If we could show you ways to contribute to
cleaner air, would you be interested?
Surveys show that
concern for the environment is a major issue in the minds of
consumers. That's why you probably have real interest in how you
can contribute to cleaner air.
The natural gas
industry also has a keen interest in environmental matters. We are
proud that natural gas can make important contributions in three
areas of concern - ozone and urban smog, acid rain and global
warming. Government, business, academia and the media recognize
that the increased use of natural gas is an attractive option for
solving these problems.
As a concerned
citizen, you may want to add "contributing to cleaner air" as
another benefit of buying a gas appliance. Gas is America's
cleanest fuel and the natural gas industry looks forward to working
with you to solve pollution problems and to protect our precious
environment.
We hope this Buyer's
Guide for gas heating equipment helps you with your selection.
Enjoy your purchase.
From your friends in
the gas industry, use natural
gas. We'll all breathe
easier.
Annual Fuel Utilization Efficiency
1992 New
Furnace Minimum Efficiency Levels
Energy
Savings Payback (ESP)
Explanation of How Gas Heating Systems
Operate
Conventional
Induced Draft Design
Boilers with Power-Vent and Heat Extractor
Condensing or Recuperative-Type
Furnace
Pulse Combustion Furnace
Combination Water
Heating/Space Conditioning
Proper
Sizing
Making
Your Selection
A.G.A.
Design Certification
Special
Tips
Proper
Mainteance
Energy
Efficient Mortgages
Consumer's Work Sheet
Decisions that affect your comfort and
investment
Are you thinking
about buying a new car or a new heating system for your home? Both
will be investments in your future. You are looking for comfort,
low operating and maintenance costs and a product that will give
you long and reliable performance.
With automobiles an
educated consumer knows the right questions to ask: "What about
emissions? How do anti-lock brake systems work, compared with
standard brakes? How long is the warranty?" and "When should I
schedule service?"
But do you know what
questions to ask when it's time to replace your furnace or boiler,
or buy a new home with a different type of heating system than you
had before?
It is difficult to
decide which brand/model of gas furnace or boiler to buy for your
home. This booklet will help you ask the right questions. It will
also give you maintenance tips to ensure that your system gives the
same quality performance year after year.
You'll find
descriptions of models and features, explanation of terminology,
information on efficiency levels and other facts you will need to
help you decide. Remember, no two houses are the same. They are
constructed differently, insulated differently and maintained
differently. It is suggested that you contact a QUALIFIED GAS
CONTRACTOR or your local gas company to help evaluate the specific
heating needs of your home.
WHY A GAS FURNACE OR BOILER IS YOUR BEST HEATING
BUY
Because your heating
system is usually the largest energy user in your home, it's
important for you to choose one that will give you the best value
over the life of your investment. Because furnaces and boilers
usually last 17 to 20 years, this is an important decision. Within
the last few years, technological advances in heating system
designs have given you more choices.
This brochure
explains how you can compare heating systems' efficiency ratings,
discusses basic new furnace and boiler designs and shows you how to
calculate your savings and payback time.
ANNUAL FUEL UTILIZATION EFFICIENCY
The efficiency
ratings you see advertised on new gas heating systems refer to
Annual Fuel Utilization Efficiency (AFUE), a rating method
developed by the U.S. Department of Energy. The AFUE indicates what
percent of the energy used is converted to useable heat.
The AFUE ratings on
gas furnaces and boilers have improved because new designs allow
the heating units to recover heat that would otherwise be
wasted.
1992 NEW FURNACE MINIMUM EFFICIENCY LEVELS
The National
Appliance Energy Conservation Act (NAECA) of 1987 set minimum
efficiency requirements for central heating equipment, regardless
of the energy used. All furnaces and boilers manufactured after
January 1, 1992, must meet or exceed the minimum efficiency levels
required by NAECA.
Minimum efficiency
levels for other gas applicances that have been set by the National
Appliance Energy Conservation Act of 1987 and their effective dates
are shown in Table No. 1.
TABLE NO.
1
| Product |
NAECA Minimum Standard |
Effective Date |
Duration Yr. End |
| Central
Heating Equipment |
78%
AFUE* |
1992 |
10
yrs. |
| Mobile Home
Furnaces |
75%
AFUE |
9/1/90 |
3.25
yrs. |
| Boilers, Hot
Water (Central) |
80%
AFUE |
1992 |
10
yrs. |
| Boilers,
Steam |
75%
AFUE |
1992 |
10
yrs. |
Standards for direct
heating equipment, which includes wall furnaces, fan and gravity
type furnaces, floor furnaces and room heaters, go into effect in
1990 for a period of five years. The minimum efficiency standards
range from 56 percent to 74 percent depending on the type and size
of the unit.
Notes:
* AFUE is Annual Fuel
Utilization Efficiency, determined in accordance with Department of
Energy test procedures.
ENERGY SAVINGS
Because of the higher
efficiency requirements of new furnaces and perhaps the need for a
new venting system, consumers can expect to pay more for the
purchase of their heating systems. However, over the life of the
unit, a high-efficiency gas unit will help pay for itself because
of the annual savings in operating costs or the "Energy Savings
Payback" (ESP).
ESP is simply the
money you save on energy used during the lifetime of your
energy-efficient gas appliance. The more energy-efficient the
appliance, the less money you spend on monthly utility bills. When
comparing your older model of gas equipment with one of the new
energy-efficient gas furnaces, the ESP can help pay back some of
the costs of the new furnace. When shopping for appliances, don't
look just at the price tag, also consider the ESP.
For example, compare
furnace X (your old 63 percent furnace) and Y (a new 94 percent,
high-efficiency gas furnace), assuming a gas cost of 65 cents per
therm* (See Table No. 2).
TABLE NO.
2
| Old vs. New |
Estimated
Annual Fuel Cost* |
Existing Furnace X
Conventional (63%) |
$638.00 |
New Furnace Y
High-Efficiency (94%)
Annual Savings |
$426.00
$212.00 |
Your annual savings
with the high-efficiency furnace would be $212.00. Over the
lifetime of the furnace (20 years), your estimated savings would be
$4,240 over the older 63 percent AFUE furnace.
Please refer to
the consumer's work
sheet.
Because of regional
weather differences and cost of gas, be sure to ask your local gas
company for correct amount of therms used during the year and local
cost of gas.
This example is based
on a region of the country that requires 2,000 heating load hours,
and has a 60,000 and 50,000 Btus/ hr input assuming a gas cost at
65 cents per therm, respectively. Homes located in colder climates
will have higher costs for all types of equipment.
EFFICIENCY
RATINGS MAY VARY SLIGHTLY DEPENDING UPON THE EQUIPMENT
SIZE.
Energy efficiency is
achieved whenever heat loss is reduced. An older conventional
furnace achieves from 60 - 65 percent efficiency. Typical
efficiencies for mid-range furnaces are from 78 - 83 percent. The
new generation of high-efficiency equipment can achieve up to 96.6
percent AFUE.
Be sure to ask your
local gas company, heating contractor or dealer for the EnergyGuide
fact sheets. The Federal Trade Commission (FTC) requires dealers to
have such fact sheets for each natural gas, oil and propane furnace
and boiler. Each fact sheet gives the AFUE rating for a furnace and
the ratings for the most and least efficient furnaces of the same
size and fuel type. The higher the AFUE number, the more efficient
the furnace.
The fact sheet also
helps you estimate the annual operating cost for each model. To do
that, you need to know your local gas rate and BTU (British thermal
units)-per-hour heat loss of your home. The current gas rate can
usually be found on your monthly gas bill, or you can call your
local gas utility. Your heating contractor can calculate the heat
loss of your home. With this information, you can use the chart on
the fact sheet to find the estimated annual operating cost for the
furnace you are considering.
ENERGYGUIDE
On the following
pages are brief descriptions of the basic types of gas heating
systems now available. We suggest that you investigate the
purchase, installation and operating costs of a variety of models
before making a decision. Then obtain bids from two or more heating
contractors before you buy.
AUTOMATIC
IGNITION DEVICES
One feature of the
new high-efficiency systems is the automatic ignition device.
Sometimes called an intermittent ignition device 111D), this
component replaces the constantly burning pilot light.
The device works very
much like an automobile spark plug. Whenever heat is called for by
the thermostat, the 11D produces a spark to light the pilot, which
in turn lights the heating system's main burner. By not using any
gas between ignition cycles, this dependable component conserves
the fuel that would be used by a constantly burning pilot
light.
HOW YOUR
HEATING EQUIPMENT WORKS
Basically home
heating equipment consists of:
- A burner
through which gas is delivered and
burned.
- A heat
exchanger where the heat produced from the burning gas is
transferred to the distribution system (either air or water) that
moves the heat to the location where it is
needed.
- A vent
pipe or flue that exhausts the byproducts of combustion (such as
water vapor and carbon dioxide) to the outside of the
home.
CONVENTIONAL
FURNACE CUTAWAY
The illustration
shows a conventional warm-air furnace. The furnace uses natural or
propane gas and air for burning the gas to provide heat to the heat
exchanger. Circulating air (or water, in the case of a boiled flows
through the heat exchanger where it is heated and then circulates
throughout the house.
For venting, make-up
air is drawn info the vent at the draft diverter. This air mixes
with the hot exhaust gases and travels through the vent and out the
chimney.
Because of the 78
percent AFUE efficiency requirement that will take effect in 1992,
new mid-efficiency upflow gas furnace technologies are being
introduced into the market.
One of these new
designs includes a technologically advanced burner box, atmospheric
venting, and a choice of pilot systems. These new systems will
easily allow for change-out or replacement. Atmospheric % venting
allows more flexibility in the venting systems because no induced
draft blowers are required. Ask your dealer for more
details.
INDUCED-DRAFT
DESIGN FURNACES (83 PERCENT AFUE)
Warm-air furnaces
featuring this design have higher heating efficiencies and use less
gas than conventional models.
Conventional furnaces
draw air through an opening at the front of the furnace and at the
flue to create a natural draft. Induced-draft furnaces use an
automatic fan system to draw the combustion products into the flue,
improving burner efficiency. The fan and a specially designed heat
exchanger work together to reduce excess air and extract heat
normally lost up the chimney.
The improved design
of the heat exchanger can extract 1500 or more of heat from the
same amount of gas burned by a natural draft furnace.
Venting for this
furnace can be done through a chimney or, for some specific models,
through the use of a direct through-the-wall vent.
BOILERS WITH
POWER-VENT AND HEAT EXTRACTOR (87 PERCENT AFUE)
The power-vent design
system provides positive venting through the narrow flue sections,
resulting in rapid heat transfer to circulating water, increasing
heating efficiency and lowering fuel consumption.
As shownin
Illustration No. 3, flue gases are pulled through the boiler
sections and the heat extractor before being discharged info the
venting system. A flue gas close-off valve retains heat in the
boiler when the power vent is not operating.
A chimney is not
required for venting. Direct throughthe-wall or roof venting can be
used with the powervent design.
CONDENSING OR
RECUPERATIVE-TYPE FURNACE (85 percent or higher AFUE)
This type of furnace
is a modification of the conventional warm air furnace design.
However, it operates at significantly higher heating efficiencies
and uses less fuel.
The recuperative
furnace has two heat exchangers: a direct-fired unit and an unfired
unit. Hot flue gases produced by combustion are drawn through the
heat exchanger and recuperative section, and then vented to the
atmosphere by a small fan. No chimney is necessary since the flue
gases are vented directly outside.
Efficiency is
increased because additional useable heat is captured in the
recuperative heat exchanger (unfired unit). This unit condenses the
available water vapor and uses the forced draft fan to reduce the
loss of heated air from the home when the furnace is not
operating.
When water vapor in
the flue gases is condensed, it releases additional heat for use in
the home. The water is disposed of by a condensate
drain.
Q.
What is a condensate drain? A. Because high-efficiency
furnaces cool flue or exhaust gases to temperatures between 1000F
and 1450F, water vapor is condensed to a liquid in the heating
process. A disposal drain must be provided with the
furnace.
Q.
Is special venting needed because of this
condensation? A. Because furnace condensation is
slightly acidic, special plastic PVC pipe venting is
required.
PULSE
COMBUSTION FURNACE (94 - 97 percent AFUE)
Although this
equipment is similar in appearance and installation to a
conventional furnace, the combustion process is completely
different. No heated air from within the building is lost in the
combustion or the venting processes, because all combustion air is
taken from the outside.
Pulse combustion
furnaces and boilers operate reliably at exceptionally
high-efficiency levels and use much less gas than conventional
units.
Here is how the pulse
combustion process works:
- Gas and
air enter and mix in the combustion
chamber.
- To start
the cycle, a spark is used to ignite the gas and air mixture. (This
is one pulse.)
- Positive
pressure from the combustion process closes flapper valves and
forces exhaust gases down the tailpipe.
- Exhaust
gases leaving the chamber create a negative pressure. This opens
the flapper valves, drawing in gas and
air.
- At the
same time, part of the pressure pulse is reflected back from the
tailpipe. Residual heat in the combustion chamber causes the new
gas and air mixture to ignite. No spark is needed. (This is another
pulse.)
- There
are 60 to 70 pulses per second. Each pulse produces 1/4 to 1/2 Btu
of heat using about 0.0003 cubic feet of natural gas. The force of
these series of pulses creates great turbulence, which forces
products of combustion through the entire heat exchange assembly
and results in maximum heat transfer.
- Exhaust
gases pass out of the main heat exchanger and into a secondary heat
exchanger coil. Filtered air is forced across these heat exchangers
and distributed through the home.
- A small
diameter plastic pipe replaces the conventional furnace flue and
chimney, and allows for condensate to empty into floor
drains.
PULSE
COMBUSTION BOILER (90 PERCENT AFUE)
The pulse combustion
boiler works in much the some way as the pulse combustion furnace.
The main difference is that the heat from the combustion chamber is
transferred to water that is then distributed throughout the
home.
COMBINATION
WATER HEATING/SPACE CONDITIONING SYSTEMS
This innovative,
compact and efficient space-conclitioning and water heating system
requires only the space of one unit. As a result, it's ideal for
installation in small areas. One natural gas burner now does two
jobs.
These
energy-efficient systems are designed primarily for use as a
forced-air heating system, but can also be adopted for new hydronic
baseboard systems. The water heater provides domestic hot water
throughout the house. To provide heating, the circulating pump,
controlled by a wall thermostat, sends hot water through the
heating system where the water heats a coil. A fan in the air
handler then blows air over the heated coil. The warmed air is
distributed to the house through ducts. This type of system can
also be used with hydronic heating by circulating hot water through
a radiant heating system.
Properly sized, these
systems can provide adequate space and water heating for homes in
any part of the country.
COMBINATION
UNITS ELECTRIC TO GAS CONVERSIONS
A new hot water
conversion system is available that modifies an electric water
heater for natural gas. This system incorporates a self-contained
gas burner located outside the home to heat and circulate hot water
to an existing electric water heater. To convert an existing
system, a separate circulation system is installed that consists of
a hot water coil that serves as a heat exchanger, water supply and
return lines from the hot water storage tank and a water pump. The
pump is electrically connected to an existing household thermostat.
The hot water coil is installed in the existing air handling
system. When the thermostat calls for heat, the water pump will
draw hot water out of the storage tank and circulate through the
heat exchanger. Using the same fan that is part of the existing
furnace, the heat exchanger transfers the heat energy from the
water to the air. The system gives home owners who were unable to
convert due to venting and space constraints another
option.
MOST
EFFICIENT HEATING/COOLING COMBINATION
The most efficient
heating and cooling with a warm air system can be obtained with a
high-efficiency gas furnace and energy-efficient central air
conditioner. This combination delivers maximum year-round comfort
at minimum operating and maintenance costs.
One reason this
combination works so well is that each component is specifically
designed to perform only a single function - either heating or
cooling. As a result, all design improvements are concentrated on
upgrading the performance of that function. Since they are separate
components, the proper size model of each can be selected for a
given household's heating and cooling needs.
PROPER
SIZING
The size of a furnace
or boiler refers to its heating output capacity rather than to its
physical dimensions. The capacity of a heating system is measured
in Btu per hour. The heat input multiplied by the efficiency equals
the heat output.
The correct furnace
or boiler size depends on the size of your home, its construction
and insulation, the way you use the house and the normal winter
temperatures in your area. A qualified gas heating contractor or
gas utility heating system specialist can estimate the heat loss of
your home by measuring the amount of wall, roof and floor space
exposed to the outside, and the amount of insulation you have.
Using a mathematical formula that includes the desired indoor
temperature and the local outdoor temperature ranges, the
contractor then recommends an appropriate size for your new
furnace.
Sizing estimates and
help with equipment selection should always be made by a qualified
contractor. A unit that is too large for your home can be less
efficient; a too small unit may decrease your comfort
level.
MAKING YOUR
SELECTION
While in the process
of comparing the various models of gas heating equipment, be sure
to use this handy checklist.
- Compare
the equipment for the best value.
- Check
the reputation and references of the
contractors.
- Get a
complete written contract, including all
provisions.
- Read the
contract thoroughly and understand it before
signing.
- Register
the warranty with the manufacturer, if
required.
- Keep a
copy of the contract, warranty and pertinent receipts in your home
file.
- Make
sure you are given an owner's manual for the unit
installed.
- Remember- Never store or use flammable liquids near any
appliance.
- Follow
all manufacturer's warnings and
instructions.
A.G.A. DESIGN
CERTIFICATION
When shopping for
your new gas heating system, always be sure the models you are
considering are Design Certified by the American Gas Association
(in the United States), Canadian Gas Association (in Canada) or
another nationally recognized laboratory. In 1993, the American Gas
Association and Canadian Gas Association formed a joint venture
called "International Approval Services" as a means of helping to
ensure that the design of gas appliances sold in these two
countries meet appropriate national standards.
SPECIAL TIPS
TO HELP YOU SAVE MONEY
WEATHERIZE TO
ECONOMIZE!
Make sure your home
is weatherized to present-day standards. Here are some steps you
can take to get the most from your heating dollars:
1. Caulk around
window and door frames to prevent the escape of warm air from your
home.
2. Weatherstrip doors and windows for a substantial contribution to
energy savings and a reduction of cold drafts.
3. Repair any cracks in the chimney or foundation of your home.
4. Install adequate ceiling insulation; heat rises and can easily
be lost through the roof.
5. Install insulation in exterior walls wherever possible.
6. Close doors to all unheated areas such as the attic, garage or
basement. Be sure all the doors fit tightly.
7. Check duct work for air leaks. Cracks or holes should be sealed
with duct tape.
8. Install storm windows and storm doors, and be sure to keep them
closed tightly.
9. Install a thermostat that automatically sets itself back at
night.
There are many other
energy efficiency measures you can take to save energy, save money
and increase comfort. Be sure to contact your local gas utility for
suggestions.
PROPER
MAINTENANCE
Now you should know
everything there is needed to select a gas furnace. However, you
also need to know how to maintain your furnace. You may ask, "How
can I keep my furnace operating efficiently and safely throughout
its lifetime?"
Heating specialists
recommend that your heating system be inspected each year. The
ideal time is before the beginning of the heating season. Call your
installing contractor, the manufacturer's local representative
listed in your Yellow Pages or your local gas company.
Here is a handy list
of tune-up checkpoints:
- Conduct
a visual inspection of the furnace vent
system.
- Clean or
replace the air filter, as required.
- Oil
motors that require it.
- Inspect
all chimney and flue connections and elbows to make sure they are
firmly fitted. Make sure there are no cracks or openings around the
flue pipe going into the chimney. If you find heavy rust,
particularly on the bottom of the pipe or around joints, there may
be excessive condensation inside the flue. This can be caused by an
improperly adjusted burner. Have the burner adjusted annually by an
expert. Check your chimney to make sure there are no interior
obstructions like leaves, bird nests and fallen bricks from
structural damage. They can interfere with the
draft.
- Oil the
blower motor and fan and inspect the blower belts for wear. Replace
them if they appear to be cracked or frayed. A broken fan belt in
the middle of a cold winter night can be a "chilling
experience."
- Clean
the pilots and burner chamber.
- Remove
dust and lint from furnace, vents and registers or baseboard
heaters.
- Clean
and adjust thermostats.

FOR YOUR
INFORMATION! IMPORTANT FACTS TO KNOW IF YOU ARE PLANNING TO
BUY OR SELL YOUR HOME.
ENERGY
EFFICIENT MORTGAGES
Did you know that you
can factor energy efficiency into the mortgage process? Doing so
can make home prices more affordable for lower-income
consumers.
This is done through
the Energy Efficient Mortgage (EEM). It allows a buyer to live in a
house more cheaply or buy a house for which they would otherwise be
unable to qualify.
How does the Energy
Efficient Mortgage work?
It
can allow for energy upgrades for existing homes.
The per month energy
savings from energy upgrades will usually be greater than the per
month investment required when the cost of upgrades are added to
the mortgage.
For example: Every
$1,000 worth of energy improvements added to a 10-percent, 30-year
loan requires an investment of 29 cents per day vs. a savings that
can exceed 49 cents per day.
It
can liberalize the underwriting tools for purchasing
houses.
In most cases,
lenders approve loans only if 28 percent or less of the borrower's
monthly gross income is needed for principal and interest on the
loan, plus taxes and insurance on the property. On an
energy-efficient home, lenders can stretch the debt-to-income
ratio, allowing as much as 32-percent of their gross income to go
toward these items. They do so by including the energy savings.
These liberalized ratios can allow a borrower to take out a larger
loan (roughly 12-percent larger) and purchase a larger home or
qualify for a first home, when under normal ratios they would
not.
For example: With a
"stretched" debt-to-income ratio, the adjusted income needed to
purchase a $75,500 home would be $21,375 rather than
$27,381.
WHO SUPPORTS
THE ENERGY EFFICIENT MORTGAGE?
The VA, FHA, GMAC
Mortgage Corp., Fannie Mae, and Freddie Mac are the primary lending
agencies that offer the energy efficient mortgage. You can obtain
additional information about Energy Efficient Mortgages from your
local mortgage lender, home builder or real estate
agent.
TABLE NO. 3 CONSUMER'S WORK SHEET
Use Chart 1 to figure
out the total cost of the furnace over its lifetime. The examples
shown assume the cost of gas to be 65 cents per therm. (Your
heating dealer can give you the estimated operating costs for the
different models you are considering.)
Chart 1 - Total Cost
Calculation
| Mode Name
(AFUE) |
Estimated
Yearly Operating Costs |
|
Average
Lifetime of Furnace |
|
Purchase Price
(includes installation) |
|
Total
Cost |
| Model A
High-Efficiency (94%) |
$282 |
X |
20 |
+ |
$3,000 |
= |
$8,640 |
| Model
B-Conventional (78%) |
$446 |
X |
20 |
+ |
$2,000 |
= |
$10,920 |
For additional
information, all public libraries have copies of the Consumer's
Directory of Certified Efficiency Ratings for Residential Heating
and Water Heating Equipment. This directory is published in April
and October of each year by the Gas Appliance Manufacturers
Association. Included in this directory is information on how to
estimate the annual heating requirements and how to compare the
cost of operation of different models.