GOOGLESCHOLAR: Weatherization Assignment 6
whieso
overview_6.rtfOverview
Lighting and Appliances
Making the lighting and appliances in a home more energy efficient is an important part of the weatherization process. Exchanging inefficient light bulbs for newer, energy efficient versions is easy and, in most cases, inexpensive.
Exchanging appliances for newer, more energy efficient ones is usually worth the effort, although some appliances, such as ovens and stovetops, do not use enough energy to warrant being replaced.
Learning Objectives
Upon completion of this module, you should be able to:
7A
evaluate the best types of artificial lighting.
7B
create different applications that bring natural light in a space.
7C
discuss which types of appliances are the most energy efficient.
Module 6 Reading Assignment
Krigger, J., & Dorsi, C. (2012). Residential Energy: Cost Savings and Comfort for Existing Buildings (6th ed.). Helena: Saturn Resource Management, Inc. Chapter 7.
Supplemental Reading Assignments (Required):
Division of energy resources (2010). Appliances, lighting, electronics an energy guide to help select and operate efficient devices for your home . Minneapolis, MN, (pp. 1-32).
Institute for electric efficiency. (2009, December). Assessment of electricity savings in the U.S. achievable through new appliance/equipment efficiency standards and building efficiency codes (2010-2020) . Washington, D.C.: The Edison Foundation, (pp. 1-42).
Lecture Notes
Lighting and Appliances
Anything that draws electrical power is referred to as a load. Part of weatherizing a home includes minimizing the loads in the home in order to lower energy bills and maximize energy efficiency.
Artificial Lighting
Artificial lighting is provided by electricity, fixtures, and bulbs. Artificial lighting is a big contributor to high energy costs. It can contribute as much as 50 percent of the total energy costs of a home.
Lynn Clement of Focus on Energy once said, “If every American household replaces light bulbs in their five most frequently used fixtures with ENERGY STAR compact fluorescent bulbs, we could save more than $8 billion in annual energy costs and prevent greenhouse gases equal to the emissions of more than 10 million cars.”
Since lighting accounts for 20 to 25 percent of U.S. energy consumption, the move to more energy efficient lighting is very important.
Types of Lighting
There are three primary uses, or functions, for lighting in homes: task, ambient, and accent. Task lighting provides light to perform work. Ambient lighting may include light that is used for work but also includes lighting for safety and security. Any lighting used for contrast or ambiance is accent lighting. There are many different types of artificial lights available for residential uses.
Types of Artificial Lighting
Incandescent
Fluorescent
Compact fluorescent
High-intensity discharge
Halogen
Light Emitting diodes
Full Spectrum
Recessed Lights
Incandescent Bulbs
Incandescent bulbs, which are also referred to as A-type bulbs, are the oldest, most prevalent, and least expensive type of lighting. Incandescent bulbs function by allowing an electric current to pass through a thin filament and heat it until it produces light. The enclosing glass bulb prevents oxygen from reaching the filament because oxidation would destroy it.
An incandescent light bulb
Unfortunately, incandescent bulbs are the most inefficient type of bulb available by far. Only 10 percent of the energy used by an incandescent bulb is actually converted to light. The other ninety percent of the energy emitted by incandescent light bulbs is in the form of heat. The average life for one of these commonly sold bulbs is usually between 1,500 and 2,000 hours. However, there are some long-life bulbs manufactured today.
A house that is full of incandescent light bulbs will require that the air conditioner work constantly to keep the temperature down. There are movements throughout the United States to discontinue the sale and use of these light bulbs because of their extreme inefficiency.
Fluorescent Bulbs
Fluorescent bulbs have been employed for both residential and commercial use for many years. The original 4- and 8-foot long, round tubes were termed T-12s and were about an inch and a half in diameter. Newer and more efficient T-8 tubes are only an inch in diameter. The newest T-5 bulbs are even smaller than the T-8s. The 4-foot tubes are normally 40-watt and the 8-foot tubes are normally 75-watt.
Compact Fluorescent Bulbs
CFLs come in two types: pin type and screw-in. Pin type compact fluorescents require a converter or the replacement of the lighting fixture before they can be installed. Screw-in compact fluorescents are made to replace incandescent bulbs in almost any normal light fixture. CFLs come in all types of bulbs including lamps, reflectors, candelabras, and outdoor bulbs, and some are even dimmable. The most common CFLs found in almost all stores are spiral, screw-in bulbs.
A screw-in compact fluorescent light bulb
When creating a more efficient lighting scheme for a home, the weatherization service provider should consider using compact fluorescent light bulbs (CFLs). CFLs are the most energy efficient type of bulb available and are becoming the bulb of choice for the replacement of incandescent bulbs when tubes cannot be used. Exchanging incandescent bulbs for CFLs is one of the easiest ways to weatherize the lighting in a home.
Compact fluorescent bulbs use less power, have a longer life, and are more expensive than incandescent bulbs. However, because of their longer life span, which is about 10 times longer than an incandescent bulb’s life span, CFLs save in energy costs.
Effects of Compact Fluorescent Bulbs
Produce 75 percent less heat and cut costs associated with cooling the home
Use less energy and last longer
Save money on energy costs
A typical 100-watt incandescent bulb can be replaced by a 25-26 watt CFL, which will fit easily into almost all lamps and light fixtures in today’s homes. A weatherization service provider can find replacement CFLs that provide the same color of light and the same amount of light while using three to four times less energy than an incandescent bulb. This cuts the lighting costs of a residence by about 75 percent.
Some CFLs still take a few seconds to warm up before they reach full brightness. The weatherization service provider should be familiar with these bulbs when he or she installs them and should consult the homeowner as to whether he or she minds the warm up period.
There are certain places in the home that are ideal for the use of compact fluorescent bulbs.
Ideal Rooms for CFLs
Family room
Living room
Kitchen
Dining room
Bedrooms
Outdoor lighting
One disadvantage of CFLs is that they do contain a small amount of mercury and should be recycled. Also, some caution should be taken if a bulb is dropped and manufacturer’s recommendation should be referenced.
High-Intensity Discharge Lamps
High-intensity discharge lamps have the highest efficacy and are the longest lasting of any type of bulb. Efficacy is the number of lumens or light output produced per watt of electricity used. These lamps save between 75 percent and 90 percent of energy costs compared to incandescent bulbs.
Mercury vapor lamps are the oldest type of high-intensity discharge lamp. Lamps that provide 50 lumens per watt have been primarily used for street lighting.
Metal halide lamps are similar in construction to mercury vapor lamps but have a higher light output, more lumens per watt, and better color. These bulbs are used for indoor lighting in gyms, sports arenas, convention centers and other similar types of buildings, and outdoor applications.
High-pressure sodium lamps are also a type of high-intensity discharge lighting. These lamps provide 90 to 150 lumens per watt and are becoming very popular for outdoor lighting because they provide a warm, white light. However, they do not provide exceptional color rendition.
A weatherization service provider can replace older mercury vapor lights with metal halide or high-pressure sodium lamps in order to achieve better energy efficiency.
Halogen
A halogen light bulb is actually an incandescent light with a tungsten filament that is sealed into a compact transparent envelope. The envelope is filled with an inert gas and halogen. The halogen increases the life span of the bulb to twice the life span of an incandescent lamp.
Light Emitting Diodes
A light emitting diode (LED) is an electronic light source that works based on a semiconductor diode. When an LED is on, electrons combine with holes and light energy is released. These lamps offer many advantages over other, older light sources including lower energy consumption, longer life span, greater strength, compact size, and faster switching. LEDs are more expensive and require more current and heat management than other light bulbs.
Full-Spectrum
Full spectrum bulbs span the electromagnetic spectrum from infrared to near-ultraviolet and are meant to simulate natural light. These bulbs can be compact or tube fluorescent, incandescent, or halogen.
Recessed Lights
If recessed lights are installed in a ceiling with a below-grade space behind it, such as an attic, use only Underwriters Laboratory (UL) approved fixtures that are airtight, are Insulation Contact (IC) rated, and meet American Society for Testing and Materials (ASTM) E283 requirements. This helps minimize air leakage that can raise energy costs.
Lighting Controls
Regardless of the implemented lighting strategies, using lighting controls is important for reducing energy costs and increasing comfort. Lighting controls include occupancy sensors and timers that save energy and money. Lighting controls help provide the amount of light that is needed, where it is needed, and when it is needed. A weatherization service provider can use lighting controls everywhere in a home to minimize the cost of providing lighting.
There are several lighting control systems that are designed to maximize lighting.
Lighting Control Systems
Timers are programmable systems that can turn lights on or off at specific times.
Infrared sensors detect human body heat and can turn lights on and off as people enter or leave the sensor’s control area.
Daylight sensors turn light on and off based on whether or not natural light is available.
Motion detectors, photo sensors, and timers should be used as lighting controls in less frequently used areas of the house.
Light Use
When examining the lighting scheme in a home, the weatherization service provider should note places where light trespass and light pollution occur and make adjustments to minimize or completely remove these instances of waste. Light trespass occurs when landscape and building lighting fall onto neighboring buildings and land. Not only is this energy inefficient, it detracts from the quality of life for neighbors and may adversely affect wildlife.
Light pollution occurs over urban areas and prevents people from viewing the night sky. Light pollution in Los Angeles is particularly problematic, although the negative effects are more psychological than physical. All the light that is visible in the nighttime cityscape may be beautiful, but it equals wasted energy.
Daylighting
In addition to maximizing the energy efficiency of a home’s artificial lighting scheme, a weatherization service provider may incorporate some aspects of daylighting into a project. Daylighting is the practice of placing windows, other openings, and reflective surfaces so that natural light provides effective internal illumination. Natural light is provided by the sun. The goal of using daylighting is to maximize visual comfort and reduce energy usage.
The use of daylighting increases property values and saves money in the long run. Not only does daylighting reduce the lighting load, but humans are healthier and happier in natural light.
Example: On a partly cloudy day, a room illuminated with natural light gets brighter or darker as a result of the moving cloud cover. Research has shown that humans respond favorably to this dynamic because it makes them feel like they are outdoors.
In schools, studies have shown that test scores are higher for students who learn in an environment that includes natural light. In commercial facilities, employees report less stress and show better workplace performance in an environment that includes natural light.
It is important to consider that the installation of some daylighting elements, such as windows, is expensive. In addition, although daylighting lessens the lighting load, it may increase the cooling load and, thus, fail to reduce costs.
Common Ways to Provide Daylighting
Windows
Skylights
Awnings and shades
Solar light tubes
Fiber optics
Windows
Windows and their capacity to let hot and cold air into a room were discussed in Module 4, so they will only be discussed briefly here. Windows are the most common method used to allow natural light to come into an interior space. One drawback of using windows is the fact that they do allow penetration of outside air and the escape of conditioned air.
Skylights
Skylights are unique in the world of illumination. A skylight is basically a hole in the roof. Skylights allow natural lighting into an interior room without compromising the privacy of the building’s occupants. Windows, on the other hand, allow natural light to flood into a house and they allow people to see through the window into the building.
The Department of Energy recommends that a skylight be installed just above the surface of the roof—not below. Along with the skylight there should be a curb with flashing. All joints should be tightly sealed. A weatherization service provider should make sure to optimize the spacing of skylights if multiple skylights are to be installed.
Skylights can provide ventilation if the weatherization service provider and occupants agree to install an operable skylight. These skylights are designed with a hand-crank that opens the skylight to let air in. These skylights typically have a screen that keeps out bugs, leaves, and other outdoor elements. Since hot air rises, installing an operable skylight may be a good way to allow hot air to escape and passively cool a room.
Some skylights can be operable to allow additional ventilation in a home.
Awnings and Window Shades
In a typical home, energy is lost through glass doors and windows. On a hot day, more energy comes through one square foot of glass than through an entire insulated wall. Solar radiation through glass is responsible for approximately 20 percent of the load on an air conditioner.
Properly chosen and installed awnings can substantially increase energy savings. Studies have shown that a fabric awning can reduce heat gain by 55 to 77 percent depending on the orientation of the window. This is because it blocks sunlight from directly entering a space. However, awnings do allow indirect light to enter a space, which is why they are sometimes included in daylighting schemes. In the winter when awnings are retracted, the direct sunlight can help light and warm the space.
Window shades work in essentially the same way as awnings. They let light into the space while preventing direct rays from the sun and, thus, lower cooling costs. In most climates, they are most effective when used on the south side of the building where the sun’s rays are the strongest. In the coldest climates, window shades may be detrimental to the heating of the building using the sun’s heat.
Solar Light Tubes
Solar light tubes work by collecting outside sunlight, transporting it, and distributing it into the home. Solar light tubes are inexpensive and very effective. Solar tubes cost about 1/10th of the cost of a skylight.
Solar light tubes are round and are usually 12 to 14 inches in diameter. These tubular skylights are easy to install in the ceiling of a room that needs illumination, such as bathrooms with no windows or dark interior corners. Light tubes add light but little heat, which means that they do not increase the load on the home’s air conditioner.
Some solar light tubes include a light so that they can provide light during the nighttime hours, as well as during the day. This allows the homeowner to enjoy a lighted space without having light fixtures and solar light tubes in the ceiling.
Fiber Optics
Fiber optic daylight is a relatively new technology that captures sunlight and pipes it to where it is needed. This technology integrates sensors into light fixtures to make them more efficient and to allow for a constant light level within the home. A solar tracking mirror allows light to be captured and concentrated before it is transported through fiber optic lines.
Important Rules
Here are some of the most important rules to consider when including daylighting measures in the weatherization of a home:
- Provide a daylighting scheme that works under the full range of sky conditions at that location.
Consider materials, glazing, infrared (IR) filter, and UV filter in window and skylight selection. Glazing is the coating applied to windows to control transmissivity, particularly spectrally sensitive transmissivity.
Minimize direct beam sunlight penetration into work areas. Diffused light is much friendlier than direct sun. Filters and blinds are effective light diffusers.
Window coverings can be used to make a room more interesting, but a good weatherization service provider uses appropriate materials and placement, as well.
Energy Efficiency of Appliances
In most homes, 90 percent of energy that is consumed by appliances is consumed by the refrigerator, dish washer, and clothes washer and dryer.
Fortunately, like most electronic devices today, huge strides have been made in appliance energy efficiency over the last decade. For example, several years ago a national refrigerator manufacturer earned an award for producing a refrigerator that used about the same amount of energy as a 75-watt light bulb.
Refrigerators
Refrigerators are the largest energy users of all household appliances. They consume 9 to 15 percent of the home’s total energy usage. Newer models generally consume up to half the electricity used by older models. There have been numerous recent improvements to refrigerators: the type and amount of insulation and weather stripping, more effective controls, larger and more efficient coils, and highly efficient motors. A refrigerator with the freezer on the top is generally considered to be the most efficient, followed closely by a model with the freezer below.
Dishwashers
New dishwashers use less energy by using water that is 120ºF instead of 130ºF for washing dishes. This saves energy that would otherwise be used for the washer’s built-in water heater. In addition, different cleaning cycles have been introduced that save water and decrease standby losses in the house water heater.
New dishwashers use less energy by offering different cleaning cycles.
Clothes Washers and Dryers
When it comes to clothes washers, the front loading models are far more energy efficient than the top loading models. They also use less water. In addition, newer models have a higher revolution per minute spin cycle so that the clothes dry more quickly and come out of the washer drier. This means that less energy is required for drying the clothes.
Clothes washers may be rated by one of two systems: the Energy Factor and the Modified Energy Factor. The Energy Factor (EF) describes the cubic feet of clothes washed per kilowatt-hour of electricity. The Modified Energy Factor (MEF) is the same as the EF but also takes drying into account.
One of the major improvements to clothes dryers has been the introduction of temperature and humidity sensing devices that work to prevent over-drying and save 5 to 15 percent of energy consumption compared to older models.
Lastly, electric clothes dryers typically cost $0.15 to $0.20 more to dry per load than gas dryers.
Ovens
A weatherization service provider should be able to tell if an oven or stovetop is older or newer. Older gas ovens and stovetops can be identified by the presence of a pilot light. Newer models have electronic ignition.
The weatherization service provider should take the homeowner’s cooking habits into account before replacing cooking appliances. If the homeowner does not cook regularly, upgrading to a newer, more efficient oven and/or stovetop will not significantly affect energy use or savings. Because ovens and stovetops do not use a large amount of energy, a weatherization service provider most often will not replace the home’s current oven and stovetop.
However, if the oven and stovetop are about to come to the end of their useful life, they may be replaced. In such cases, the weatherization service provider should keep in mind that convection ovens are generally more efficient than conventional ovens.
Appliance Information and Energy Ratings
The model number, serial number, age, and other information about most appliances can be found on the manufacturer’s label. These labels are in differing areas on the units and their location can often be found on the PartSelect website or AppliancePartsPros.com . One can also visit the Kouba-Cavallo Associations, Inc. website for more information.
Information about energy ratings for most appliances can be found on a number of websites.
- Environmental Protection Agency ENERGY STAR program
- Association of Home Appliance Manufacturers (AHAM)
- American Council for an Energy-Efficient Economy (ACEEE)
Required Videos:
Energy consumption is a major portion of any structure’s life cycle. We have already discussed the factors related to a structure’s heating and cooling systems and the importance in maintaining maintenance procedures to ensure that each system is functioning correctly throughout the seasonal changes. Let’s move on and take a look at the lighting and other appliance loads within our structure. It is important within our weatherization thought process that we address the issues and concerns that surround lighting and appliance fixtures that are not energy efficient. Energy Star appliances and compact fluorescent lights (CFLs) or Light Emitting Diode (LEDs) lighting units should be installed to ensure that our structure has become more energy efficient through our new weatherization upgrades. The following YouTube video presentations will provide you with valuable information on selecting and replacing outdated lighting lamps and appliances with more efficient Energy Star units for a better energy management plan within our structure.
The case for energy efficient lighting
The do-it-yourself home energy audit – Part 1
The do-it-yourself home energy audit – Part 2
How to go green: what is passive lighting
Basics of LED energy efficient lighting
Trade secrets – energy efficient lighting
Required Presentations:
Lighting and household appliances
