Heating System Flashcards
Heating system is required in almost every house, the sister should be capable of maintaining…
68° in every habitable place
What three ways is heat transferred?
Conduction, conviction, radiation,
Hot liquids and gases are lighter, more buoyant, and at a lower pressure compared to the surrounding material. What are two phenomenon related to this?
Stack effect and back drafting
Conduction occurs when…
Heat moves through solid it matter
Convection occurs win…
He moves by circulation of a gas or liquid
Radiation occurs win…
Molecules gain heat by absorbing electromagnetic energy in the infrared part of the spectrum
The presence of soot in and around a combustion chamber or vent for gas appliance me indicate what…
A significant combustion problem.
The term net free area is used to describe combustion air openings. Net free area means…
The opening area minus the space occupied by screens, louvers, or other obstructions.
Gas Combustion air from inside the house may be drawn from the same room where appliances are located. The “standard” method requires at least… of combustion air
50 ft.³ of volume in the room for every 1000 BTU input of the appliances in the room
Gas Combustion air may also be drawn from other adjacent rooms on the same story through openings between the rooms and the room where the appliances are located. What openings should there be…
Two openings, one within 12 inches from the floor and the other within 12 inches from the ceiling
Gas Combustion air may be drawn from other adjacent rooms through openings. What is the minimum size opening?
One square inch of net free opening area for every 1000 BTU input of the appliances in the room room
Gas Combustion air from the outside of the house may be provided by one or two openings. What is the minimum the free opening area? For each
1 permanent opening requires at least one square inch for every 3000 BTU
2 openings require at least one square inch for every 2000 BTU - Openings must be within 12 inches of the floor and ceiling
Combustion air ducts, should usually be constructed using…
At least 28 gauge galvanized steel
What are prohibited location for gas appliance and oil appliance….
Bedroom, bathroom, closet, or in a space that opens only into the spaces.
Unless the appliance obtains all combustion air from outside
What is make up air.
Make up air replaces air removed from the house by appliances.
For example close drawers, kitchen exhaust hood, and bathroom exhaust fans
Exhaust appliances compete for air with fuel burning appliances. This competition can cause…
Incomplete combustion and back drafting
A heat source capable of maintaining at least 68° should serve every habitable space in a house.
The temperature measurement is made where…
3 feet above the floor and 2 feet from an exterior wall
Inspector should operate the heating system using normal operating controls. True or false
True
Visual inspection of the heating system involves opening access panels that are provided for homeowner inspection and maintenance, and that are not sealed in place. True or false
True
Heating systems should not be tested when the outside temperature is above…
80 to 90°
Gas burning appliances are classified as category I through IV appliances. What are some characteristics of a category I appliance…
Vent gas is hot, 300 Degrees
Vents include the type B vents, masonry chimney’s, and single wall that’s
What are some characteristics of a category III gas appliance?
Vent gas is hot or hotter than a category I vent gas
These gases are under positive pressure
Tankless demand water heater is in this category
Category IV gas appliances have what characteristics?
Vent gas is rather cool around 140°
Vent gas is so cool it must be exhausted under positive pressure
Condensation is an issue
The heat exchanger is the heart of the furnace. True or false
True
Fans in newer and more expensive gas furnaces have multiple speeds. Is it a (low, medium or high) efficiency HVAC system
Medium
Why is an heat exchanger cracks a major safety issue?
Cracks or damage to the heat exchanger walls can allow combustion gases to enter the airflow and get circulated in the house
Heat exchangers in a new furnaces have many curves that increase the heat exchanger surface area. What are they sometimes called?
Serpentine
The serpentine structure of newer heat exchangers require…
A draft inducer fan is required to pull the combustion gas is through the curves
Are flexible gas connectors permitted to enter the cabinets of a gas furnace?
No
What are they silver colored buttons near the burners of a gas furnace?
Flame rollout sensor
What sensor shuts off the furnace if it detects excess heat?
High limit or fan limit sensor
What safety switch stops the ignition sequence if the draft inducer is malfunctioning?
Draft sensor.
which is connected by tube to the draft inducer fan
Home inspectors should observe the burners and gas flame, if possible.
A properly burning gas flame is…
Blue, sometimes with a slight yellow tip
Home inspector should report a gas flame if…
It is yellow or orange colored.
Indicates problems such as an improperly adjusted burner or gas valve, or an inadequate combustion air
What is a possible indication of a cracked heat exchanger?
Hey flickering or distorted flame
Vented room heater, the shut off the maybe located in another room or space if the valve is permanently labeled, readily accessible, and serves no other appliance. True false
True
The chimney damper for a vented gas log when installed in a factory built chimney or masonry chimney should be…
Permanently opened
This is accomplished with a damper stop
A type B vent may be used in most vent and vent connector applications. Use of single wall pipes is limited to…
Mostly to vent connectors in warm climates.
Oil burning appliances use what type vent ?
Type L
Type B vent should terminate at least _____ from a vertical sidewall or gravity air intake openings or at least _____ above any obstruction within _____.
8 ft - 2ft - 10ft
Keyword gravity air intake
All gas vents should terminate at least _____ feet horizontally or _____ feet vertically above a mechanical air intake opening
10 ft - 3 ft
Keyword mechanical
The flame from a modern oil burner should be…
White, possibly with a little yellow
What are the vent types for gas and oil, respectively?
Gas - B vent
Oil - L vent
Gas and oil furnace vents should be how many feet above the draft hood or flu collar?
5 ft.
Type L vent should terminate _____ above any obstruction within _____ of the vent.
Greater than or equal to 2 feet
Greater than or equal to 10 feet
What is the 3-2-10 rule?
That must be 2 feet above any part of the house within 10 feet.
And/or 3 ft above any mechanical air intake
Should be home inspector report the presence of portable heaters, especially if the heater provides the only heat source for a room?
Yes
What is the device that controls when a hot water boiler activates?
Aquastat
What items should home inspectors compare on a boiler inspection?
They should compare the tag on the pressure relief valve to the boiler reading plate.
The pressure readings should be the same.
The temperature or BTU rating should be greater on the relief valve than the boiler.
What should all steam heating systems with wet returns have?
And equalizer pipe and a Hartford Loop.
Keyword steam