HVAC, Plumbing, Valves Flashcards
What is HVAC?
Heating, Ventilation and Air Conditioning
Purpose of HVAC?
Control temperature within space, control of moisture, filtration of air borne particles, movement of air, supply fresh air from outside
What is heating?
To increase the temperature by adding thermal energy
What is cooling?
To decrease the temperature by removing the thermal energy
What is humidifying?
The process of increasing the relative humidity by addition of water vapor or steam
What is dehumidifying?
The process of removing the water vapor or humidity
What is cleaning?
The process of removing dust, pollens, smoke, and contaminants
What is ventilating?
The process of adding external air to freshen up the air and maintaining gas ratio
What is air movement?
To control the movement of supplied air so that the inhabitants of the space do not feel discomfort
What is sensible heat?
Describes how hot something feels (Degrees C, F, K)
What is latent heat?
The quantity of heat energy in a substance
What does BTU stand for?
British Thermal Units
What is a thermostat?
Brain of the system, senses heat/cold, keeps system at desired temperature, displays current temperature
What does a blower motor do?
Circulates air in the system
What are ducts?
Pathways for heated or cooled air to travel
What is supply air?
Vents that supply heated or cool air to a room
What is return air?
Takes air from a room and returns it back to the heating/cooling system
What is a heat exchanger?
A device that transfers heat between two or more fluids
What is refrigerant?
A chemical used in a cooling mechanism
What does an evaporator coil do?
Allow compressed cooling chemicals to evaporate from liquid to gas while absorbing latent heat in the process
What does a condenser do?
Turns the chemicals from a gas to a liquid by cooling it (removing latent heat)
What is a compressor?
A pump that causes the refrigerant to flow through the system
What are line sets?
Two semi-flexible copper pipes to connect the outdoor air conditioner or heat pump to the indoor evaporator coil
What is plumbing?
The system of pipes, tanks, fittings, and other apparatus required for the water supply, heating, and sanitation in a building
In the midwest, how deep do water lines need to run?
3 feet
Supply anchors need to be every how many feet?
6 feet
What is a stack?
The vertical drain pipe that other drain pipes feed into
What PSI does clean water enter a house?
50-60
What are some rules for a good system?
- shut off valves for every fixture and appliance
- vents
What is a rough-in?
Where the basic lines are laid without making the final connections
What is pipework?
Any system of pipes or tubes
What are PEX (Cross Linked Polyethylene) Pipes?
- one of the newest and most popular pipes to the plumbing market
- is rigid enough to withstand pressures of water supply but flexible enough to weave throughout the walls, ceilings, basements and crawlspaces
What are PVC (Polyvinyl Chloride) Pipes?
- a drain or vent line type of plumbing pipe
- lighter and easier to work with than galvanized steel pipe
- glues together with solvents
- easy to install but requires more than a hacksaw and a miter box to cut
What are Rigid Copper Pipes?
- often used for water supply lines within the home
- easily cut with hacksaw or with a special copper tube cutter
- it requires a practiced hand to solder copper pipe together
- great for water supply because it does not come with any health risks
What are ABS (Acrylonitrile Butadiene Styrene) Pipes?
- mainly used as a vent and drain line
- looks like PVC but is black and slightly softer
What are Flexible Copper Pipes?
- used for final runs to water heaters, refrigerators, and some sinks
- only used for short runs and can be cut with a hacksaw
- bent to fit around corners
What are Galvanized Steel Pipes?
- still around but only used for gas supply
- was used for decades for drainage, water supply and gas supply
What are Cast Iron Pipes?
- was often used used for sewer and other drainage purposes
- found in many homes today
- viable until the point it rusts completely through
- very heavy and difficult to cut
What is corrosion?
The deterioration of metal on nonmetal surfaces
What is are Braided Stainless Steel Flexes?
- used for hooking up a faucet or other fixtures to water supply
- has multiple options of fitting to choose from
- around 125 PSI maximum pressure rating
- constructed with durable braided stainless steel outer sheathing with tough nylon reinforced vinyl tubing inside
What is a valve in plumbing?
A type of fitting that allows regulation, control, and direction of fluids passing through a pipe
What are valves commonly used for?
Direct flow, shut off water access, prevent back-flow, and adjust water pressure within a system
What is a ball valve?
- control water flow by using a rotational ball located in the center of the valve
- turning handle 1/4 is enough to seal off the flow of fluid
- most commonly used as shut off valve
What is a butterfly valve?
- also used as shut-off valve
- to isolate and regulate flow
- constant exposure to rushing water will erode the disc element and weaken the watertight seal
- controlled by a 1/4 turn of a handle
What is a check valve?
- ensure that water is only permitted to flow in one direction
- are for back-flow prevention
What is a needle valve?
- allow for precise control of water flow by the raising and lowering of a threaded, conical spindle
- used for isolation, regulation, and throttle of liquids and gases
- offer flow control with precision
- capable of withstanding very high pressures
- ideal for applications where fluid needs to be shut-off gradually, or a very low flow rate is desired
- tip seals perfectly within a valve seat at the very bottom
What are some different types of cooling systems?
- Central Air Conditioners and Heat Pumps
- Room Air Conditioners
- Evaporative Coolers
- Ductless Mini-Split Air Conditioners
