Exam 2 Flashcards
The Big Four
Split DX
Roof Top Unit
Air Handling Unit (AUH) / Fan Coil Unit (FCU)
Chiller / Boiler
Where is the condensing unit located in a Split DX System?
Outside
Where are the evaporator coil, expansion device, and fan located in a Split DX System?
Inside
Name the different parts of the condensing unit:
Compressor
Condenser Fan
Condenser Coil
Common size for commercial offices:
25-30 tons
Roof Curb
a device that allows the mounting of the RTU on top of the roof and provides the penetrations for duct, pipe, conduit, etc.
RTUs must have a what installed? Describe it.
Economizer.
Mechanical devices intended to reduce energy consumption, or perform useful functions such as preheating a fluid. It allows up to 100% use of outside air for cooling
What does Texas have to say about Economizers?
The energy code for most municipalities has an exception that allows the installation of RTUs without the economizer
What will happen if the condenser coils on an RTU are damaged?
They will not reject heat very well
What is Francis Hall’s floor area?
40,000 sq. ft.
CSI Section 23 00 00
Heating, Ventilating, and Air Conditioning (HVAC)
Cooling coils/heat exchangers are known as
HX
The chilled water typically exits the HX at about what temperature?
55 degrees F
In a chilled water system, the water is cooled to what temperature?
45 degrees F
Air cooled chiller systems can vary in capacity from _______ tons
10-125 tons
CSI Section 23 64 00
Packaged Water Chillers
The primary component of a typical chilled water loop cooling system
The Chiller
Compressor Types
Centrifugal for large systems (>200 ton)
Screw (150 – 600 tons)
Scroll (5 – 25 tons)
Heat Rejection
Air-cooled condenser
Cooling tower
Zachry Engineering complex cooling load:
About 1,000 tons
What type of HVAC system is recommended for Zachry Engineering complex?
4 water-cooled Chillers each of them distributing the cooling load. That way if one fails, the client would still have some cooling capacity.