Key Takeaways from the Industry’s Governing Bodies (1 of 3)

Who creates Safety Performance standards?

UL (Underwriters Laboratories): Establishes the minimum requirements for Electric water heater safety.

UL174: Residential Electric Water Heaters –12kW and less
UL1453: Commercial Electric Water Heaters –Greater than 12kW

ANSI (American National Standards Institute): Establishes the safety & construction standards for Gas products.

Z21.10.1: Residential Gas Water Heaters –75,000 BTU/Hr. and less
Z21.10.3: Commercial Gas Water Heaters –Greater than 75,000 BTU/Hr.

DOE (Department of Energy)

EPCA was enacted in 1975, which then led to the first NAECA (National Appliance Energy Conservation Act) in 1987. The Energy Policy Act of 1992 (EPAct) covers commercial products.

ASHRAE (American Society of Heating Refrigeration and Air Conditioning Engineers)
Sets the minimum requirements for overall efficiency of buildings with the exception of low-rise buildings.

ASHRAE 90.1B –pertains to minimum efficiency of all water heaters installed in buildings.

Reducing the Impact of Water Softeners on Heaters

There are other elements in water besides H₂O, such as calcium and magnesium. The concentration of these minerals depends on geographical location and the water source (municipality or a private well). A high concentration of these minerals is what commonly creates the condition know as “hard water”.

Hard water can be a nuisance, clogging or corroding pipes and fixtures, thus ultimately impacting the comfort of your shower or bath.

The installation of a water softener is a common solution to this issue.

How a Water Softener Works - A softener replaces the calcium and magnesium ions with sodium ions.

The Problem -The exchange of calcium and magnesium ions for sodium ions, results in the water being more conductive. The higher conductivity of the water will cause the water heater’s anode rod to deplete more rapidly. Once the anode rod is depleted, the tank is more susceptible to corrosion.

Solution-Bradford White’s operation manuals recommend the inspection of anode rods every two years. If using a water softener it is important to inspect the anode rod more frequently, and to replace it if necessary.

The anode rod is a crucial part to ensure the longevity of a water heater.

Negative Air Pressure

Negative air pressure is the flow or movement of air from the outside to the inside of a building.

Devices that pull air out of the building can create negative air pressure. This is especially true in dealing with kitchen or restaurant product applications. Cook top fans can move 200-400 cubic feet of air per minute, generating an enormous amount of negative air pressure. The use of exhaust fans, clothing dryers, furnaces, central vacuums or additional hood ranges may increase the presence of negative air pressure.

Possible Negative Air Pressure Issues:

  • Slower recovery times
  • Pilot flames will not stay lit
  • Presence of Carbon monoxide
  • Sooting around the burner assembly
  • Flame rollout on heavy duty commercial models (Non FVIR models)
  • Excessive condensation

Bradford White recommends installing power direct vent water heaters such as our ultra high efficiency eFSeries® in these applications, where negative air pressures are possible. Direct vent water heaters, both power and non, will reduce the potential of performance problems, nuisance outages, and premature failure of the water heater.

When too much negative air pressure is present, a building tries to replenish by engulfing positive air from the outside as much as possible.

Energy Conversion & Amp Draw

Sometimes buildings or homes switch energy sources and want the same performance out of their water heaters regardless of the energy source.

Here are simple formulas to convert back and forth between gas and electric:

Gas to Electric: kW = (BTU/Hr.) / 3,412
Electric to Gas: (BTU/Hr.) = kW x 3,412

Have you ever been asked  “How many amps does a water heater use?”

Here is a simple formula to figure out the amp draw:

Single Phase: Watts/Volts = Amps
Three Phase: Watts/(Volts x 1.732) = Amps
Three Phase (unbalanced): Watts/Volts = Amps

Please use these formulas to help in determining proper recovery amongst different fuel sources and helping to determine amp draw.

Usable Storage

Do you know the difference between tank capacity and usable storage?

When a water heater’s approximate set point temperature is satisfied and is in “stand by” mode there is approximately 70% of the total tank capacity available.For example, if a 100 gallon water heater’s set point temperature is satisfied, there will be approximately 70 gallons of the stored temperature available for immediate use.

Knowing this helps with accurately sizing applications, especially when a specific “dump capacity” is needed.

You can use the formula shown below in commercial applications that require a larger dump capacity. (Car washes, large showers, etc)

Usable Storage Formula with Blend Factor

  1. (Delivered Water Temp –Cold Water Inlet Temp) ÷ (Water Set Point Temp –Cold Water Inlet Temp)  = Blend Factor
  2. Useable Storage of Tank† ÷ Blend Factor  = Gallons of Useable Water at Delivered Temp

Example: 100 gallon water heater
Incoming Water Temp = 40°F; Water Set Point Temp = 160°F
Delivered Water Temp = 120°F

  1. (120-40)/(160-40) = 80/120 = .6666
  2. (100 x .70)/.6666 = 105 gallons of usable storage
†(Usable storage = 70%)

SNF Regulations

Are you getting questions about NSF? Is Bradford White compliant with NSF? What is it?

NSF was founded in 1944 as the National Sanitation Foundation.

NSF 372 – Bradford White carries this certification mark on ALL water heaters as certified and displayed by CSA “Low Lead”.
Purpose - This standard establishes procedures for the determination of lead content based on the wetted surface areas of products. This standard applies to any drinking water system component that conveys or dispenses water for human consumption through drinking or cooking.

NSF 5 – Bradford White carries this certification mark on LDCE, LDCG, Commercial Electric, & Commercial Gas products through the use of kits.
Purpose - This Standard establishes minimum public health and sanitation requirements for the materials, design, construction, and performance of commercial water heaters, hot water supply boilers, and heat recovery equipment. This Standard does not contain safety requirements.

Please know NSF 5 Kits are available- Bradford White offers NSF kits for all qualifying heaters. Open combustion models use a leg extension kit (bottom left image). Down fired burner models and electric models all use a sealant (bottom right image). 

Gas Venting Types

Edition #5 | May 2016

Non-Mechanical

  • Uses the density difference between hot exhaust & cooler ambient air
  • Negative vent pressure

Atmospheric Vent

  • Most common venting style, also known as “Chimney Vent”
  • Uses surrounding air for combustion and exhausts through the flue
  • Vents with B-vent or lined chimney
  • Must use a draft diverter

Direct Vent

  • Uses outside air for combustion and exhausts to the outside (concentric vent) (pipe within a pipe)
  • Vent goes out the wall not through the ceiling
  • Does not require any power (standing pilot)

Mechanical

  • Uses a powered blower to expel exhaust gases through the vent system
  • Positive vent pressure

Power Vent

  • Uses inside air for combustion and vents either horizontally or vertically using PVC, CPVC, or ABS material
  • Uses 1 pipe for venting the exhaust
  • Requires power to vent exhaust (blower motor assembly)

Power Direct Vent

  • Uses a twin pipe system, pulling air from the outside for combustion and venting exhaust to the outside with a separate pipe (sometimes concentric)
  • Typically installed in applications where there is a lack of combustible air
  • Requires power for intake and exhaust (blower motor assembly)

CTRL + F

Looking for a quicker way to search for important information in your Bradford White documents?

Use CTRL + F

  1. Simply hit “Ctrl” and “F” at the same time and a search bar will appear.
  2. Type the key word, or words, you are looking for and those words will be highlighted.

The following example is searching for venting information in an I&O manual.
HINT: Truncate the search word to eliminate overlooking your desired section.

You can use this on any website or any document! For example; operation manuals, service manuals, electronic wholesale price books, parts lists and more!

Recovery Rates

Recovery Rates can be calculated at any Temperature Rise

Gas Water Heaters

All you need is the spec sheet or pocket catalog, and a calculator.

  1. Take the known GPH recovery and multiply by known temperature rise.
    - 145 x 100 = 14,500
  2. Then divide by your desired temperature rise (Ex. 80°F)
    - 14,500/80 =181.25
  3. The EF60T1253N will recover 181.25 GPH at an 80°F temperature rise.
    SIMPLE! This works with any product we have listed.

Electric Water Heaters

kW input will recover at the same rate, regardless of gallon capacity.
Use this chart for quick recovery results! The chart can be found on both Heavy Duty commercial electric spec sheets.
Don’t see your desired temperature rise listed? Use the formula above for any other temperature rise.

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