Types of Water Heaters

A water heater uses a heating source to raise the temperature of incoming cold water from a municipal main or well. The heated water is stored in a tank and distributed on demand to showers, bathtubs, sinks and other water-using equipment in the home. Several types of water heaters are available:

• Storage tank water heaters
• Tankless water heaters
• Integrated space/sater heating systems
• Solar water heaters
• Heat pump water heaters

Storage Tank Water Heaters

Electric Water Heaters
Gas Water Heaters
Oil Water Heaters

Storage tank water heaters are by far the most common type used in Canada. These systems heat and store water in a tank so that hot water is available to the home at any time. As hot water is drawn from the top of the tank, cold water enters the bottom of the tank and is heated. The heating source can be electricity, gas or oil.

More efficient storage tank water heaters can perform as much as 40 percent better than conventional models. An energy-efficient model will typically have one or more of the following features:

• extra tank insulation for better heat retention and less standby loss (loss of heat through the walls of the tank)
• a better heat exchanger to transfer more heat from the energy source to the water
• factory-installed heat traps, which allow water to flow into the tank but prevent unwanted flow of hot water out of the tank

Energy-efficient gas-fired storage tank water heaters may include additional design features, such as:

• electronic ignition, which saves energy by eliminating the need for a continuous pilot light
• powered exhaust
• improved control of flue baffle and flue damper, which reduces heat loss through the flue vent
• condensing heat exchangers, which greatly improve the overall efficiency
• oil-fired water heaters with state-of-the-art burners, which offer high-efficiency performance and minimal stack losses.

Tankless Water Heaters

Tankless Water Heaters

These systems (also known as demand or instantaneous water heaters) do not have a storage tank. They heat water only when it is needed, thus avoiding standby heat loss through tank walls and water pipes. The most basic units consist of either an electric element or a gas burner surrounded by flowing water.

Tankless water heaters are usually installed to serve a specific need near the point of use, such as under a kitchen sink. Depending on overall water usage, they may not have the capacity to supply an entire home with hot water. For this reason, they are often used as booster heaters to supplement another water heating system.

A relatively new tankless technology – the low-mass water heater – is capable of supplying much more hot water to the home. These systems are typically gas-fired with electronic ignition and power exhaust. This makes them more efficient than conventional tankless heaters. They can be connected to an external storage tank if necessary.

Integrated Space/Water Heating Systems

Integrated space/water heating systems combine the household heating requirement with the household hot water needs, saving money on total system installation. A single boiler is used, requiring only one combustion burner and one vent. Often these systems employ an insulated external storage tank with a high-efficiency low-mass boiler to heat the water, which then passes through a fan coil (as in a car radiator). The system then blows the heat around the house in a warm air distribution system, like a conventional furnace.

For integrated systems that do not use high efficiency boilers, the initial cost saving is soon eliminated by very low seasonal efficiency. The heater is sized to produce enough heat to warm a house on the coldest winter day. However, in the spring, summer and fall, when no heating is required, the same heater heats domestic hot water only. The effect is an oversized water heater that operates for several months of the year with a low heating demand – and low efficiency, as a result.

One type of integrated system that has been around for many years, particularly in the Maritime provinces, is a fuel-fired hot water boiler with a tankless coil water heater that uses a heat exchanger in the boiler to heat tap water but without a separate storage tank. The water flows through a coil inside the boiler whenever a hot water faucet is turned on. The drawback is that this system is dramatically less efficient in warmer months, when space heating is not required, as the boiler water must be kept hot all the time.

Heat Pump Water Heaters

Heat pump water heater (HPWH) technology uses electricity to move heat from one place to another instead of generating heat directly.

To understand the concept of heat pumps, imagine a refrigerator working in reverse. While a refrigerator removes heat from an enclosed box and expels that heat to the surrounding air, a HPWH takes the heat from surrounding air and transfers it to water in an enclosed tank.

A low-pressure liquid refrigerant is vaporized in the heat pump’s evaporator and passed into the compressor. As the pressure of the refrigerant increases, so does its temperature. The heated refrigerant runs through a condenser coil within the storage tank, transferring heat to the water stored there. As the refrigerant delivers its heat to the water, it cools and condenses, and then passes through an expansion valve where the pressure is reduced and the cycle starts over.

Solar Water Heaters

Solar water heaters use the sun’s energy to heat water. Active solar systems, on the other hand, use pumps and controls to move the heated water from the collector to the storage tank. In areas where the temperature drops below freezing, the fluid in the collectors is usually antifreeze, which is then run through a heat exchanger to heat the household water.

Solar systems can supply up to 50 percent of the energy needed to heat water for an average household (depending on climate conditions and water use). Since energy from the sun is free, solar water heaters can significantly reduce a household’s water heating costs – savings that in turn can offset the higher purchase and installation costs of a solar system.

Direct Open Loop Solar Water Heaters

 

Simply. Intelligent automation is the key to the Guardian Solar Water Heater’s outstanding efficiency and self-sufficiency. The Guardian Solar Water Heater will turn on and off daily, collecting heat whenever it is available. The automatic controller alerts the pump when to run. It also alerts the automatic check valve to open, simultaneously. The pump then circulates colder water (from the bottom of your special solar storage tank) through your solar collector(s), and returns the heated water to the tank. This cycle continues as long as sun is available to provide heat to your water. When there is no heat available, the controller turns the pump off, and closes the check valve to prevent any loss of heat from the tank.

Indirect Solar Water Heater with Propylene Glycol

 

The Guardian IP is an indirect solar water heating system is designed to accommodate climates where freezing weather occurs more frequently and a drain back system cannot be installed. The solar storage tank and the solar collectors do not differ from those utilized in the Guardian direct solar system. The only difference lies in the way that the water is processed through the solar collector and back to the storage tank; your potable water is heated indirectly through a heat exchange coil. The Guardian IP units’ automatic solar circulation pump sends a mixture of water and food grade propylene glycol through the solar collector and back to the heat exchange coil. Heat is transferred to your potable water via the exchange coil which is wrapped around the inner collection tank. The Guardian IP system is freeze proof because the solution in the solar loop is an 8:1 ratio of water and food grade propylene glycol. The Guardian IP solar system is only recommended in climates that experience frequent freezing conditions, and where a Guardian DB system cannot be installed so that it will drain.

Indirect Solar Water Heater – Drain Back

 

The Guardian DB is an indirect drain back solar water heating system designed to accommodate climates where freezing weather occurs more frequently. The solar storage tank and the solar collector(s) do not differ from the Guardian direct solar system, the only difference lies in the way that the water is processed through the solar collector(s). Rather than circulating your potable water directly through the solar collector(s) and back to the storage tank, your water is heated indirectly through a heat exchanger contained in the drain back tank. The Guardian DB utilizes two circulation pumps. One pump circulates water through the solar collector and back to the exchange/drain back tank. A second pump simultaneously circulates water from the solar storage tank into the exchange/drain back tank transferring the heat from the water that is being circulating through the solar collector(s) to your potable water. The system is freeze proof because all the water in the solar loop drains down into the small heat exchange/drain back tank when the solar circulation pump is turned off by the automatic controller. With no water remaining in the solar collector(s) or solar plumbing, no freezing of the system can occur. The indirect drain back solar system is the most efficient solar water heater design for climates that experience frequent freezing conditions

WH-40 Electric Water Heater Timer Single Pole 240V 40A

 

The WH40 provides a convenient external override switch. Utilities in many areas of the country offer two electric rates for residential or commercial customers. One rate has the regular daytime electrical rate, the other is “off peak” rate. The off peak rate provides customers with “lower-priced” electricity during the nighttime and weekend periods. These time switches allow the customer to shift electricity use into these off-peak time periods in an attempt to save utility costs. Resistive Wattage is 40 Amp @120 – 480 VAC; Tungsten Wattage is 40 Amp 120 – 277 VAC. Product features 2 HP (24 FLA) 125 VAC; 5 HP (28 FLA) 240 VAC motor.

Honeywell Mixing Valves /p>

The Honeywell AM-1 series accurately adjusts, maintains and limits the hot water temperature to a desired setting selected by the user. In domestic water applications it offers scalding protection and bacteria growth control. By installing a Honeywell AM-1 mixing valve and raising water heater storage temperature setting and limiting mixed outlet water temperature to safe temperature more usable hot water is available. In heating applications it provides comfort and protects the equipment.

Honeywell Mixing Valves Features:

Dual purpose mixing or diverting valves
Constant water temperature under changing operating conditions
Reliable performance at minimum flow of 0.5 gpm
Proportional valve (simultaneous control of hot and cold water)
Energy savings through lower supply temperatures
Anti-scald, anti-chill thermal shock protection
Temperature lock at any point or high/low range
Nickel-plated brass/bronze construction, EPDM O-rings
All brass proportioning shuttle
Straight through design (hot and cold at the same level)
Maximum pressure 150 psi (1034 kPa), temperature 212°F (100°C)
Designed for easy maintenance and element replacement
Teflon® coated to prevent mineral build-up and extend life
Tamper evident design
Valve trapping not required

 

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