How to Choose a Laboratory Water Circulator & Cold Trap

A recirculating water circulator (chiller) and a cold trap solve two different problems in the same workflow: the circulator delivers temperature-controlled fluid to remove process heat, while the cold trap captures moisture and solvent vapor before they reach your vacuum pump. This guide explains how to size each one and when you need both, using Yamato Scientific's CB-100, CF-303Y/CF-313Y, CF-802A and CA-301.

Step 1 — Decide: heating & cooling, or cooling only?

If your application needs a regulated bath that can run warm or cold — viscometry, spectrofluorometry, reaction tempering — the CB-100 is the only circulator in this range with both heating and cooling (−10 °C to 80 °C), in a slim 180 mm-wide benchtop body.

If you only need to remove heat — cooling a rotary-evaporator condenser, a reaction, or an analytical instrument — choose a CF-series refrigerated chiller. These run −20 °C to 30 °C with no heating function, which keeps them compact and efficient for pure cooling duty.

Step 2 — Match cooling capacity to the load

Model	Type	Temp. range	Cooling capacity	Bath / flow	Best for
CB-100	Heating & cooling	−10 °C to 80 °C	—	3.4 L · ~6.8–8.0 L/min	Bench instruments needing warm or cold fluid
CF-303Y / CF-313Y	Refrigerated chiller	−20 °C to 30 °C	~450 W @ 10 °C	3.9 L · ~10 L/min	A single rotary evaporator or condenser
CF-802A	High-capacity chiller	−20 °C to 30 °C	~1320 W @ 10 °C	15.5 L · ~14 L/min	High heat loads or up to 4 evaporators

As a rule, size the chiller so its cooling capacity at your working temperature comfortably exceeds the heat your process rejects, with headroom for a warm room. The CF-802A earns its larger footprint when one chiller must serve several rotary evaporators at once, or when ambient temperatures are high — and it offers an optional in-body solvent-recovery secondary trap.

Step 3 — Plan power and plumbing

CF-303Y is 115 V; CF-313Y is the 220 V version of the same chiller — pick by your available outlet. CF-802A is a 15 A, 115 V unit. All CF circulators connect with a one-touch swivel L-type fitting (10 mm OD hard tube or 9 mm ID hose), have a front-removable intake filter, and include a condensation drain hose. Because the system is closed-circulation, you conserve water instead of running it to drain.

Step 4 — Add a cold trap when vacuum is involved

Any time you pull vacuum on a process that releases moisture or solvent — rotary evaporation, vacuum drying, concentration — a cold trap protects the pump and the environment. The CA-301 is a mechanically refrigerated −45 °C trap that needs no dry ice or liquid nitrogen, captures up to 0.9 kg of condensate, and uses a stainless-steel condenser (with an optional glass trap for corrosives). For oil-sealed pumps it prevents oil contamination; for dry pumps it closes the system so vapors never vent into the lab. Capturing vapor as a frozen solid also keeps evaporation rates high.

Frequently asked questions

Do I need both a circulator and a cold trap?

They serve different roles. A circulator cools the condenser so you collect the maximum solvent; a cold trap sits before the pump to protect it. Many rotary-evaporation and vacuum-drying setups use both. If you only need bench cooling/heating with no vacuum, a circulator alone is enough.

Can one chiller cool multiple rotary evaporators?

Yes — the CF-802A is designed to serve up to four rotary evaporators simultaneously thanks to its ~1320 W cooling capacity and 15.5 L reservoir.

Why a mechanically refrigerated cold trap instead of dry ice?

The CA-301 reaches −45 °C electrically, so there are no consumables to buy, store or replenish, and trapping is continuous and unattended.

What refrigerants do these units use?

The CB-100 uses R-134a; CF-303Y/313Y use R452A; CF-802A uses R410A; and the CA-301 uses a CFC-free refrigerant — all environmentally responsible choices.

Explore the full range: Laboratory Water Circulators · Cold Traps · Rotary Evaporators. In stock at LabSupplies.com — authorized Yamato Scientific dealer, ships from USA.