Green Collar Careers - HVAC System
& Structural Thermal Efficiency
the HVAC system consumes the most power of any of the appliance
groups. Homes built before 1990 tend to be less energy
efficient. Doors and windows are certain to have air leaks, as will
wall socket plates and more. Significant air leaks can effectively
double the load on an HVAC system during extreme weather. For a $300
power bill, that equals about $100. Most door and window seals can be
Few will have programmable controls for the HVAC systems. If the
family is out of the home at work/school 5 days a week, a programmable
thermostat system can realistically reduce the HVAC load by 20% -
thatís net savings of about 6% of the power bill.
Over the last decade HVAC systems have been built with major
improvements in efficiency and are given a Seasonal Energy Efficiency
Rating (SEER). The simple explanation is the power consumption ratio
between a SEER 10 and SEER 18 is 10/18 meaning the SEER 18 will
require 55% of the energy of the SEER 10 to perform the same cooling.
Customers will be reluctant to spend thousands of dollars to upgrade
their HVAC systems. However, the lower the SEER number, the more
you'll be able to save them with the simple steps below.
Unless the mechanicals have been recently updated, the HVAC systems
will be less efficient systems and are likely overdue for a coil
cleaning at the least. The air handler should draw air in through a
filter. Clogged filters restrict the airflow making the compressor
work much harder. The more dust that does get through the air handler,
the more that clings on the evaporator coil, effectively insulating
the core from the air. Dirty evaporator coils can easily drop the
efficiency of an HVAC by 5%, effectively adding 1.5% to the monthly
Likewise on the outdoor condenser coils, build up of grass clippings
and dirt will reduce their efficiency. Also some of the foil fins on
the coils may be damaged from object rubbing against them like yard
tool wheels. Dirty condenser coils can easily drop the efficiency of
an HVAC by 5%, effectively adding 1.5% to the monthly power bill.
Most evaporator and and condenser coils are easy units to service
with a small and powerful shopvac and a few 1/4" nutdrivers/screwdrivers
to gain access. 95% of all the "AC Tuneup" specials the AC
service companies charge $90 for are nothing but cleaning the coils.
A good technician can finish the job in 15 minutes. This is a
very worthwhile action to add to your Home Energy Audit service.
To learn more about door seals and repairs use the search tool below
to look up AC condenser coil cleaning.
Air Leaks Doors and Windows
Door leaks around seals are typically the largest air losses in any
home. Typical door weatherstripping replacement materials cost
under $20 and take less then 10 minutes to replace. This may be
a service you'll want to add to your business, in which case you'll
need an inventory of various seal types. Most door seals begin
to leak after as little as 2 years, and in most cases only have about
a 5 year life. To learn more about door seals and repairs use
the search tool below to look up door
Window leaks are generally more
difficult to detect and repair, and usually account for much less
leakage then doors. If a home has evidence of warped window
frames, the best solution is to recommend replacement. Windows
that let sunshine in also let heat in. In southern climates this
can add significantly to the load on an air conditioner, while
contributing much less of the heat in the winter. A simple
estimate of how much solar heat these windows are adding add up the
square footage of the windows and the number hours before and after
noon they receive direct sunlight. Multiply each square-foot *
the number of hours (maximum of 6 hours) * 8 Watts to get the number
of watt hours per day of heat. For example a home with 200
square feet of windows for 8 hours a day would equal:
(200 * 6 Hours
* 8 Watts) / 1000 = 9.6 kWh per hot summer day!
film will reduce the summer heat by 60% or 5.7 kWh per day.
Conversely, on the same home it would add 2.9 kWh in the winter months
to an electrically heated home. Solar Film is a fairly easy
product to install and you may want to add it to the list of services
you'll perform. To learn more about solar film and application
use the search tool below to look up Solar
Insulation provides a barrier between the inside and outside climates
however its often overrated for the actual effectiveness. While
attic heat losses are important with winter heating bills, in the
summer fiberglass insulation is much less effective due to the infra
red heat energy. Radiant barriers offer a huge improvement and
can be relatively easy to install in attics that have access.
Radiant barrier materials generally cost about $0.25 per square foot
and take roughly 8 hours to install in a 2000 square foot attic.
simple estimate of how much solar heat radiant barriers are blocking
add up the square footage of the attic space with radiant barriers and
the number hours before and after noon they receive direct sunlight.
Multiply each square-foot * the number of hours (maximum of 8 hours) *
4 Watts to get the number of watt hours per day of heat. For
example a home with 2000 square feet of windows for 8 hours a day
(200 * 8 Hours * 4 Watts) / 1000 = 6.4 kWh per
hot summer day!
To learn more about radiant barriers and
installation use the search tool below to look up