Cold house.

I just returned from a customers home that was concerned with high heating bills and the house was not very warm (62-64* F).  Before arriving I assumed the system was just not very efficient and undersized.  What I found was a very poorly insulated ductwork system (that was in the attic) and the attic overall was poorly insulated as well. 

My initial recomendation to these folks is to have a Blower Door/ Home Assessment test done to their home to determine exactly how "leaky" their home actually is and to pinpoint the air leaks.  Once this is complete now we can start sealing and insulating the duductwork, sealing the recessed lights, and properly insulate the entire attic.  Also address any leaky windows, doors, or outlets.

After all the insulating and sealing is complete a post test should be done to see how lees leaky the home is.

As I was driving away I realized I had not quoted any prices on the replacement of equipment.  Prior to receiving proper training on building science, I probably would have quoted a new more efficient furnace and not taken as much time looking at the attic and understanding what was going on with the home.  It became very apparent to me the need of being BPI certified and understanding the entire home as a system.

Central Gas Furnace Terms & Definitions

Annual Fuel Utilization Efficiency (AFUE): The Annual Fuel Utilization Efficiency (AFUE) rating, indicates
how well a furnace converts energy into usable heat. The rating is expressed as a percentage of the annual output of heat (output rating in Btus -- British thermal units, a measure of energy) to the annual energy input to the furnace (input rating in Btus).

Ratings can be categorized in the following way:

• Low Efficiency: AFUEs below 71 percent.
• Mid-Efficiency: AFUEs between 71 and 83 percent.
• High Efficiency: AFUEs of 90 percent and above.

Ratings between 84 and 89 percent are not common. Acidic condensate, harmful to the furnace, forms at
these percentages. Public Law No. 100-12, passed in1987, requires that all gas furnaces manufactured after January 1, 1992, have aminimum AFUE of 78 percent.

Atmospheric Vent Combustion: If a chimney is available, furnaces with this system are the least
expensive to install. Atmospheric vent furnaces have AFUEs of 60-65 percent when equipped with
standing pilots, and AFUEs of 63-70 percent when equipped with electronic ignition systems.With special
vent dampers, atmospheric vent units can achieve AFUEs of 78-80 percent.

Condensing (or Recuperative Units): These units are super efficient with some designs reaching AFUEs
of up to 97 percent. Unlike conventional forced air furnaces, condensing units capture most of the water
vapor and heat contained in hot flue gases that would normally escape up the chimney. The escaping gases then pass through a second heat exchanger and condensate is expelled. The heat exchangers are made of corrosion resistant stainless steel, and many have lifetime warranties. Exhaust is cooler than that of conventional furnaces and can be vented with PVC piping.

Downflow or Counterflow Furnace: These units have a blower at the top to draw air into the furnace.
Heated air is blown out at the bottom. This type of furnace isused to supply floor duct systems.
Electronic Ignition: An electronic ignition eliminates the need for an energy-wasting standing pilot. Fuel is used only when needed. The pilot is ignited with an electric spark.

Heat Exchanger: The heat exchanger is a metal chamber in the furnace that houses a gas burner. The
flame produced by the burner heats the chamber. When the outside of the chamber becomes hot, the air
surrounding it is warmed and used to heat the house. Improved designs enhance efficiency and provide
quieter operation.

Horizontal Flow Furnace: Air travels horizontally from one side of the heater, across the heat exchanger,
and hot air is blown out the other side. This type of furnace is installed in areas with limited head room, such as attics or crawl spaces. They can also be installed below floors or suspended below ceilings.
Nonweatherproof: These units are designed to be installed indoors.

Power Combustion: In this system, combustion is produced by a blower. The blower pushes the combustion gases through the vent, and regulates the amount of combustion air. Power combustion
furnaces do not require a draft hood. This reduces off-cycle losses and improves efficiency. Many power
combustion furnaces operate at 78-80 percent AFUE. When equipped with an additional heat exchanger,
they can operate at AFUEs of 90-96 percent.

Pulse Combustion: (These models are listed under condensing furnaces.) Pulse combustion is produced
by self-perpetuated "pulses." This unique system mixes air and fuel in a sealed combustion chamber. A
spark ignites the mixture, and the resulting increase in pressure closes the gas/air inlet valve. The
combustion products are forced through an exhaust pipe and the pressure in the combustion chamber
drops, re-opening the inlet valve. The next combustion cycle is ignited by the heat remaining from the
previous cycle. This process repeats itself about 60 times per second. Furnaces with this combustion
system have AFUEs from 91-97 percent. Exhaust gases, at 100-200 degrees Fahrenheit, are cool enough
to vent through PVC piping.

Sealed Combustion: Sealed combustion systems draw in all the air used for combustion from the outside,
and exhaust gases are direct vented to the outside. Since cold outside air is not mixed with the warm indoor air during combustion, efficiency is enhanced. Furnaces with this type of combustion system have an AFUE range of 70-80 percent.

Upflow Furnace: These units have blowers at bottom that draw air into the furnace. Heated air is blown out at the top. These heaters can be installed in utility rooms, closets or basements.

Vent Damper: The vent damper is a "flapper" device installed in the flue. When the heat demand has been
met, the damper closes, trapping residual heat for circulation in the home. When heat is needed, the
damper opens before the burners are ignited to allow combustion fumes to escape. The damper remains
open only as long as the burners are on. Burners cannot ignite if the damper is closed.

Weatherproof: These units are designed to be installed outdoors.

Understanding Basic Combustion

Useful Information on Combustion Efficient Fuel Use
A Definition: Combustion is the rapid oxidation of a fuel resulting in the release of usable heat and the
production of a visible flame

The Combustion Equation:
Natural Gas With Air:

• CH4 + 2O2 + 8N2 ----------->
• CO2 + 2H2O + 8N2 + 1000 BTU Heat

Examples of Combustion
Perfect Combustion Provides:

• The hottest flame
• Minimum exhaust volume

Perfect Combustion
Characteristics:

• All fuel combusted
• Blue near burner tile
• Forms a yellow conical flame shape
• Produces the highest flame temperature
• Provides the minimum exhaust volume

Lean Combustion
Characteristics:

• Flue products oxidizing (Free O2)
• Pale blue color
• Forms a more conical flame
• All fuel combusted
• Flame temperature drops (Heating excess air)

Incomplete Combustion
Characteristics:

• Air starved or fuel rich
• Carbon Monoxide and H2 formed
• Reducing atmosphere
• Flame color is predominantly yellow color
• The flame is less defined
• Flame temperature drops

Optimum Energy Utilization Occurs When Perfect Combustion Ratios Are Maintained
When A Furnace Tune-Up Is Done Right The Technician will have taken time to:

• Verify proper mix and directed air/fuel supply
• Confirm that you have stable combustion
• Check to make sure that the system is venting all the by-products of the exhaust flue gases

A Definition of Combustion Terms
Excess Air Definition:

• Air remaining after the fuel has been combusted -or-
• Air supplied in addition to the quantity needed for stoichiometric combustion

Primary & Secondary Air:
Primary Air --

• Air mixed with the fuel prior to ignition

Secondary Air --

• Air supplied to the flame after it is ignited

Secondary Air Effects --

• Imprecise air/fuel ratio control
• Exhaust volume increases
• Fuel rate rises
• Less available heat

A New Furnace Can Reduce Heating Costs

Heating bills across the country are the highest they have ever been, with out any relief in sight.
Even if your older furnace runs, from an economic standpoint it would be wise to replace it. With
the proper furnace selection, your central air-conditioning bills can be lower too.
Compared with a 17-year-old furnace, a new furnace can save the typical family hundreds of
dollars per year. Based on the efficiency of your old furnace, probably 60% at best, a new
furnace can cut your utility bills by 40%. You can do the arithmetic to determine your annual
savings.

Not only will you have lower utility bills, but the comfort and quiet operation of a new system will
surprise you. The contractor should install a computerized thermostat with it. This thermostat,
coupled with the electronic controls in the new furnace, will maintain even room temperatures.
You can choose from two basic designs of furnaces: condensing and non-condensing. The
condensing models (this refers to the type of heat exchanger used) are the most efficient and
the best choice for most homeowners. The efficiencies of condensing models range from about
90% to over 95%.

These models are very efficient, and so little heat is lost in the flue gases that a chimney is not
needed. The gases are exhausted by a 2-inch-diameter plastic pipe through an outdoor wall.
With no need for a new chimney liner, a condensing furnace is often cheaper to install.
Some models also offer sealed combustion for better efficiency. The combustion air is drawn in
from outdoors through another plastic pipe instead of being drawn from inside your house. Being
sealed, there are fewer indoor drafts, less noise and less chance of hazardous back drafting.
For the ultimate in comfort and efficiency, but at a higher initial cost, is a two-stage heat output
furnace with a variable-speed blower. This type of blower is needed if you want the best central
air-conditioning.

In all but the coldest weather, the gas burners operate at a low heat level. This allows the
furnace to run more continuously with fewer uncomfortable on/off cycles. The blower also runs
slower and quieter at this low level. During very cold weather, it automatically switches to high
heat.

If your budget allows, also install a quality air cleaner. Since a two-stage unit runs more, the air
cleaner is more effective for allergy sufferers.

Central Air Conditioning Definitions

Air Conditioner: Assembly of equipment for the simultaneous control of air temperature, relative humidity, purity, and motion.

Air Cooled: Uses a fan to discharge heat from the condenser coil to the outdoors.

Air-Source: Air is being used as the heat source or heat sink for a heat pump.

BTU: British Thermal Unit. The amount of energy needed to change the temperature of one pound of water by one degree Fahrenheit. In practical terms, it represents a unit of measure of heat extracted from your home for cooling.

Central Air Conditioner System: System in which air is treated at a central location and carried to and
from the rooms by one or more fans and a system of ducts.

Compressor: The pump that moves the refrigerant from the indoor evaporator to the outdoor condenser
and back to the evaporator again. The compressor is often called "the heart of the system" because it
circulates the refrigerant through the loop.

Condenser Coil: A series or network of tubes filled with refrigerant, normally located outside the home, that removes heat from the hot, gaseous refrigerant so that the refrigerant becomes liquid again.
Cooling Capacity: A measure of the ability of a unit to remove heat from an enclosed space.

COP: Coefficient of Performance of a heat pump means the ratio of the rate of useful heat output delivered by the complete heat pump unit (exclusive of supplementary heating) to the corresponding rate of energy input, in consistent units and under operating conditions.

EER: Energy Efficiency Ratio means the ratio of the cooling capacity of the air conditioner in British Thermal Units per hour, to the total electrical input in watts under ARI-specified test conditions.

Evaporator Coil: A series or network of tubes filled with refrigerant located inside the home that take heat and moisture out of indoor air as liquid refrigerant evaporates.

Free Delivery: There are no ducts and the unit may be installed in the field without ducts if needed.

Ground-Source: The ground or soil below the frost line is being used as the heat source or heat sink for a
heat pump.

Ground Water-Source: Water from an underground well is being used as the heat source or heat sink for a
heat pump.

Heat Pump: An air conditioner capable of heating by refrigeration. It may or may not include a capability for cooling. Outside air or water is used as a heat source or heat sink, depending upon whether the system is heating or cooling.

Heating Capacity: A measure of the ability of a unit to add heat to an enclosed space.

HSPF: Heating Seasonal Performance Factor means the total heating output of a heat pump in British
Thermal Units during its normal usage period for heating divided by the total electrical energy input in watthours during the same period.

SEER: Seasonal Energy Efficiency Ratio means the total cooling output of a central air conditioner in British thermal units during its normal usage period for cooling divided by the total electrical energy input in watthours during the same period as determined using the ARI-specified test procedure. This rating is only for units with cooling capacity less than 65,000 Btu/hr. The higher the SEER, the more efficient the unit. The more efficient the unit, the lower the operating cost.

Single Package: A central air conditioner which combines both condenser and air handling capabilities in a single packaged unit.

Split System: A central air conditioner consisting of two or more major components. The system usually
consists of a compressor-containing unit and condenser, installed outside the building and a noncompressor -containing air handling unit installed within the building. This is the most common type of system installed in a home.

Ton: The unit of measurement for air conditioning system capacity. One ton of air conditioning removes
12,000 Btu's of heat energy per hour from a home. Central air conditioners are sized in tons. Residential
units usually range from 1 to 5 tons.

Water-Source: Water is being used as the heat source or heat sink for a heat pump. Sources of
underground water are wells and sources of surface water are lakes, large ponds, and rivers.
Year-Round: Air Conditioner which uses gas or oil for heating.

The Chapman Family Picnic

Earlier this month we had our annual Chapman Family Picnic.  Where all the white van boys bring their families, a side dish and we all have a fantastic time.  This year the fun exceeded the past years for several reasons: the weather was a beautiful 80 degrees,  Nathan brought a blow up waterslide for the kids and Chad (Shana's husband- and master griller) did the grilling.  I also realized this year how many chefs we have in our family- the food was amazing.

The Research Blog

As time changes, so does our site.

Soon, you'll start finding more helpful tips, hints, and help about your heating and cooling systems. In the mean time, if you have questions, don't hesitate to contact us.