Offline — reconnect before saving or submitting. Changes on this page have not been sent.
For commercial and industrial refrigeration projects (cold rooms, cold stores, process cooling) — not household fridges, home freezers or appliance repair. Results are planning estimates, not engineering design or safety advice; a qualified refrigeration engineer must confirm sizing before purchase.
Estimate compressor motor power, COP and displacement from cooling duty and operating temperatures. Results are planning estimates, not final equipment selections.
Use this planning tool to compare compressor motor power, COP, displacement and likely compressor family from duty and operating temperatures. It supports NH₃, CO₂, R-448A/449A and propane scenarios, but final selection requires manufacturer software and an engineer's verified load calculation.
Standard engineering assumptions
Free for buyers, no obligation. These figures are estimates, not quotes — our team reviews your request and contacts suitable suppliers on your behalf.
Estimates Only: This calculator is provided for general informational purposes only. Results are approximate and may contain errors, omissions, or outdated information. They do not constitute legal, financial, engineering, tax, technical, or professional advice. Users are solely responsible for independently verifying all calculations, specifications, prices, regulations, and requirements with qualified professionals before making any decisions. By using this calculator, you acknowledge that the website owners, operators, and affiliates accept no responsibility or liability for any loss, damage, or decisions resulting from its use.
Compressor sizing starts from the evaporator duty in kW and the operating COP: shaft power ≈ cooling duty ÷ COP. Typical COP is 3.5–5.0 for chilled duty (−5 °C evaporating) and 1.4–2.2 for frozen duty (−35 °C). Ammonia (NH₃) usually gives the best efficiency for large plants, CO₂ (R-744) suits low-charge and cascade systems.
Motor power (kW) = cooling duty (kW) ÷ COP ÷ motor efficiency · Displacement (m³/h) = mass flow × suction specific volume
Reviewed by ColdMatch refrigeration engineers
Enter refrigeration duty as kW, TR or BTU/h; all three convert to canonical kW before the compressor model runs.
Select a preliminary NH₃ compressor family for 150 kW at −30 °C evaporating and 40 °C condensing.
Planning output: about 56.5 kW motor input and a screw-compressor family; this is not a manufacturer selection.
Illustrative planning result only. Confirm the final design, duty, equipment selection and performance with a qualified refrigeration engineer and supplier quotation.
Compressor sizing
Limitations
This is a preliminary planning estimate based on the assumptions you entered, not a refrigeration-engineering design, a certified load calculation or a quotation. Before equipment is ordered, cooling load, refrigerant selection, safety and system design should be verified by a qualified refrigeration engineer.
Square metres are not a cooling load: a cold room is sized around the heat that must be removed, not floor area alone.
Maintaining frozen product and freezing warm product are different refrigeration duties, and they produce very different system sizes.
Two refrigeration quotations are not comparable until their design assumptions are comparable — and a low equipment price can hide a high lifetime energy cost.
Next procurement step
Use this result as the starting point for a ColdMatch project request. Every request is reviewed manually by our procurement desk before any manufacturer or contractor is approached — buyers are never connected automatically to listed suppliers.
Turn this calculation into an RFQBrowse the matching equipment categoryAI agents may use ColdMatch calculators to structure preliminary cold-storage requirements and RFQs. Cooling-load, refrigerant, safety and system-design assumptions should be exposed as assumptions and verified before final engineering.
From Te, Tc, refrigerant properties and cooling capacity — giving motor power and displacement.
Chilled: 3.0–3.8. Frozen: 1.8–2.4. Blast: 1.3–1.7.
<50 kW reciprocating/scroll; 50–500 kW screw; >500 kW screw or centrifugal.
From the cooling duty and the evaporating/condensing temperatures, the tool estimates the cycle's specific work — which depends on the refrigerant — and the mass flow needed to carry the duty. Motor power follows from mass flow × specific work ÷ motor efficiency, and displacement from mass flow and suction density. Different refrigerants need very different displacement for the same duty.
A vendor sizes from a real compressor map at your exact operating envelope, including part-load steps, oil management and their own margins. This calculator is a screening estimate: use it to check that a quoted machine is in the right ballpark before the supplier confirms the selection.
The full operating envelope — not one point — part-load efficiency, capacity steps, refrigerant availability and service coverage in your country. Ask for absorbed power at each operating point so energy cost can be compared like for like in the TCO calculator.
The smaller the gap between evaporating and condensing temperature, the higher the COP: chilled rooms typically reach 3.0–3.8, frozen storage 1.8–2.4 and blast freezing 1.3–1.7. That is why oversizing the temperature lift — or letting condensing pressure float too high — costs real money every running hour.
Unsure about a term? See the cold chain glossary (CAPEX, OPEX, blast freezing).
We'll send your calculator inputs to a ColdMatch sourcing specialist, who reviews the project before any supplier research begins. No obligation.
Send your requirements. A ColdMatch specialist reviews every request, prepares a brief and introduces suitable suppliers — free for buyers.
Your size, cost and load inputs are copied into the quote form, so you don't type them twice. Nothing is sent until you review and submit.
Free for buyers, no obligation. These figures are estimates, not quotes — our team reviews your request and contacts suitable suppliers on your behalf.
Not sure which tool fits? Open smart search — every question mapped to the right calculator
