HVAC contractor BOQ: what to include and compare — selection basis, interfaces, TAB and exclusions

An HVAC BOQ that stops at "chiller, 200 TR" cannot be priced, compared or held to. Equipment is only part of a mechanical contract: the pipe, duct, insulation, controls, testing and balancing decide whether the equipment ever delivers its rating, and the interfaces with the civil and electrical packages decide who pays for everything in between. If those are not lines in the BOQ, they are not in the price — and they come back as variations.

The structure below follows the order a mechanical BOQ should be written in: the selection basis, the lines, the interfaces, the testing and documentation, and the work excluded from the HVAC contract with the party who does it.

1. The equipment selection basis — the page before the lines

Before any quantity, the BOQ needs the basis the equipment was selected on: the indoor conditions to hold (temperature, humidity, and filtration or cleanliness class where it matters), the outdoor design conditions and their source, occupancy and the fresh-air basis, process heat loads and when they run, operating hours, diversity and redundancy. A BOQ without a stated basis is priced against each bidder's private assumptions, and the assumptions will differ.

Name the standards the design follows, with their editions. Part 8, Section 3 of the National Building Code of India 2016 (BIS) covers air conditioning, heating and mechanical ventilation. Whether the Energy Conservation and Sustainable Building Code (ECSBC 2024, from the Bureau of Energy Efficiency) applies depends on your state's notification and on the project's connected load and occupancy — check both for your project before writing efficiency requirements into the BOQ.

Keep the units apart. Tonnes of refrigeration and kW of cooling are thermal capacity (1 TR is about 3.517 kW thermal); the kW a machine draws is electrical input. An efficiency figure means nothing unless the BOQ says which it divides by which, and at what conditions. The tonnage and chiller capacity calculators give a first check that the plant in a BOQ matches the load.

2. Plant, air-side and water-side lines

• Plant — chillers, cooling towers, VRF units, AHUs, FCUs, pumps, fans, dehumidifiers and heat exchangers: each a line with the selection data above, two or three named acceptable makes, and the quantity.
• Ductwork — measured in square metres of sheet by thickness from the coordinated drawings, not estimated from floor area, with the construction standard named (IS 655 from BIS, or a SMACNA class) and its edition.
• Terminals and dampers — diffusers, grilles, VAV or CAV boxes and volume-control dampers, plus fire and smoke dampers at every compartment crossing shown on the fire drawings, each counted.
• Piping — chilled-water, condenser-water and drain lines by size, material and pressure class, measured from the drawings; valves, strainers and balancing valves counted by size; expansion tanks, air separators, water treatment and instrumentation listed.

3. Duct insulation, controls and power interfaces

Insulation. Duct and pipe insulation by material, thickness, density and vapour barrier, separately for concealed and exposed runs, with cladding where it is outdoors. The thickness decides whether the ceiling drips; a BOQ that leaves it to the bidder will receive the thinnest one that passes inspection.

Controls. Sensors, actuators and controllers by count; the sequence of operation; the BMS points list; and, explicitly, who supplies the BMS, who programs it and who integrates the HVAC controls into it. BMS lock-in usually begins in a BOQ that left this line blank.

Power. Where the HVAC contractor's electrical scope starts and stops — starter and VFD panels, cabling from each isolator to its machine, control wiring, equipment earthing — and the supply the electrical package must bring to each item, stated in kW or kVA at a named termination point. This interface is a frequent source of site disputes, because each contractor reads the other's BOQ as covering it.

4. TAB, commissioning and documentation

Testing, adjusting and balancing gets its own section, with priced lines:

• Duct leakage testing, section by section, before the ceilings close — why leakage and balancing decide performance
• Hydrostatic testing and flushing of pipework, with the test pressure and duration taken from the specified standard
• Air balancing at every terminal and water balancing at every coil, recorded against design values
• Point-to-point checks of every control point
• Start-up by the equipment manufacturer where its warranty requires it
• The integrated test with the fire alarm — damper closure, AHU shutdown, pressurisation and smoke exhaust

Then the documents, also priced: the balancing report with measured against design values, commissioning reports, as-built drawings, O&M manuals, operator training, and any rating-scheme documentation the project is seeking. What commissioning involves is worth reading before the BOQ is issued.

5. Excluded civil and electrical works — named, with an owner

Every HVAC BOQ excludes something. The trouble is exclusions that are implied rather than listed, because each one is then priced twice or not at all. List the excluded works and who does each:

Reading a bidder's BOQ against this structure

Go section by section. A quotation with no TAB section, an insulation line without a thickness, or plant without named makes and rating conditions is not cheaper; it is less complete. Put the bids on common quantities and add the missing sections at the rates other bidders quoted — how to compare MEP quotations sets out the method, and the MEP quotation comparison calculator does the arithmetic — and only then compare totals. The tender BOQ checklist covers the rules that keep a BOQ enforceable after award, and more planning guides are on the Insights page.

The HVAC service page and its buyer's guide list what to have ready before asking for a mechanical proposal. To have a BOQ or a set of bids checked, share the layout, the operating schedule and any existing HVAC data.

Sources and how to verify

• National Building Code of India 2016 (SP 7:2016) — Bureau of Indian Standards. Part 8 (Building Services), Section 3: air conditioning, heating and mechanical ventilation.
• Energy Conservation and Sustainable Building Code (ECSBC) 2024 — Bureau of Energy Efficiency. Applicability depends on state notification and on the project's connected load and occupancy.
• Know Your Standards — Bureau of Indian Standards: the current edition and amendments of IS 655 or any other standard your specification names.

Confirm locally: whether your state has notified ECSBC 2024 and whether your project falls within it, what your fire authority requires of dampers, pressurisation and smoke exhaust in your building, and the editions of every standard the specification cites.