Residential Energy Audit - Chapter 6

Room heaters deliver all their heat  into ______ area. Central heaters convert fossil fuel or electricity to heat in a central location and use ducts or pipes to distribute the heat.

Some oxygen goes through combustion without reacting. The percentage of oxygen in _______ gases informs us about the fuel- air mixture.

6Open-combustion & closed-combustion describe whether the  or not the combustion chamber, heat exchanger, flues and chimney are open to the ______________ air.

__ ______ is preferred for gas appliance chimney, vent connector for 80+ gas furnaces as well as the chimney liner whenever there is space inside a masonry chimney.

Correct sizing of a furnace or boiler is a very important measure to reduce cycle losses.

• True

• False

Thermocouple and the photocell are common safeguards. They prevent Oil, natiral gas or propane from accumulating in the combustion chamber. Name one more safegueard used in combustion heating.

Name three common causes for cracked heat exchangers.

With a flame retention head oil berner (FRHOB) flue temperatures should never fall below 350 deg F because __________________

• Efficiency will decrease

• Flue gases could condense and cause corrosion.

What is the main purpose of vent dampers?

• Vent dampers prevent overheating and will shut down the burners if temperature over 575 deg F is detected

• Vent dampers reduces heat loss by closing off the chimney during times when the furnes or boiler is not in operation.

Unvented gas room heaters can deplete oxygen and produce unsafe quantities of CO, water vapor and oxides on nitrogen.

• True

• False

Intermittent ignition device (IIDs) can safe  3% to 5% of a furnace or boiler's fuel.

• True

• False

Combustion-air vents located high on the walls can cause a stack effect that will depressurize the mechanical room by way of stack effect.

• True

• False

Dirt & scale on the burner can cause incomplete combustion.

• True

• False

In oil & gas heaters burners mix and burn feul in combustion chambers.

• True

• False

Room heaters have no distribution losses.

• True

• False

Insulated double and triple wall chimneys can not be used as vertical chimneys for oil and solid fuel appliances.

• True

• False

Distribution losses can be reclaimed in cases where the distribution system run trhough the heated space.

• True

• False

When conducting a SSE test, which of the following results would desireable?

• CO2 readings between 3% - 13%

• Higher O2 Readings

Rooms may be hard to heat because of inadequate supply ducts or registers. Adding another supply duct and register is one option. Increasing the size of the existing duct and register is another.

• True

• False

Steam boilers have an air space at their water vessel's top, called teh steam dome,  where steam forms.

• True

• False

Match the following statement with one of the options below: A gas furnace rated AFUE 60+ and SSE 70+ will have these characteristics:

• Category 1 chimney, draft diverter, no draft fan, standing pilot, non-condensing, indoor combustion and dilution air.

• Category 1 chimney, no draft diverter, draft fan, electronic ignition, indoor combustion air, no dilution air

• Category IV chimney, no draft diverter, draft fan, low-temperature plastic venting, positive draft, electronic ignition, condensing heat exchanger, outdoor combustion air is strongly recommended.

Some wood stoves use catalytic converters that burn most of the unburned hydrocarbons from the fire.

• True

• False

A correctly sized heating system should:

• Heat your home to your desired temperature within an hour.

• Heat your home to your desired temperature within half an hour.

• Heat your home at roughly the same rate it is being lost.

Which of the quantities most accurately represent North America heating fuel usage the best?

• Oil 50%, other 5% electricity 15%, Natural gas 30%

• Oil 5%, other 50% electricity 15%, Natural gas 30%

• Oil 9%, other 9% electricity 29%, Natural gas 53%

• Oil 9%, other 9% electricity 53%, Natural gas 29%

The ____________ surrounding the the combustion chamber, transfers heat from the flames and combustion gases to the heating fluid - air, water or steam.

• Air

• Heat exchanger

• Insulation

Unreacted oxygen and unreacted nitrogen absorb heat from the combustion and carry it up the chimney.

• True

• False

In a open combustion heater, strong downdrafts may interfere with the burner or extinguish the pilot

• True

• False

Power burners use a blower to  to move combustion gases through the combustion chamber,

• True

• False

SSE is the percentage of heat captured by the heating fluids - air, water & steam.

• True

• False

Chimney draft in atmospheric-draft appliances should be negative ________ pascals depending on the outdoor temperature.

• 1 to 5

• 5 to 7

• 5 to 10

SSE is a good measurement of a heaters potential for improvement, or cost effectiveness of replacement. 

• True

• False

During a SSE test combustion gases are sampled _______________________

• Before they leave the heat exchanger.

• Before they are diluted by the dilution device

• After they are diluted by the dilution device.

In a steam heated system, why is fiberglass proper insulation type and not foam?

• Fiberglass is more cost effective.

• Foam has poor insulation characteristics.

• Fiberglass is resistant to the high temperatures of steam pipes.

Cast iron sectional boilers, copper water tube boiler and steel fire tube boilers are the three most common boiler types in single-family and multi-family buildings.

• True

• False

Combustion is slow oxidation; oxygen combines with the carbon  and hydrogen , splitting the hydrocarbon molecules

• True

• False

Draft diverters are designed to prevent excessive updrafts and increase downdrafts.

• True

• False

Name the mechanism in open combustion oil heaters that adjust dilution air to maintain a consistent chimney draft.

• Barometric draft control

• Temperature draft control

• Infrared draft control

Type-B vent is widely used as gas =appliance chimney.

• True

• False

Plastic pressurized condensing vents can only run vertically and not horizontally from the condensing appliance.

• True

• False

Fuel burning efficiency counts

• Chimney losses.

• Losses from incomplete combustion.

• Distribution losses.

Which are the preferred dilution device today?

• Draft diverter

• Barometric draft control

Off cycle losses is more important with boilers than furnaces because ___________

• Furnaces are AFUE certified

• Boilers have a heavier heat exchanger and heating fluid.

• Boilers lack behind in burner technology.

How can carbon monoxide, nitrous oxide, water vapor and sulfur dioxide produced by combustion heating escape into our living spaces?

• Cracked heat exchanger

• Back drafting

• Spillage

Cast iron sectional boilers, copper water tube boiler and steel fire tube boilers are used for hot-water and steam heating systems.

• True

• False

Safe use of unventilated gas room heaters do not require one or more wide-open windows.

• True

• False

Closing off registers in unused rooms often reduces airflow through the air handler and ducts, thereby reducung the system efficiency.

• True

• False

Efficiency =

• Input/output

• Output/input

• Input*output

Generating electricity from coal or oil wastes about ___% of the fuel's potential energy.

• 12

• 25

• 50

• 70