How To Size An Industrial Chiller

When To Specify A Custom Or Semi-Custom Industrial Chiller

August 4, 2026

Most industrial cooling needs are met by standard catalog chiller products — and for good reason. Standard units are well-tested, readily available, lower in cost, and supported by established service networks. But some applications have requirements that fall outside what standard products accommodate, and in those cases, custom or semi-custom chiller specification is the right engineering approach.

When Standard Chillers Are the Right Choice

The baseline assumption should be: use a standard product if it can meet the application requirements. Standard products:

  • Are less expensive — custom engineering adds cost that must be justified by application requirements
  • Have faster lead times — standard products ship from stock or short manufacturing queues
  • Are better supported — service technicians, parts availability, and documentation are established
  • Have proven track records — standard products have accumulated operating hours that validate reliability

Applications That May Require Custom or Semi-Custom Solutions

Application Characteristic Why Standard May Not Work
Non-standard operating temperature ranges Very low (-40 degrees F and below) or very high process temperatures may require special refrigerant circuits or heat transfer fluids not available in standard products
Hazardous area electrical classification NFPA 70 Class I Division 2 or Zone 2 classified environments require explosion-proof electrical; not standard on most commercial chillers
Unusual physical constraints Small footprint, specific connection locations, low height for below-grade mechanical rooms, or non-standard voltage/phase requirements
Special materials of construction Stainless steel refrigerant circuits, special alloy heat exchangers, or marine-grade corrosion protection for coastal or corrosive environments
Redundancy within a single unit Dual-refrigerant-circuit designs where each circuit handles 50% of load — a single compact unit with built-in N+1
Pharmaceutical documentation requirements Enhanced documentation packages (Factory Acceptance Testing, IQ/OQ/PQ support, material certificates) not provided with standard products

"Custom isn't for everyone, and it shouldn't be. But when an application genuinely falls outside what standard products provide, it's better to engineer the right solution than to compromise the process."— Justin Thomas, General Manager, G&D Chillers

The Semi-Custom Approach

Many applications that seem to require full custom engineering can be addressed through semi-custom solutions — standard chiller platforms with defined modification packages:

  • Refrigerant substitution: standard chassis with different refrigerant and modified expansion device for unusual operating temperatures
  • Controls package modification: standard chiller with enhanced controls, additional sensors, remote monitoring hardware, or specialized interface protocols
  • Materials package: standard design with stainless heat exchangers or special coatings for corrosive environments

Semi-custom solutions capture most of the benefits of standard products (known reliability, faster lead times, lower cost) while addressing specific application requirements.

Frequently Asked Questions

How much does custom engineering add to chiller cost?

Semi-custom modifications typically add 15-35% to standard product cost. Fully custom-engineered chillers may cost 50-100% more than comparable standard products. In both cases, the premium must be justified by requirements that genuinely cannot be met otherwise.

How long does custom chiller specification and manufacturing take?

Semi-custom modifications may add 4-8 weeks to standard lead time. Full custom engineering typically requires 16-30+ weeks from specification finalization to delivery. Custom projects should be initiated early in facility design to avoid schedule impacts.

> Explore custom and semi-custom chiller options for your industrial application -> Contact us