Hot Water Tanks Flashcards
What are the 4 different type of hot water tanks?
Gas
Electric
Indirect
Instantaneous
Gas HWT Part 1:
- How long to heat up 40 Gallons? (approximate in minutes)
- Describe how it works (From ignition to leaving building)
- Working pressure is up to ____ psi, built to withstand _____ psi
- What are the most common sizes (in US Gal)
- 40 minutes
- Flame is ignited on burner, Heat rises through meatal chimney, baffles inside chimney slow hot air to make it more effective. Gasses then leave building through a venting system
- Working is 150 psi and withstands 300 psi
- 30, 40, and 50 US Gal
Gas HWT Part 2
what are the Pros and Cons:
(1 Pro, 3 Cons)
Pro: Very Good recovery time
Con: Need Flu/Vent, Limited locations, and Loss of heat through flue
Instantaneous Heater (Tankless)
- What situations might you want to use this in?
- When does it start heating the water and how?
- What is the heat source?
- What is a downside to these heaters?
-Shortage of water or a small amount of space
- When a tap is opened a flow switch will activate a start heating hot water
- Uses propane or natural gas as a flame source
- Requires frequent maintenance
Electric HWT Part 1:
-Rated in what voltages?
- What are the 2 types of elements available and what type of heat transfer do they use?
- Which element is most often on in a 2 element style tanks?
- what type of union is needed if copper lines are in the house?
- What 2 components are used to prevent corrosion of the tank?
- 120V, 240V, and 208V
- Strap on elements use conduction and Immersion elements use convection
- the bottom one
- Dielectric unions
- A Inamal Tank liner and the Anode rod
Electric HWT Pros and Cons:
list 4 Pros and 1 Con
Pros:
- can be placed almost anywhere
- No Vent
- no Energy loss in heat transfer
- Quiet
Con:
- Has a slower recovery time
Indirect Fired HWT:
- what other system is used to heat the water
- What type of coil does the heat source go through in the domestic tanks?
- what device is in the tank that calls for it to be heated?
- what are the substances used in a exchange type and in a converter type
- Uses a seperit boiler system
- Usually copper or stainless
- An aquastate will detect when the tempeture of the HWT needs heat and will call for the Hot water/Steam of the boiler
- Exchange uses hot water to heat the water and a converter uses steam to heat the water
Problems:
- What has happened if there is a short circet of water?
- There is no continuity on the elements
- Dip tube has probably broken off
- Elements have broken/snaped
Components Part 1:
- Storage tank
- Pump (Required after how many m?)
- Setting dials (3 different tempitures warm normal and hot in C)
- Cold water inlet needs what?
- Hot Supply Doesn’t need what?
- Where the water is heated/stored
- Required after 30m
- Warm 50C, Normal 60C and Hot 70C
- A shut off valve
- A shut off valve
Components Part 2:
- Anode Rod is for? and made out of?
- Vacuum relief valve is used where and for what?
- Dip Tube is for
- To reduce corrosion, made out of Magnesium (less noble then steel tank)
- Used on the cold water supply and prevents back siphonage and is normally closed
- Bringing the cold water straight to the bottom of the tank
T and P Valves:
- Opens at what temperature? (C)
- Opens when line pressure is _______ than normal but before the _____ pressure
- Must be installed with in the top ____” of the tank
- Must drain to within ____” of the floor
Tags on T&P valves must include: ______ size, _____Rating and _____ Rating
- 99C
- Higher than normal but before max pressure
- 6”
- 12”
- Thread size, PSI Rating and BTU Rating
Mixing Valves:
- How doe they work
- what does this allow HWT to do and what disses does it prevent
- What temperature does this disses grow at Degrees C
- Cold and hot water are combined to create temperd water
- Allows HWT to stay at a higher temperature and prevents legionella
- 20-45 degrees C
- What are the 2 types of Multiple tank systems?
- Explain the way water goes through each of these systems
- What are the benefits to each system?
Series: First tank is the primary one used well the others act more as storage for the hot water, others will turn on as demand increases. a benefit is that if one tank isn’t working it isn’t a rush to replace it.
Parallel: no rush to replace tank if its damaged. the lines going in and coming out of the tanks must be equal till point of joining so as to prevent short circuiting.
