HVAC 11a CNST 305 Environmental Systems 1 Dr. Berryman Heating Systems HVAC 11a CNST 305 Environmental Systems 1 Dr. Berryman 11a Heating Systems; Fuels; Boilers; Furnaces; Hydronics, Radiant Heat Chapter 5 (Toa)

Types of Heating Systems

Energy Sources

Circulating Air Systems Must make good cost projections to assure an economical selection Heat distributed by an air stream through a heating unit to supply ducts duct< 200’

Simple Basics

Heating Units - Air Split System - w/ Gas Furnace upflow downflow horizontal

Heating Units (cont.) Single Package w/ electric heating

Water Systems boiler on cooling tower off Heat is distributed by a pumped water system though a heating unit to supply piping Different piping arrangements are used – Hydronic Piping

Boilers Water Tube – Low Fire Box Gasses pass around tubes Responds quickly to load fluctuations. Types range from small (residential) to large (commercial)

Boilers (cont.) Water Tube – High Fire Box

Piping Configurations Series Loop One Pipe Two Pipe Three Pipe Four Pipe One pipe system

Series Loop Maintenance or repair requires shutdown Temp control at each unit impossible # units limited Only heating or cooling

One Pipe System Allows for each unit to be controlled Diverting Tee Allows for each unit to be controlled Limited # of units that can be serviced Needs special fittings Only heating or cooling

Two Pipe – Reverse Return Each unit fed by individual supply branch Each unit can be controlled Flow rates are balanced (heat or cool only)

Three Pipe System Similar to two pipe systems Allows for simultaneous heating and cooling Mixed return Prohibited by some energy codes

Four Pipe System It is actually 2- two pipe systems Allows for simultaneous heating and cooling Separate water return for heating and cooling Most efficient Most expensive – initial cost

Steam Expands 1000 its original state Creates its own transport system No pumps Piping configurations same for water – only at low pressures Operating temps 220 – 250oF About 15 pisg High Pressures (60 – 350 psig) Use heat exchanges Need steam traps

Steam to Water Heat Exchanger Steam in tube Water in tube Circulating pump

Radiant Systems Iron Sectional Fin-tube radiator

Next Time Basics of Air Conditioning 12 Cooling Systems; Refrigerants; Condenser/Evaporator Compressive; Absorption; Evaporative; Chillers; Heat Sinks Chapter 4 (Toa)