Direct-Fired Make-Up Air Units for Commercial HVAC

Air handlers provide outdoor air, filtration and building pressurization

 

Direct-fired air handlers are an efficient piece of equipment to deliver fresh, clean air into a manufacturing space or paint booth area. Air handlers require minimal ductwork and can be installed indoors or outdoors, horizontally or vertically. Air can be filtered (inlet hood and/or filter section) before entering the space. In warmer weather, burner can be turned off to provide free ventilation cooling. 
 
Heaters deliver 100% combustion efficiency with assistance of 30:1 modulating burner. Heavy-duty, robust frame provides unit stability to accept exterior galvanized panels. Panels are attached via bolt and screw construction and fully weatherized for long unit life. Units are available unpainted galvanized or painted finish. 
 

What is a direct-fired air handler?

A direct-fired air handler is a piece of equipment that heats air directly by passing it over an open flame burner within a cabinet. As outside air enters the heater inlet, the colder air absorbs the warmer air as it travels across the heat source. Warm air is delivered into the space with the assistance of a large blower housed within the cabinet, located opposite the burner section. 

Bananza Unit Capacity: 

 Model

 Airflow Range (CFM)

 B-350

 1,000 - 4,000

 B-650

 4,000 -10,000

 B-1000

 7,000 - 14,000

 B-2000

 12,000 - 25,000

 B-3000

 25,000 -40,000


Bananza direct fired air handlers include several standard safety features. A fused rotary disconnect forces a safe power shut-off to occur before new replacement parts are installed or annual maintenance and service occurs. The high temperature limit switch located on the blower housing (alternatively inside the control enclosure) shuts the air handler off if discharge temperature exceeds setpoint. Additional control options such as Carbon Monoxide or Carbon Dioxide Detectors monitor appropriate levels of contaminants for additional safety measures. 

 

Direct-Fired Air Handlers for HVAC Applications

Direct-fired air handlers for the HVAC market provide heated outside air into the space. Based on building needs, air handlers can adequately maintain a pressurized space allowing up to 80% return air for reduced energy cost. All heaters are built to ETL standards per ANSI Z83.18 or Z83.4. 
 
 
Direct Fired Rooftop Air Handler
 
Four basic configuration styles are available. Heaters with a constant discharge air volume include Make-Up Air, Fixed Recirculation and Air Management. Variable Air Volume configuration sustains a variable discharge air volume ranging from 100% to 50%. Regardless of configuration selected, a minimum of 20% outside air is required. Before air is delivered into the space, it can be filtered via an inlet hood or filter section.
 

Direct-Fired Controls

Controls for direct-fired air handlers offer a wide variety of options. Both HVAC and SPRAY-CURE™ remote panels are pre-engineered for ease of use. All remote panels are constructed within a NEMA 1 enclosure. HVAC panels are used for make-up air space heating. SPRAY-CURE™ panels can be used for spray booths, cure applications or spray/cure finishing areas. Analog and digital remote panels are available. 
 
An alternative to a standard remote panel offering is a BMS-Ready control package. This option provides inputs to receive control signals from a customer determined control system. Each BMS input is capable of receiving a 4-20mA or 0-10VDC from the control system. Every package includes fan on/off relay, burner on/off relay, flame failure relay and signal conditioner for burner modulation. For optimum efficiency, Bananza suggests to limit the discharge temperature to 160°F.

 

HVAC Remote Panels

Basic Remote Panel

Basic Remote Panel

Standard Discharge Control Remote

Standard Discharge Control Remote

Deluxe Temperature Control Remote

Deluxe Temperature Control Remote

This control is used for make-up air and space heating. The discharge temperature of the heater remains constant as selected on the selection dial. The burner flame is modulated by a discharge temperature control, which is governed by the remote temperature selector.

FAN ON  / BURNER ON mode:
Heater can operate continuously for building exhaust air replacement and space heating by maintaining a constant discharge temperature.

FAN ON / BURNER OFF mode:
The blower can operate without the burner for summer ventilation.

This control is used for make-up air and day/night heating of the building. The discharge temperature of the heater remains constant as selected on the selection dial. The burner flame is modulated by a discharge temperature control, which is governed by the remote temperature selector. 

AUTO / WINTER mode:
Heater cycles on/off to maintain space temperature as selected on the thermostat.

ON / WINTER mode:
Heater can operate continuously for building exhaust air replacement and space heating by maintaining a constant discharge temperature.

ON / SUMMER mode:
The blower can operate without the burner for summer ventilation.

This control is used for make-up air and total automatic "day/night" heating of the building. A solid-state modulating room Selectrastat fully modulates the burner flame to maintain space temperature and compensate for changing building heat losses or gains. 

AUTO / WINTER mode:
Occupied time: Heater can operate continuously fully modulating Btu/h output to maintain space temperature as selected on the Selectrastat. 
Unoccupied time: Heater cycles on/off to maintain space temperature as selected on the programmable thermostat (night setback).

ON / WINTER mode:
Heater can operate continuously fully modulating Btu/h output to maintain space temperature as selected on the Selectrastat.

ON / SUMMER mode:
The blower can operate without the burner for summer ventilation.

 

Typical Installations:

Roof Mounted-
Roof Mounted Bananza Air Handler
 
Suspended Indoor-
Suspended Indoor Bananza Air Handler

Horizontal On Legs-
Horizontal Bananza Air Handler On Legs

Upright Outdoor-
Upright Outdoor Bananza Air Handler
 

 LEGEND

 OA = Outside Air

 DA = Discharge Air

 RA = Return Air