Your home is a system with three major parts: (1) the structure, (2) the equipment, (3) lighting and appliances.These three parts and all components of these parts work together in a home.For your home to be comfortable and provide you with a healthy and conducive living environment, while using the least amount of energy, it is important that the system with all its parts and components be well balanced.The whole house approach focuses on fixing the trouble spots in your home and increasing its overall energy efficiency.
Let�s take a look at each of these parts:
The Structure
This is called the �Building Envelope� or the �Building Shell� and constitutes the shell that surrounds the home.The components of the shell include: floors, walls, ceilings, roof, doors, windows, skylights, etc.Heat flows in and out of the shell by two mechanisms: transmission and air leakage.Transmission and air leakage occur through four independent pathways: floors and foundations; walls; roofs and ceilings; and fenestration � windows and doors.Heat transmission through the building shell depends on two factors: thermal resistance and surface area.Air leakage in cubic feet of air per minute (CFM) depends on the surface area of the shell�s holes and the pressure difference between the indoors and outdoors.
The Equipment
This is the equipment used to keep the home a comfortable place to live.This includes heating and cooling system including ducting, fans and ventilation system, thermostats, and hot water heaters and storage tanks.
Lighting and Appliances
These are used for creating a comfortable household.Lighting can be indoors and outdoors, and includes sensors and controls.Various appliances are used in a household: cooking range, microwave, refrigerator, freezer, dishwasher, laundry machines � washer and dryer, etc.Besides, there is electrical equipment for entertainment and productivity, such as television, VCR, DVD player, radio, alarm clocks, computers and laptops, etc.
Click Image to enlarge (Source: U.S. EPA)
Click Image to enlarge (Source: U.S. EPA)
What is Home Performance with Energy Star?
(Source: U.S. EPA)
A drafty home,
rooms that are too hot or too cold, and high energy bills are all common issues
for homeowners. Installing a new heating or air conditioning system, buying
replacement windows, or adding more insulation may fix part of the problem. But
the way to better results is through an integrated "whole-house" approach
that looks at your house as a system.
Home
Performance with ENERGY STAR, is a national program from the U.S. EPA and U.S. DOE, which
offers a comprehensive, whole-house approach to improving energy efficiency and
comfort at home, while helping to protect the environment.
How Do I Benefit from Home Performance?
(Source: U.S. EPA)
Home
Performance with ENERGY STAR can help you cost-effectively improve your
home's energy efficiency. Specially-trained contractors evaluate your home
using state-of-the-art equipment, recommend comprehensive improvements that
will yield the best results, and help you to get the work done.They can also help you take advantage of
Federal tax credits for energy efficiency improvements.
A whole-house assessment by a contractor participating in Home Performance with
ENERGY STAR can uncover your home�s performance problems and identify
improvements that, when made together, can greatly improve your home's energy
efficiency and comfort. The contractor can also help you get the work done right
Common Home Problems and
Solutions
(Source: U.S. EPA)
Is your home cold, drafty, or uncomfortable? Do you have high
energy bills? Ice dams? Peeling paint? Excessive dust? Addressing these types
of home problems can make your home more comfortable, and at the same time
improve it's energy efficiency � saving you money on utility bills and helping
to protect the environment too.
High Energy Bills
High
utility bills in summer and winter can often be traced to air leaks in your
home's envelope, inefficient windows or heating and cooling equipment, or
poorly sealed and insulated ducts.
Mold, Mildew or Musty Odors
Water
leaks or high humidity can lead to mold and mildew. This can cause wood rot,
structural damage, peeling paint, and a variety of health problems.
Damp Basement
A damp
basement is commonly caused by moisture migrating through the foundation. As
this moisture evaporates, it increases indoor humidity and can promote the
growth of mold � resulting in an uncomfortable house.
Cold Floors in Winter
Some
types of floor coverings (such as wood, stone, tile, or concrete) will
naturally feel cold on bare feet. However, insufficient insulation or air
infiltration can also cause cold floors.
Drafty Rooms
Cold air
coming into or going out of your house, especially through leaks hidden in the
attic and basement, can cause rooms to feel drafty and uncomfortable.
Dust
Increased
dust could be a sign that it is time to change your air filter or that your
ductwork is not well sealed.
Moisture on Windows
Inefficient
windows or high indoor moisture levels from air leaks can result in
condensation, frost, or pools of water on windows and sills.
Ice Dams
Warm air
inside your home leaks into the attic and will warm the underside of the roof
causing snow and ice to melt and refreeze as it runs off your roof � forming
icicles and ice dams.
Peeling Paint
Peeling
or cracking paint on your home's exterior may be a sign of a humidity problem
or improper paint application.
Hot or Cold Rooms
Significant
differences in temperature from one room to another could be caused by several
factors, including inadequate insulation, air leakage, and poor duct
performance.
Dry Indoor Air in Winter
Air
leaks in your home allow warm humid air to escape and draw in drier colder air.
Diagnosing the Problem
(Source: U.S. EPA)
Rather than focusing on a single component, such as single-paned windows, an
old air conditioning system, or leaky ductwork, a participating contractor will
assess how improvements to all of these components can work together to
provide:
fewer drafts
consistent temperatures across rooms,
better ventilation and humidity control, and
lower utility bills
Common Recommendations
(Source: U.S. EPA)
Sealing Air Leaks and Adding Insulation
Many air leaks in homes are fairly obvious, such as around windows, doors,
and electrical outlets. But others, like those in attics, around chimneys, and
through recessed lighting fixtures, are often the more significant sources of
energy loss in a home. Sealing air leaks is critical to improving the overall
efficiency of your home and will make your heating and cooling system perform
better. Along with air sealing, your contractor may recommend that you add
insulation. Many older homes are not well-insulated, and some have no insulation
at all. Properly installed insulation in walls, floors, and attics provides for
more even temperatures throughout the house and results in a quieter, more
comfortable living environment that is easier to heat and cool.
Sealing Ductwork
Many homes have leaky ductwork and poor air flow, resulting in stuffy and
uncomfortable rooms � regardless of the thermostat setting. The home performance
contractor may recommend sealing your home�s ducts with mastic, metal tape or
spray-on sealant, and balancing the duct system to optimize air flow to all
rooms. Insulating ductwork in attics, crawlspaces, and some basements can also
help to ensure that your home will be more comfortable.
Improving Heating and Cooling Systems
If your furnace or air conditioner is more than 10 years old, your contractor
may recommend that you replace it with a unit that has earned the ENERGY STAR
label. Installed correctly, these high-efficiency units can save up to 20
percent on heating and cooling costs. But when it comes to heating and cooling
equipment, bigger is not always better. A properly-sized unit will make your
home more comfortable by providing more consistent temperatures and better
humidity control.
The contractor should also test combustion equipment, such as your furnace
and hot water heater, to ensure that it is operating and venting properly.
Upgrading Lighting and Appliances
Energy used for lighting and appliances can account for half of your home's
total utility bill. As a result, the home performance contractor may recommend
ENERGY STAR qualified products, such as refrigerators, dishwashers, electronic
equipment, light fixtures, and compact fluorescent bulbs. An energy- and
water-efficient hot water heating system may also be recommended.
Once you�ve taken steps to increase your home's efficiency, you may also want
to consider adding renewable energy systems, such as solar electric
(photovoltaics) or solar hot water, to further reduce your utility bills.
Quality Assurance
(Source: U.S. EPA)
A local Home Performance with ENERGY STAR sponsor (a State Energy Office, utility, or nonprofit energy efficiency organization) is responsible for ensuring that participating contractors maintain high standards for quality. This typically includes providing specialized training for contractors and conducting quality assurance inspections to verify that Home Performance with ENERGY STAR projects get done right.
Acknowledgements:
US-EPA / US-DOE: Home Performance with Energy Star
J. Krigger and C. Dorsi: Residential Energy
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