Total Efficiency & Comfort Package

Three Systems that create Comfort & Efficiency
o Building envelope (walls, windows, doors, insulation)
o Air Distribution System (ductwork)
o Heating & Cooling Equipment


Building Envelope

Obvious effects on ENERGY
o Heat leaking out in winter
o Hot, Humid air sneaking in during the summer

Effects on COMFORT
o Drafts
o Uneven Temperatures throughout the home
o Temperature swings between cycles
o “Sticky” feeling in summer

Air distribution system

Effects on ENERGY
o Leakage in the supply air ducts puts conditioned air into areas that are not
meant to be conditioned (walls, attics, basements, outside)
o Leakage in the return air ducts draws air from unconditioned spaces taking
more energy to heat or cool (attic air in summer= 140 degrees, return air
from house = 80 degrees; attic air in winter= 20 degrees, return air from
house = 65 degrees)
o Humidity removal costs 970 times more than cooling same air 1 degree
o Undersized ductwork can cause system to short cycle on limit or cause
premature compressor failure for air conditioners
o Longer run time costs more in blower motor electricity consumption
o Poorly insulated ducts can transfer heating and cooling to areas not
intended to be conditioned

Effects on COMFORT
o Leaky duct systems have to run longer to heat or cool spaces
– More air movement
– Air Noise
– System Noise
o Leaks in return Draw “sticky” air into home in summer
– Sometimes results in Cool, “clammy” air
– Makes system capacity too small for building
– Can create mold issues
o Leaks in return Draw cold air into home during winter
– Longer system run time
– More air movement
– Makes system capacity too small for building
– Colder air from registers

o Register and grille placement can lead to Drafts in home
o Poorly designed ducts can lead to hot and cold spots throughout the home
– Blower not strong enough to reach farthest runs
– Duct not sized to carry enough heating and cooling to certain
– Duct not sized to carry enough heating or cooling for the entire
– Too many twists and turns in duct make excess resistance to
– Poor fitting design can restrict airflow to entire building
o Poorly Insulated ducts can lead to heating and cooling being transferred to
areas not intended to be conditioned
o Poorly insulated ducts may sweat leading to mold or property damage

Heating & Cooling Equipment

Effects on Energy
o Old and inefficient technology
o Improper operation due to oversizing
o Improper operation due to mechanical or maintenance problems
o Improper application
o Improper installation

Effects on Comfort
o Uneven temperatures due to oversizing
o Hot and Cold temperature swings
o Noise levels
o Cold Drafts in Winter
o Damp, clammy indoor environment in Summer

Other negative effects
o Shortened Equipment Life
o Frequent Breakdowns
o Property Damage
o Overall Inconvenience