Page 174 - Solar Power in Building Design The Engineer's Complete Design Resource

144 ENERGY CONSERVATION

LIGHTING

Providing lighting within a building can account for up to 30 percent of the energy
used. There are several options for reducing this energy usage. The easiest method for
reducing the energy used to provide lighting is to invest in compact fluorescent lights,
as opposed to traditional incandescent lights. Compact fluorescent lights use approxi-
mately 75 percent less energy than typical incandescent lights. A 15-W compact fluo-
rescent light will supply the same amount of light as a 60-W incandescent light, while
using only 25 percent of the energy. Compact fluorescent lights also last significantly
longer than incandescent lights with an expected lifetime of 10,000 hours on most
models. Most compact fluorescent lights also come with a 1-year warranty.
Another option for saving money and energy related to lighting is to use torchieres.
In recent years halogen torchieres have become relatively popular. However, they cre-
ate extremely high levels of heat; approximately 90 percent of the energy used by a
halogen lamp is emitted as heat, not light. Some halogen lamps generate enough heat
to fry an egg on the top of the lamp. These lamps create a fire hazard due to the
possibility of curtains touching the lamp and igniting or a lamp falling over and ignit-
ing carpet. Great alternatives to these types of lamps are compact fluorescent
torchieres. Whereas a halogen torchiere used 4 hours per day will consume approxi-
mately 438 kWh in a year, a compact fluorescent torchieres used 4 hours per day will
only consume 80 kWh in a year. If you currently pay $0.11 per kilowatt-hour, this
would save you over $30 per year, just by changing one lamp.

APPLIANCES
There are many appliances used in buildings that require a significant amount of energy
to operate. However, most of these appliances are available in highly efficient models.
Refrigerators Conventional refrigerators are a major consumer of energy. It is pos-
sible to make a refrigerator more effective and efficient by keeping it full. In the event
a refrigerator is not fully stocked with food, one must consider keeping jugs of water
in it. When a refrigerator is full, the contents will retain the cold. If a refrigerator is old,
then consideration should be given to investing in a new, highly efficient, star-rated
model. There are refrigerators on the market that use less than 20 kWh per month.
When you compare this to the 110 kWh used per month by a conventional refrigera-
tor, you can save over $90 per year (based on $0.11/kWh).
Clothes washers Washing machines are a large consumer of not only electricity
but water as well. By using a horizontal-axis washing machine, also known as a front
loader because the door is on the front of the machine, it is possible to save money
from using less electricity, water, and detergent.
Front loaders have a more efficient spin cycle than top loaders, which further
increases savings due to clothes requiring less time in the dryer. These are the types of
machines typically found in Laundromats. The machines are more cost effective than
conventional top loaders. Another option is to use a natural gas or propane washer and
dryer, which is currently more cost effective than using electric models. If you are on