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33 Cards in this Set
- Front
- Back
Main cause of incomplete combustion? |
Lack of oxygen |
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3 kinds of drafts for a gas furnace? |
Natural, induced draft, forced draft |
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What is backdrafting and what causes it? |
Occurs becuase furnace is getting insufficient air |
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What does a thermocouple do? |
Senses heat from a pilot flame |
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What is scorching? |
Plugged up heat exchanger resulting in a flame rollout |
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What should the setting on your thermostat anticipator match up with? |
The amperage of your gas valve |
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How much more pressure loss do you get from flex duct compared with smooth duct? |
3X the pressure loss |
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What are the two types of blower motors? |
Direct drive and belt drive |
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What makes a high efficiency furnace more efficient? |
Longer heat exchanger |
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What accessory do you need with a high efficiency furnace? |
Need a condensate pump or a drain as the furnace creates lots of moisture |
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What requirements must you keep in mind when venting a high efficiency furnace? |
1/4 per foot slope back to the appliance Support every 3 feet |
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For sidewall vent locations what are some key numbers to remember? |
3 to 6’ from a gas regulator 7’ above a walkway 1’ above grade 4’ below a soffit |
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1 gallon of fuel oil is equal to how many btu’s? |
140000 |
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1 cu ft of natural gas is equal to how many btu’s? |
1000 |
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Best location in house for a thermostat? |
Hallway, central in house, near your return |
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What are the two ratings of fire dancers and when would you use them? |
11/2 and 3 hr ratings Only use 3 hr when the partition has over a 3 hr rating |
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What is the length of duct you need before a breakaway joint? |
6” |
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For a fire damper sleeve how do you determine the gauge of metal you would use? |
Use same gauge as the duct it is connecting too |
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What are the 3 types of fire dampers? |
Type A - blades in airstream Type b - blades outside airstream(with hat section) Type c - circle types |
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What are the two damper types and what one is best for airflow? |
Parallel blade and opposed blade Opposed blade is better for airflow |
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What are spring loaded and gravity dampers also known as? |
Dynamic and static |
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Describe an hrv? |
Back (Definition) |
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What is safing? |
Blocking off a free area (usually with metal) where air could escape and go around a coil or something |
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What is the cause of acid rain? |
Carbon dioxide and water. Eg carbon coming out of a chimney |
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What would determine the type of venting you needed for your appliance? |
The btu’s of the appliance Aka how much heat is being exhausted out |
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A vent, be vent and c vent clearances |
A vent - 1” to combustibles - stainless steel B vent - 2” to combustibles - galvanized exterior and aluminium interior C vent - 6” to combustibles - galvanized
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What are the 3 main reasons to clean the air? |
Protect building and system, people Prevents contamination in industrial processes |
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Group 1 filters |
Viscous impingement filters Cardboard frame throw away filters commonly used in residential furnaces |
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Group 2 filters |
Removes particles 5-10 microns and up Pleated filters |
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Group 3 filters |
Can filter 99% of the particles down to 0.3 microns Some are electrostatically charged Lots of surface area — often bag filters |
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Group 4 filters |
HEPA filters Designed for low velocity Used for clean rooms and hospitals |
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Used to remove smells from the air? |
Carbon filters or Charcoal filters |
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There are two general ways of cleaning contaminants from the air |
Increasing the ventilation air Conditioning the air |