HVAC Heating, Ventilation and Air Conditioning -something that you never think about until it doesn’t work properly

Why I don’t care… Won’t some one else take care of it? I’ll hire some one. The engineers are weird. I don’t have a mind for that stuff.

Questionnaire Q: Why do we control temperature? A: Comfort of guests/employees Q: What temperature is comfortable? A: It all depends… Q: How does humidity play a role in temperature? A: relationship between temp and humidity (evaporation)

HVAC – What does it do? Comfort – primary intent of HVAC systems. Building Durability – moisture Health – air exchange – Mold

Basic HVAC Equipment Fans / Blowers Furnace / Heating unit Filters Compressor Condensing units Evaporator (cooling coil) Control System Air Distribution System

FURNACE A/C UNIT Ductwork Heating and Cooling Equipment Temperature & Humidity Controls HVAC System (simplified)

System Types and Common Terms Packaged Rooftop Unit Split System Heat Pump Geothermal Hydronic (water)

Packaged Rooftop Units

Control Devices Thermostats – Manual – Programmable

Heat Pump Operate on simple refrigeration cycle Reversing the cycle provides heating

Economizers Free cooling source: When available, use cool outdoor air instead of mechanically cooled air. 55 o F 80 o F Minimum supply of outside air Normal Operation Outside air dampers are positioned to provide the minimum outside air Economizer Operation Outside air dampers are fully open. Maximum outside air is provided 80 o F 55 o F and up 85% outside air 85% exhaust