Fundamentals
What are the 4 components in a basic refrigeration (Vapor Compression) cycle
What is Evaporator, Compressor, Condenser, and Expansion Device
What is required within an AHU?
What is a Fan, Air, and Air Tunnel.
(Bonus: mixing box, blenders, filters, heating/cooling, fans, humidifiers, ERVS, UV lights)
...add a channel blender?
What is more efficiently mix OA and RA temps before it hits the Coil
What is the typical water delta T in a hot water coil
What is 20 degrees
What's the standard CFM per ton for comfort cooling
Gotta spell it!
This chart helps visualize air properties like DB, WB, and humidity
What is the P-S-Y-C-H-R-O-M-E-T-R-I-C Chart
What are the three different ERV types
What is Wheel, Core, and Loop-Around Coil
...want to have a blow thru vs draw thru configuration?
what is
Blow thru (before): Heat from the fan can help pre-heat. Cooling coil will deliver proper temps
Draw thru (after): Heat from the fan to help post heat
This part distributes refrigerant or water to the tubes within the coil
What is a header
How much OA does an RTU Typically handle?
What is 20-25%
(Bonus: GH can do 60%!)
Define Latent vs Sensible Heat
What is Latent heat is the change in moisture content, Sensible is change in temperature
What distinguishes a MAU from a DOAS?
What is code requirement or space constraints
...want to have the cooling or heating coil first in an AHU?
What is
Cooling then heating: For dehumidification control
Heating then cooling: For pre-heat protection
What are at least three parameters you can change to affect a coils performance?
What is Rows, FPI, surface area, airflow rate, temperature
What Cooling and Heating Supply Air temps do you typically see off of an RTU?
What is ~55 & ~95 degrees
What is the equation for sensible heat?
BTU = 1.1*CFM*delta_T
This feature is used on a DOAS/ERV for pre morning warm up
What is a Recirc Damper
...choose Huntair over Temtrol?
What is upgraded cabinetry options and flexibility
You calculate this by taking the number-of-rows/Serpentine
What is # of Passes
What Sqft/Ton do we standardize on for VRV systems
What is 325 sqft/Ton
Why does Superheat matter in a refrigeration cycle?
What is ensuring proper vaporization & protecting the compressor (No liquid in the compressor!)
Name at least 6 different Heating and Cooling options/type
What is: Evaporative, Packaged DX, Split DX, Chilled Water, Hot Water, Indirect Gas, Direct Gas, Electric, Steam, Heat Pump
...choose a Fan Coil system vs a WSHP system?
What is
Fan Coil = Chiller+Boiler loop, cheaper system, No compressor/less noise
WSHP = More control, more efficient, groundsource loop, cooling tower or domestic cold water loop
What is the equation for calculating serpentine?
What is Tubes in Headers (feeds) / Tubes in Face (high)
AHU's
Louver, Damper, Heating Coil, and Cooling coil FPM?
What is ~800, ~1200-1400, ~750, and ~400 fpm