Chiller Cost per TR: Plant Cost Drivers, Efficiency Class and Lifecycle

There is no honest chiller price per TR until the scope is fixed. The figure moves with chiller type, efficiency class, whether pumps, cooling towers, piping, electrical work and controls are included, and the site. Compare quotes per TR only when they cover the same plant boundary, and rank them on lifecycle energy and service, not purchase price. We quote no per-TR price here.

Why a per-TR number misleads

When someone says "chillers cost so much per TR", ask what that covers. A chiller-only price and a complete plant price can differ widely, and neither is wrong. The table lists what may or may not be in the number.

What actually moves the number

• Air-cooled or water-cooled. Air-cooled units cost less to install and need no tower or condenser water, but usually use more energy per TR. Water-cooled plant adds the tower, pumps and water treatment, and usually runs more efficiently.
• Compressor type and speed control. Screw, scroll and centrifugal machines suit different capacity ranges, and variable-speed drives improve part-load efficiency at a higher purchase price.
• Efficiency class. A higher-rated machine costs more up front and less to run. The code section below sets a minimum.
• Redundancy. An N+1 arrangement adds a whole machine. Decide the redundancy from the cost of losing cooling, not from habit.
• Refrigerant and regulation. Choice affects availability, service and future phase-down exposure.
• Site conditions. Hot ambient design temperatures, water quality, noise limits at the boundary, rooftop or basement location, and crane access all change the scope.
• Capacity and diversity. A chiller sized on connected load, not diversified load, costs more and runs at poor part-load for years. The chiller capacity calculator gives a first diversified tonnage.

Efficiency class: what the energy code asks

The Bureau of Energy Efficiency's Energy Conservation and Sustainable Building Code 2024 (ECSBC) applies to commercial and office buildings with a connected load of 100 kW or contract demand of 120 kVA or more, where adopted by the state. It is not written for industrial process cooling, but its chiller provisions are a useful benchmark for any buyer. For a compliant building it asks for a minimum BEE 3-star rated chiller. Where cooling or recycled water is available it prefers water-cooled chillers, and for cooling loads of 530 kWr or more it restricts air-cooled capacity to 33% of the installed chilled water plant (excluding standby), unless the local authority requires more. It also requires chillers to be rated at full load and part load to IS 16590, and it asks for plant controls that optimise chillers, pumps and tower fans in plants above 1,500 kW cumulative capacity or with more than three chillers.

The code also sets a whole-plant measure: for a water-cooled chilled water plant, annual electricity of chillers, chilled and condenser water pumps and cooling tower fans per unit of cooling delivered. The maximum thresholds are 0.24 kWh per kWh of cooling for ECSBC, 0.21 for ECSBC+ and 0.19 for Super ECSBC. One tonne of refrigeration is 3.517 kW, so these are about 0.84, 0.74 and 0.67 kW per TR for the whole plant. That plant-level number is more useful than a chiller IPLV on its own, because pumps and towers often waste what a good chiller saves. The code's thresholds are for the whole year, as simulated; use them as targets to ask bidders to meet, not as guarantees.

Lifecycle: the arithmetic that beats the purchase price

Annual energy for a plant is: TR × 3.517 × plant kW per kW of cooling × equivalent full-load hours. As an illustration only, take a 200 TR plant and an assumed 2,500 equivalent full-load hours a year. At the ECSBC threshold of 0.24, the plant uses about 422,000 kWh a year. At the Super ECSBC threshold of 0.19, it uses about 334,000 kWh, a difference of roughly 88,000 kWh a year. Multiply the difference by your tariff and by the years of operation, and compare it with the extra capital cost of the better plant. If the extra capital is recovered in a few years of energy, the efficient plant wins; if not, it does not. The hours and tariff are your own numbers to replace.

Add maintenance, water treatment, spares, and the cost of a stoppage, and the lifecycle picture is complete. The VRF and chiller lifecycle cost calculator does this for capital, energy and maintenance, and the chiller retrofit savings calculator tests replacing an existing plant. For the choice between chillers and VRF, see our note on VRF versus chiller for Indian buildings.

Comparing bids on equal terms

Look at part load before full load. Most comfort-cooling plants run well below design capacity for most of the year, so a chiller with a good full-load figure and a poor part-load figure will disappoint. The ECSBC defines the integrated part-load value (IPLV) as the weighted average efficiency of a chiller at part-load conditions, and says it is the more realistic measure of efficiency over the machine's life. Ask each bidder for both numbers, stated at the same conditions and on the same test basis, and be wary of a datasheet that gives only the better one.

• Ask every bidder to price the same boundary, listing what is excluded.
• Ask for the guaranteed efficiency at stated full-load and part-load conditions, and for the test standard and tolerance.
• Ask for plant-level energy assumptions: pump and tower power, not only the chiller.
• Check warranty terms, spare parts and service response, and who commissions the plant.
• Check the electrical and civil interfaces: who supplies the starter, cables and foundations.

Our HVAC contractor BOQ guide and HVAC RFQ template carry these items into a tender.

How Secured Engineers helps

We design chiller plants in-house, covering load, redundancy, hydraulic design and plant room coordination, and we deliver HVAC, electrical and fire work under one contract with solar if you need it, from our Noida (Delhi NCR) and Ludhiana offices. Fire NOC, CEIG and DISCOM filings are done in-house. The company has delivered 535+ projects across 18+ states, with 89.77% repeat clients. We do not publish a per-TR price; we review budgets and quotes against scope.

See the chiller plant page for the scope, then send your load, drawings or a quotation on WhatsApp, call +91 70099 85817, or ask for a free proposal that starts with a budget review.