private and confidential hot water temperature maintenance
TRANSCRIPT
Private and Confidential
Hot Water Temperature Maintenance
Private and Confidential Enter Date Here page 2
HWAT Simply Keeps Hot Water Hot
Water provided from Water Heater
Insulation
Pipe
Heat provided by HWAT heating cable
Heat lost through the insulation
Air at 70F
HWAT heating cable
Private and Confidential Enter Date Here page 3
Movement of Water in HWAT System
Water heater is set to the desired maintain temperature
HWAT maintains the hot water by replacing the heat lost through the thermal insulation
HWAT-Y2
70F Water moves through fixture.
Water in untraced section cools to ambient 70F
Heated water moves into pipes.
Hot water arrives at fixture.
Private and Confidential Enter Date Here page 4
HWAT or Recirculation?
HWAT Recirculation
Private and Confidential Enter Date Here page 5
WaterHeater
RecirculationPump
Return Piping
Balancing Valves
Typical Recirculation System
Private and Confidential Enter Date Here page 6
WaterHeater
HWATHeating Cable
Typical HWAT System
Private and Confidential Enter Date Here page 7
HWAT History
System developed by Raychem in 1976
Installed in more than 300,000 buildings
More than 2,500,000 feet of HWAT cable installed every year
More successful in Europe due to a greater focus on water and energy conservation which is only a recent trend in North America
Private and Confidential Enter Date Here page 8
Advantages of HWAT
Easy to design
Low installed and operating costs
No flow-balancing issues
Compatible with low-flow fixtures
Easy to provide instant hot water to the point of use
Water conservation/Reduced time to tap
Private and Confidential Enter Date Here page 9
Time to Tap – Water Conservation
Water in 10’ of ½” pipe = 0.1 gallons
Water in 40’ of ¾” pipe = 0.9 gallons
Water between fixture and recirculation loop = 1.0 gallons
If this fixture is used 5 times per day, the annual water waste would be 1,825 gallons per year!
Private and Confidential Enter Date Here page 10
Disadvantages of HWAT
Perceived as new technology
May not be economical for certain building configurations
“Me-Too” competitive systems fail to perform as expected on an HWAT design
Private and Confidential Enter Date Here page 11
Typical HWAT Building
Why is this a good HWAT application?
Private and Confidential Enter Date Here page 12
Typical HWAT Building
No horizontal return piping
No booster pumps or booster heaters
No balancing
Reduced supply piping
Private and Confidential Enter Date Here page 13
Typical HWAT Building
Private and Confidential Enter Date Here page 14
HWAT Performance Issues
Hot water heater continuesto maintain the water at 115F.
HWAT replaces heat lost throughthe insulation and keeps the water at 115F.
HWAT-G2
Ambient temperature Water moves through fixture.
Heated water moves into pipes.
Uninsulated or unpowered section of HWAT
115 HWAT maintainedwater arrives at fixture.
Ambient temperature Slug Arrives at fixture.
Sections without insulation or power
Private and Confidential Enter Date Here page 15
HWAT Performance Issues
Hot water heater continuesto maintain the water at 115F.
HWAT replaces heat lost throughthe insulation and keeps the water at 115F.
Cold water pulled into hot side through hot to cold connection
HWAT-G2
Ambient temperature Water moves through fixture.
Heated water moves into pipes.
Heated water mixes with by-pass water
115 HWAT maintainedwater arrives at fixture.By-pass waterArrives at fixture.
Cold to hot cross connection at fixture.
Cold to Hot water by-pass
Private and Confidential Enter Date Here page 16
Main Mixing Valves
Main mixing valves are usually flow dependent. There should be a low flow and a high flow valve. If there’s only one, be sure it can function in a low/no flow situation.
Mixing Valves
Private and Confidential Enter Date Here page 17
Typical Maintain Temperatures
Temperature Application
105°F Hospitals, Nursing Homes
115°F Schools, Prisons
125°F Hotels, Apartments, Offices
140°F Kitchens, Laundries
125°F Residential
Private and Confidential Enter Date Here page 18
HWAT Heating Cables
B2 - 105°F
G2 - 115°F
Y2 - 125°F
R2 - 140°F
Y2 or R2
R2
Private and Confidential Enter Date Here page 19
HWAT Selling Tools
Private and Confidential Enter Date Here page 20
HotCAP
Hot Water Cost Analysis Program
Introduced in March, 2004
Integrates HWAT-ECO
Updated material costs
Updated labor, electricity and fuel rates
Download from web
Private and Confidential Enter Date Here page 21
HWAT-ECO Electronic Controller
Flexible temperature control
Insulation schedule
Energy savings
9 pre-defined programs
Heat-up cycle
Alarm events
Water heater sensor
BMS interface
Master/slave function
Power correction factor
Private and Confidential Enter Date Here page 22
Flexible Temperature Control
Maintain Temp
HWAT-Y2 105°F – 125°F*
HWAT-R2 105°F – 140°F
*Depending on the ambient temperature and voltage
Private and Confidential Enter Date Here page 23
Fiberglass Insulation Schedule
Copper pipe size (in) IPS insulation size (in) Insulation thickness (in)
½ ¾ ½
¾ 1 1
1 1¼ 1
1¼ 1½ 1½
1½ 1½ 1½
2 2 2 2½ 2½ 2½
3 3 3
Insulation thickness matches pipe diameter for equal heat loss
Pipes 1¼” and smaller require oversized insulation to allow room for the heating cable
For pipes 3” and larger, 1/3 the thickness of insulation can be used with 2 runs of heating cable
Private and Confidential Enter Date Here page 24
HWAT-ECO Limits the Power Output
400 seconds duty cycle
“On” time depends on the desired maintain temperature
4 Modes: Off, Economy, Maintain & Heat-Up Cycle
OFF
ON
15% ON
400’’ 800’’ 1200’’ 1600’’0’’
Economy Temperature
sec.OFF
ON
55% ON
400’’ 800’’ 1200’’ 1600’’0’’
Maintain Temperature
sec.
Private and Confidential Enter Date Here page 25
9 Pre-defined Programs
Private and Confidential Enter Date Here page 26
Programming Options
(48) ½ hour time blocks
Additional energy savings during “Off” and “Economy”
Private and Confidential Enter Date Here page 27
Heat-Up Cycle and Cool Down
Raise the water temperature of stagnant pipes
Determine the amount of time required to reach a desired maintain temperature
Program the number of hours required
Allow time to cool down before hot water usage
Private and Confidential Enter Date Here page 28
Alarm Events
Water heater temperature too low (next slide)
Water heater temperature too high (Y2 > 150°F, R2 > 185°F)
Loss of power – relay closes
Loss of power for more than 8 hours – clock reset
Internal controller temperature too high (> 185°F)
Master/slave error
Private and Confidential Enter Date Here page 29
Water Heater Sensor (Optional)
Ensures maintain temp does not exceed the water heater temp
Controller stores highest water temperature measured over last 24 hours
Delta between supplied water temperature and the maintain temperature setpoint selected between 9°F and 27°F
Connected to single or master controller only
Sensor cable can be extended up to 328 feet
Private and Confidential Enter Date Here page 30
BMS Interface
BMS input is 0-10 Vdc
BMS controls the temperature setpoint
If water heater sensor is installed, it overrules the BMS temperature setting if necessary
Loss of power alarms BMS
Private and Confidential Enter Date Here page 31
Master/Slave Function
Control up to eight additional controllers
Total maximum length of cable between all controllers is 328 ft
RS-485 connection
Water heater sensor connects only to master controller
Controllers on the same phase (max 3 controllers) have a delayed On and Off
Private and Confidential Enter Date Here page 32
Multiple Circuits with Single Controller
For controlling multiple circuits with the same parameters (i.e. voltage, maintain temp, ambient temp, economy temp), connect the heating cable output relay to an external contactor coil
Private and Confidential Enter Date Here page 33
Power Correction Factor
Fine tuning of system
Increase or decrease the actual pipe maintain temperature
0.6 – 1.4 percent of duty cycle
Private and Confidential Enter Date Here page 34
Legionella ~ What is it?
Received its name from a 1976 break out at an
American Legion Convention in Philadelphia
Bacteria common to warm water environments
Cause of Legionellosis – any illness caused by the
bacteria (Legionnaires’ disease and Pontiac Fever
most common)
Attacks the respiratory system
Private and Confidential Enter Date Here page 35
Legionella ~ www.awt.org
Legionella 2003: an Update and Statement by the
Association of Water Technologies (AWT)
“raising water temperature to 122˚F = a 90% kill of
legionella in 2 hours, 140˚F = a 90% kill of legionella
in 2 minutes and 158˚F = a 100% rapid kill of
legionella.”
Private and Confidential Enter Date Here page 36
Hot Water Temperature Maintenance
Questions?