Quick Answer: Count ductwork, registers, and units from mechanical drawings in seconds. CyanBuild reads your HVAC drawings, counts every register, diffuser, air handler, condenser, and damper by symbol, and measures supply, return, and exhaust duct runs in linear feet. Each line item carries a confidence flag so your estimator knows what to verify.
HVAC takeoff is the process of measuring every quantity on a mechanical plan, the units your trade actually bills on. Done by hand it means counting symbols one by one and tracing duct runs with a scale wheel, which is slow and full of errors. AI reads the same drawings in seconds and reports the same quantities, with the math shown for every number.
What Trade Specific Takeoff Means
HVAC work sits in CSI Division 23, and it is the trade where takeoff has the most moving parts. A single mechanical set carries equipment, ductwork, piping, controls, and the schedules that tie them together. The estimator counts air handlers, RTUs, VAV boxes, diffusers, registers, dampers, and thermostats by symbol. They measure supply, return, and exhaust duct in linear feet, broken out by duct type and size, because a 24 by 12 galvanized run is a different unit cost than a 12 inch flex run. They also take off the hydronic piping, the refrigerant lines, and the condensate drains, each on its own line item.
Trade specific takeoff means the software knows that a square diffuser and a round diffuser are different devices with different costs, that a fire damper in a rated wall is not the same as a volume damper in a branch, and that the equipment schedule on sheet M201 controls the unit count and the model numbers on the plan. Without that trade knowledge you are left counting symbols on a PDF and typing duct lengths into a spreadsheet, which is the manual workflow takeoff software is supposed to replace.
What Counts on the Drawings
A mechanical set typically includes floor plans for supply, return, and exhaust, the equipment schedules, the duct sections, and the control diagrams. The quantities live across all of them. On the plans you count diffusers, registers, grilles, VAV boxes, dampers, and thermostats by symbol, and you trace the duct runs to scale, broken out by the size callouts on the duct. The equipment schedules give you the air handlers, RTUs, condensers, boilers, chillers, and pumps, with the model numbers that drive the unit price. The duct sections detail the fittings and the transitions, which is where most manual takeoffs lose counts.
Duct fittings are the part most estimators undercount by hand. A 200 foot run of 24 by 12 supply duct is not just 200 feet of straight duct. It includes the elbows at every direction change, the transitions at every size change, the takeoffs at every branch to a diffuser, the dampers at every zone, and the hangers and the sealant along the run. A takeoff tool that reports duct length but ignores the fittings and the accessories leaves you short on the order and short on the bid, because fittings are a large share of the sheet metal cost.
What Good Takeoff Software Does for This Trade
Good HVAC takeoff software reads the scaled PDF or DWG, recognizes the device symbols on the plan, and matches them to the equipment schedule so an air handler tagged AHU 1 on the plan pulls the AHU 1 row from the schedule, with the right model and capacity, instead of making you flip sheets. It traces supply, return, and exhaust duct separately, reports duct by the foot broken out by type and size, and applies the fitting counts based on the run geometry, the direction changes, the transitions, and the branch takeoffs.
The better tools also keep duct, hydronic pipe, refrigerant line, and condensate on separate line items, with the equipment count folded in from the schedules, so the takeoff reads the way the sheet metal contractor buys and installs the job. That structure is what lets the estimator hand the takeoff to a foreman without re explaining it, because the line items already match the way the field thinks about the work.
Must Have Features
- Device symbol recognition tied to the schedule. Count diffusers, registers, grilles, VAV boxes, dampers, and thermostats by matching plan symbols to the device and equipment schedules.
- Duct measured by type and size. Linear feet of galvanized, fiberglass, and flex duct, broken out by duct dimensions, with supply, return, and exhaust on separate line items.
- Fitting and accessory counts from the run geometry. Elbows, transitions, takeoffs, dampers, hangers, and sealant applied from the run layout, not counted by hand.
- Hydronic and refrigerant piping. Linear feet of chilled water, hot water, refrigerant, and condensate lines, broken out by type and size.
- Confidence flags on every line. High, Medium, or Low per item, so review time goes to the counts that need it.
- Sheet and location traceability. Every quantity links back to the sheet and grid coordinate it came from, for a defensible bid.
What to Watch Out For
The most common gap is a tool that counts devices and measures duct length but ignores the fittings, the transitions, and the accessories. A device count and a duct length is the easy part of an HVAC takeoff. The fittings, the dampers, the hangers, and the hydronic and refrigerant piping are where the hours and the dollars actually live, and a tool that stops at duct length leaves you building the rest of the order by hand.
Watch for tools that only read the floor plans and ignore the schedules. The equipment schedule is what turns a symbol count into a priced takeoff, because the model number drives the unit cost. If the tool cannot link the plan tag to the schedule row, you are still doing that step by hand. Also confirm the tool reads scanned PDFs, because a large share of HVAC bids start as flattened plan sets, and ask whether the confidence flagging tells you why an item is flagged, not just that it is.
How CyanBuild Fits
CyanBuild reads PDF, DWG, DXF, and image files, including scanned sheets, and counts every register, diffuser, air handler, condenser, and damper by symbol, matched to the equipment schedule. It measures supply, return, and exhaust duct in linear feet by type and size, applies the fitting and accessory counts from the run geometry, and takes off the hydronic and refrigerant piping on separate line items. Every line item carries a confidence flag tied to the sheet and grid location, and the export is a line item takeoff ready for pricing, with the math shown for every quantity.
Putting It Together
HVAC takeoff is the busiest takeoff in the building, because it carries equipment, ductwork, piping, and controls on the same set. The device count is the easy part. The value is in the fitting counts, the schedule cross references, and the separate line items for duct, hydronic, and refrigerant that match the way the job is bought and installed. Pick software that does the device count, the duct length, and the fitting math in one pass, flags the items it is less sure about, and shows the math behind every number. That is what turns a takeoff from a manual count into a defensible bid, and it is what lets your estimator spend the saved hours on coordination and value engineering instead of clicking symbols on a PDF.