Hydronics Cooling, Antifreeze, and Other Flashcards
Antifreeze in Boiler Systems (Glycol) Part 1:
What are the advantages of adding Glycol? (List 3)
Antifreeze in Boiler Systems (Glycol)
Advantages:
- Glycol is added to a boiler system to prevent freezing of liquid
- Freeze up most often occurs in slab on grade applications
- When glycol is added boiler systems can be used for snow melting
Antifreeze in Boiler Systems (Glycol) Part 2:
What are the disadvantages of adding Glycol? (List 3)
Disadvantages:
- Glycol requires more heat energy then water
- Pumps are affected by the high viscosity of glycol
- Glycol expands more then water so an expansion tank must be 15% to 20% bigger
Antifreeze in Boiler Systems (Glycol) Part 3:
- what are 2 types of glycol?
- What % range can glycol be added as?
- Two types of glycol: Ethylene and Propylene
- Glycol inheriting systems can be a mixer of between 60% Glycol to 40% Water (60/40) to 30/70 depending on the need (30-60% Glycol)
Antifreeze in Boiler Systems (Glycol) Part 4:
Ethylene:
- Is it toxic?
- What must be added and why?
- What type of Backflow is mandatory?
Ethylene:
- Very toxic and corrosive
- Corrosion inhibitor must be added to prevent damage
- Backflow prevention is VERY serious so a RP would be used on this type of system
Antifreeze in Boiler Systems (Glycol) Part 5:
Propylene:
- Is it toxic?
- Better or worse heat transfer then ethylene?
Propylene:
- Food grade glycol and is non-toxic
- Has a slightly better heat transfer rate then Ethylene
In Floor Heating System part 1:
- What is another name for in floor?
- what are 2 applications?
- Max Length for pipe sizes in this system for 3/8” 1/2” and 3/4” (in feet)
In Floor Heating System:
- Also called “radiant panel heating systems”
- Used for: Home Heating, and snow melt applications
- Max Length for pipe sizes in this system:
⅜” ID = Max 250’
½” ID = Max 300’
¾” ID = Max 500’
In Floor Heating System part 2:
Manifolds:
- Are used for what purpose?
- Balancing valves are not required if the difference in length between the longest and shortest runs is less than _____%
Manifolds (Headers)
- Used to distribute heat to different “Zones” this Prevents the use of long circuits which may cause pressure drop or poor flow rates
- Balancing valves are not required if the difference in length between the longest and shortest runs is less than 10%
In Floor Heating System part 3:
Piping:
- Where should supply piping go first?
- Exterior piping c-c? other piping max c-c?
- what is required when supply or returning come from/to the concrete/slab
Types Of Piping Layouts :
- Piping should go to wear heat loss will be the greatest first Ex: Exterior wall, and windows
- exterior wall piping on 6” centers, Each pipe should be no more than 12” c-c
- A rigid 90° bend is required when supply or returning from the concrete/slab
In Floor Heating System part 4:
Types Of Piping Layouts :
Explain the pattern each layout takes and how many exterior wall each would have.
- Single Serpentine Layout:
- Double Serpentine Layout
-Triple Serpentine Layout
- Counterflow Pattern
Types Of Piping Layouts :
4 different layouts for piping:
- Single Serpentine Layout: For 1 exterior wall in a room
- Double Serpentine Layout: For 2 exterior walls
- Triple Serpentine Layout: For 3 exterior walls
- Counterflow Pattern: Interior room, with NO exterior wall
In Floor Heating System part 4:
Pressure test for tubing:
- what is the minimum psi test? and how long?
- Tested before or after concrete?
- Test on or off durn pour of concrete and why?
Pressure test for tubing:
- Must be tested and a minimum of 60 psi for 1 hour
- Tested before the pouring of the concrete
- Test left on durn pouring to protect piping
Cooling Part 1:
- 1 ton of refrigerant = _______ BTUs
Cooling:
Refrigeration is measured in tonnage (tons)
1 ton of refrigerant = 12,000 BTUs
Cooling Part 2:
Chillers:
- what’s it used for?
what does each sections of a chiller do?
- Compressor
- Expansion valve
- Condenser
- Evaporator
Chillers:
- Used to chill a liquid
4 sections to a chiller
- Compressor: Moves Refrigerant around in chiller
- Expansion Valve:
- Condenser: wear the condensing loop exchanges its low temperature with the refrigerant. The condenser loop then goes off to the cooling tower to be recooled (like a heat exchanger)
- Evaporator: Chilled water loop passes by cooled refrigerant then goes off to cooling units in the building
Cooling Part 3:
Cooling Tower:
- how does it work?
Cooling Tower:
- Cooling towers extract heat waste from water in an air conditioning systems By having the water trickle over panels exposing it to the atmosphere, Evaporation of some of the water and air flow can cool the water down significantly, Water is then captured in a reservoir below and then circulated back to the chiller
Cooling Part 4:
Pump:
- what does it do?
- What is the most common pump?
Piping:
- What is a rupture disc?
Pump:
- Moves Liquid (water or Glycol) to and from the chiller to either a cooling tower or to inside the building to air handling coils/units
- Most commonly used pump is a centrifugal pump
Piping:
- Very similar to that of a hydronic system
One difference is that a chiller trim will have a “Rupture Disc”
- A Rupture Disc will brake if the system is over pressurized, which empties the content of the piping into a large reservoir
Cooling Part 5:
Air Handling Unit:
- how does it work/ what is it used for?
- Can they also be used for warm air?
Air Handling Unit:
- Air passes through the units and is chilled by the cold water, The cool air is then used to condition the building, The water then goes back to the chiller to be recooled
- Air Handling units can also deliver warm air in the heating season
