Draft Inducers

Chimney Design Solutions, Inc. offers the most durable and efficient mechanical draft systems available in the United States. Unlike conventional natural draft chimneys and gas vents, mechanical draft systems always provide a safe, constant draft to maximize appliance efficiency. Chimney Design Solutions, Inc.’s mechanical draft systems are available for several applications, including:

  • Gas, oil, or wood-burning
  • Category I and III applications
  • Category II and IV (condensing) applications
  • Building heat appliance chimneys
  • Stack temperatures up to 1000°F continuous

The mechanical draft systems are available in a variety of configurations, including termination- mounted, inline, and 90° change-of-direction.

All chimney fans and power venters are equipped with inverter duty or electronically commutated motors to further ensure product longevity. All of our chimney fans and power venters are tested and listed to UL 378, Standard for Draft Equipment.

For your specific project, please contact our design team to discuss your options.


The CASV is a mechanical draft system used to control and maintain draft for single, multiple or modulating Category I, II, III or IV and light or heavy oil appliances. There are no limitations on its use with these appliances and it shall be used with any type of chimney or stack.

The CASV consists of a single or multiple RSV Chimney Fan(s) and the EBC30, Modulating Fan Control. The EBC30 maintains a constant draft for the heating appliances by modulating the speed of the chimney fan(s). A variable speed drive (VFD) is also part of the system for chimney fans with three-phase motors; the EBC30 controls the VFD, via a 0-10V signal. An add-on board is available for operating chimney fans with single-phase motors. The CASV system is supplied as a complete package with chimney fan(s), control(s), CO monitor, differential pressure transducer, stack probe, and balancing baffles (as required).

During installation the EBC30 automatically detects connections, setting requirements and any add-on devices. The planned draft setting must be entered manually via the control panel. After these steps have been taken, the control will keep the settings in memory. Many other functions can be programmed in the field.

Each appliance is interlocked with the control. A call for heat activates the chimney fan(s) and releases the appliances once an adequate, pre-set draft is established. The sequence is repeated every time a new appliance calls for heat. When an appliance shuts down, the chimney fan(s) will slow down while still maintaining the draft setting. When the last appliance shuts down the chimney fan will operate in post-purge mode for a preset time period.

If the proper draft cannot be maintained due to a power or mechanical failure, the integrated proven draft function will shut down the entire system. During a following call for heat, the Operating Priority function will detect if one or more appliances can be operated safely. If so, the appliance will be able to operate without fan operation. The EBC30 will allow as many appliances to operate as long as a safe draft is available in the chimney/vent system. After two (2) hours, the EBC30 verifies fan operation and, if present, the EBC30 will go back to normal operation. Otherwise, the EBC30 will continue to operate in Operating Priority mode. The self-check is repeated every two (2) hours infinitely. During a period without fan operation, the control is in alarm mode to notify the building.

The carbon monoxide (CO) monitor deactivates the connected equipment when CO levels reach 100PPM. The CO monitor activates an audible alarm (rated at no less than 65dB at a distance of three feet) when CO levels reach 50PPM. A normally open (NO) contact is available within the EBC30 to activate a visual or audible alarm (by others).

If the chimney fan has been out of commission for seven (7) days, the Bearing Cycle Activation function will operate the chimney fan(s) at a low speed for a short time. This is automatically repeated every seven (7) days, if the chimney fan(s) has not been operating.

Any errors detected during operation are either shown via the self-diagnostic panel or on the display.

The system is available in many sizes as shown on the following pages, and virtually handles any heating appliance(s) independent of input/HP.

ETL Listed to UL378 ‘Standard for Draft Equipment’ as well as Canadian Standard CSA3-B255-M81 for Mechanical Flue Gas Exhausters.