Buffalo Wild Wings

C. Direct Fired Make-Up Air Unit (MUA or SF-1) Accurex
1. Install direct fired make-up air heaters as scheduled. Units shall be ETL or UL
listed.
2. Units shall be factory assembled and shipped as a complete packaged assembly
and shall include the following:
a. Gas Burner designed to operate with an air velocity of 2,850 FPM across
non-clogging stainless steel air baffles. Burner to be designed to operate
at 100% thermal efficiency throughout the life of the equipment.
Turndown of the burner shall be a minimum of 25:1. Entire width of
burner burns at all times. Burner section shall have adjustable profile
plates for field adjustment of air velocity over the burner. Provide
intermittent ignition assembly.
b. Forward curved, double width, double inlet blower mounted on a solid
steel shaft with self aligning 100,000 hour bearings.
c. Equipment casing to be 16 gauge, G90 galvanized steel around an
integral support frame of structural angle. All panels shall be removable
for easy access. Provide an observation port for the main and pilot
flames. All controls, gas valves and modulating controls shall be
mounted in a vestibule with access doors outside of the air stream.
d. Gas train shall be constructed to meet State Codes, ANSI and IRI
requirements. Gas train shall be selected to operate at 14” W.C. psig
pressure. Regulators to be approved for non-vented service.
e. Temperature controller shall be a ductstat mounted integral to the unit.
f. Provide the following controls:
(1) Airflow switch
(2) Electronic Flame Safety Relay
(3) High Temperature Limit Switch
(4) Starter Interlock
(5) High Gas Pressure Switch
(6) Low Gas Pressure Switch
(7) Adjustable Low Limit
(8) Auxiliary Circuit to shut the unit down on a flame failure
(9) Adjustable burner on/off economizer intake air ductstat
(10) Remote panel complete with operating lights to indicate blower
on and burner on, and discharge air temperature adjustment,
summer-off-winter selector switch.
(11) Audible alarm to signal safety shut-down
(12) Shunt trip circuit breaker in source electrical panel
g. Provide motorized outside air damper that complies with the damper
specification in Section 15800.
h. Unit shall have single point power connection with a fused disconnect.
Provide filter section with cleanable aluminum filter.
10/28/2011 HEATING, VENTILATING AND AIR CONDITIONING
15700-3