RFI_Answers_for_ATC_Mobile_-_PAT006.pdf

Answers to RFI Questions

HSCG82-17-B-PAT006

Repair Mechninical & HVAC Systems Compsite ATC Mobile AL

1. The plans state that we will run new control wiring, can the existing raceway / conduit be reused?

Answer: If they exist yes.

2. Can low voltage control wire be run plenum above the ceiling? For example, status wire for the New

Occupancy Motion Sensors.

Answer: No, place in conduit or appropriate cable tray. Do not lay on top of ceiling tiles

3. AHU1 shows RH% control in the sequence, but does not show RH% in the points list or in the drawing. Will RH% control be incorporated for AHU1?

Answer: Monitoring and display RH% only, it will not be used to control operation of system.

4. MAU-1

a. What design temperatures for cooling EAT are we to select the equipment with?

Answer: 29 degree F is EAT for heating mode. Dry bulb EAT 92 deg Wet bulb 70 deg

b. The unit appears to be designed for 12,000cfm of OA but only at 300MBH or 480 cfm/ton. This would result in supply air in the mid to upper 70’s and very humid (exact conditions depends on answer to 1.a). We would normally see much higher capacity for 100% OA units in the 170 cfm/ton or 70 ton range. Can the design cooling capacity be confirmed?

Answer: Cooling capacity is confirmed at 300,000 BTU. If the weight of a 70 ton unit can be supported on existing structure this may be considered later by COTR. This is not a design for extreme condition but to allow some relief from extreme temperature.

c. Sheet M103 appears to imply that a packaged unit is desired for MAU-1. Is that the design intent?

Answer: Yes

d. Can we confirm that the desire is for direct fired and not indirect fired gas heat?

Answer: Correction to documents Indirect fired

e. The control schematic shows a return air duct connection. Is that a typo or is there going to be return air connected to this unit?

Answer: No control schematic was given for MAU-1. The only control schematic were for AHU1/2 and

MAU4, which does not show a return duct. Sheet M103 drawing is intended to shows TWO-supply ductwork not a supply and return.

f. Is the scheduled 1”wg pressure drop the ESP for the blower?

Answer: No TYPO, delete requirement

Answers to RFI Questions

HSCG82-17-B-PAT006

Repair Mechninical & HVAC Systems Compsite ATC Mobile AL

5. MAU-3

a. The unit is scheduled at 175,000btu of heat and 1,530 cfm. I am calculating a 105 degree temperature rise at those conditions and 134F supply air. Can this be confirmed?

Answer: NO TYPO: Original design documents stated 175000btu, my calculations has it at 21,413btu.

Use 24,000 btu of heat

b. Can we confirm that the desire is for direct fired and not indirect fired gas heat?

Answer: Correction to documents use Indirect fired

c. Is the scheduled 1”wg pressure drop the ESP for the blower?

Answer: No TYPO, delete requirement

6. MAU-4

a. What design temperatures for cooling EAT are we to select the equipment with?

Answer: 29 degree F is EAT for heating mode. Dry bulb EAT 93 deg Wet bulb 77 deg

b. The unit is scheduled at 168,000btu of heat and 2,000 cfm. I am calculating a 77 degree temperature rise at those conditions and 106F supply air. Can this be confirmed?

Answer: NO TYPO: My calculations has it at 58,912btu. Use 60000 btu of heat

c. Can we confirm that the desire is for direct fired and not indirect fired gas heat?

Answer: Correction to documents use Indirect fired

d. The control schematic shows a return air duct connection. Is that a typo or is there going to be return air connected to this unit?

Answer: Sheet M603 is the control diagram for MAU4. no return air duct is showing, just a room exhaust.

e. Is the scheduled 1”wg pressure drop the ESP for the blower?

Answer: No TYPO, delete requirement

7. There are numerous references to specifications but none have been received. Can we confirm if there are published specifications for this project?

Answer: Yes, see attached