and an App Store privacy label that reads Data Not Collected. Miles from the shop to the supply house to five service calls log as you drive, which matters more in this trade than most — see how to track mileage for taxes. Freeboard shows cash minus tax reserve, committed invoices, and buffer, and the year exports as a single file. Free includes unlimited invoices, receipts, and mileage; Keel Pro is a one-time $249.99 Lifetime purchase, not a subscription.

Quotes that turn into installs still turn into receivables, and the sequence for the ones that age is in how to get clients to pay.

Frequently asked questions

How long should an HVAC estimate take to arrive?

Same visit or same day for a replacement, because the homeowner decides while the visit is fresh and often has other companies coming. If a supplier confirmation or a load calculation redo delays it, name a specific time and meet it. Diagnostic and repair quotes are given on site immediately after the diagnosis and signed on the work order before any part is opened.

Do HVAC contractors size systems by square footage?

They should not. Sizing comes from a load calculation covering insulation, windows, orientation, infiltration, duct losses, and occupancy, expressed in BTU per hour, where 12,000 BTU/h equals one ton. Square footage rules of thumb produce oversized systems that short cycle and leave the house cold and humid, or undersized systems that never catch up on a design day.

How many options should be on an HVAC replacement quote?

Two or three, each priced as a complete installed job. Tiers should differ in something the customer can experience — single-stage versus two-stage or variable capacity, sound, humidity control, zoning — with the SEER2 shown for the matched pair rather than for the outdoor unit alone. More than three options stalls the decision instead of clarifying it.

How long is an HVAC quote good for?

Fifteen to thirty days is typical, and shorter windows are defensible in this trade because equipment pricing and availability move on the manufacturer’s schedule. Put the reason in one sentence next to the expiry date, and list the assumptions the price depends on: reusable ducts, adequate electrical capacity, and a line set that survives a flush.

How do HVAC contractors record that a customer accepted the estimate?

With a signed or e-signed proposal that names the option and the total, or a dated text message that does the same. A deposit sized to actual equipment commitment, plus a confirmed install date sent in writing the same day, closes the loop. Verbal approval over the phone is the version that gets remembered differently once the crane arrives.

Should a repair quote and a replacement quote go out together?

Yes, when the repair cost is a meaningful share of a new system. Present the flat-rate repair and the baseline replacement tier side by side, with the age of the equipment and the refrigerant it uses stated. The homeowner is choosing between spending money on a failing system and starting a new one, and that decision is easier with both numbers visible at once.

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This article is general information, not professional or tax advice.