Installed costs and capital offsets are important economic parameters. The installed cost of electric chillers is significantly lower than comparable heat-driven chillers. Heat-driven Chillers require larger cooling water pumps and towers. Engine driven chillers have a prime mover that costs much more than a comparable electric motor (and has much higher maintenance costs as well). Absorption chillers are much more costly than comparable sized electric chillers.
While the factory price of a chiller unit may be easy to obtain, a more meaningful economic comparison is based on the estimated total installed cost. This figure should include the chiller plus associated cooling tower and condenser water pumps and piping or air-cooled condenser, plus delivery of the equipment to the job site, and installation with interconnecting tower/chiller/pump piping and controls, including the contractor's overhead and profit.
Where any one cost segment is constant for all alternatives (such as chilled water distribution pumps and piping), this cost can be omitted since it will not affect the outcome comparison. In some cases, the comparison is simplified if incremental costs are used; that is, one chiller is considered the base and the other alternatives are assessed at how much more or less they cost. For example if one chiller requires 100 more kW service than another, than the incremental service cost is estimated at $45/kW. That chiller's incremental cost would be $4,500 more than the base unit's cost.
In the absence of current, project specific, installed cost figures, these charts and tables can be used to estimate and compare costs.
The costs shown are typical of large water chiller installed costs including cooling tower with pump piping and installation or air-cooled condenser. They are at nominal tons capacity and HCFC-123 or HFC-134a compatible.
Electric Reciprocating Chillers - Air - and Water-Cooled
Electric Centrifugal/Screw Chillers - Water-Cooled
Absorption & Engine Drive Chillers - Water-Cooled
The values provided reflect new construction in a typical building in a representative U.S. city with median labor rates. For units larger than 1,000 tons, the installed cost per ton declines only slightly on a dollar per ton basis. Costs shown are mid-1995 estimates for a single package chiller. On many installations, multiple units of equal or mixed capacities are used. Again, location, labor rates, rigging, control options, and unit efficiency can substantially affect the actual installed cost, which can vary as much as +25%.
Some gas suppliers will subsidize the higher installed costs of engine-driven and absorption chillers. One way they do this is to absorb a percentage of the cost premium. Others will offer incentives, anywhere from $100 to $150 or more per ton, to reduce the installed cost premium. There is no way to be certain how long these incentives may continue.