VACUU•LAN pumps have motors that draw between 250 and 530 watts. This will generate heat in a closed cabinet, but the heat can be easily managed by planning for convective airflow past the pumps. A common solution is to remove the cabinet backs to permit airflow into the service chase behind benches and fume hoods, and permitting entry of cool room air by way of louvers on doors or recessed cabinet floors to admit air behind doors. Cabinet temperatures should be kept below 40 degrees C (104 F) in order to prevent pump overheating.
One additional note is that pumps equipped with variable speed motors draw much less than rated power in normal lab operations. This significantly reduces heat generation in cabinets.