Water Heaters

Heat Pump Hot Water Systems

Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. Therefore, they can be two to three times more energy efficient than conventional electric resistance water heaters. To move the heat, heat pumps work like a refrigerator in reverse. The energy savings is 60% less than conventional electric water heating.

While a refrigerator pulls heat from inside a box and dumps it into the surrounding room, a stand-alone air-source heat pump water heater pulls heat from the surrounding air and dumps it—at a higher temperature—into a tank to heat water.

Heat pump water heaters require installation in locations that remain in the 40º–90ºF (4.4º–32.2ºC) range year-round and provide at least 1,000 cubic feet (28.3 cubic meters) of air space around the water heater. Cool exhaust air can be exhausted to the room or outdoors. Install them in a space with excess heat, such as a furnace room. Heat pump water heaters will not operate efficiently in a cold space. They tend to cool the spaces they are in. You can also install an air-source heat pump system that combines heating, cooling, and water heating. These combination systems pull their heat indoors from the outdoor air in the winter and from the indoor air in the summer. Because they remove heat from the air, any type of air-source heat pump system works more efficiently in a warm climate.

Call Tn Home Craft today for more information on water heating for your home. 865-936-4901

Solar Hot Water Systems

Solar Domestic Hot Water systems are a great way to save money, cut down on the use of fossil fuels and do a big favor for the environment.  We have installed many of these systems over the last two years and they work very well, even in the middle of winter.

AET AE-40 collectors on roof. The system components consist of Flat Plate collectors:

These are Alternative Energy Technology AE-40 collectors. They are elevated slightly from the roof pitch to facilitate snow removal and better drain back performance. They are also tilted to the left so that the water drains out of the bottom of the collectors when the pump is off. This is a very important detail to avoid freeze damage.

The piping is 3/4 L copper tubing insulated with closed cell (AKA Rubatex or Insultube) R-5 foam insulation.  Where ever possible, the insulation is slid over the ends of the pipe instead of cut lengthwise and placed over the pipe.  The ends and any slit pieces are glued together with special glue called R-420.  The exterior runs are covered with PVC jacket to protect the insulation from UV damage and improve the system appearance.

The drain back tank is mounted on a shelf attached to the basement wall.  This is a 10 gallon stainless steel drain back tank with an internal heat exchanger.  It has a sight glass which is marked with the proper fluid levels for when the system is running and when it is off.

The solar loop pump is a TACO 009BF5.  I use bronze pumps in the solar loop of a drain back system because the water gets sloshed around quite a bit and becomes oxygenated.  A cast iron pump will rust and foul the site glass.  It also keeps the solar loop a “potable water system” and thus avoids any questions about the single wall heat exchanger in the drain back tank.  The pump is mounted below the lowest fluid level in the drain back tank.  At the very bottom of the solar loop is the drain valve.

The storage tank loop is a TACO 006B4.  This is a larger pump that normal because the storage tank is located about 15 feet away in another room.  This configuration is slightly unusual. However, it was the only way to fit the solar system in a crowded basement.

In the storage tank loop there is an air vent at the highest point in the loop to bleed out any air that may become trapped in that loop.  Trapped air can cause pump cavitations and or reduce the flow in the loop storage tank loop.  For maximum efficiency, the loop needs to move about 4-6 gallons per minute from the bottom of the storage tank through the heat exchanger and back to the top of the storage tank.

The storage tank is an 80 gallon off the shelf unit with a 12 year tank warranty.  It has electric back up elements which are not connected because the home owner has an indirect oil fired tank connected to their home heating system.

The system controller is DTC-2 (AKA Eagle 2) by IMC.  I really like these controllers because they have temperature reading for the storage tank and the collectors.  They also have variable set points for the high limit and temperature on differential.

Solar water heaters, or sometimes called solar domestic hot water systems, are a cost effective way to produce hot water for your home or business. They can be used in any climate, and because they use sunshine as their fuel source, it’s absolutely free.

The Environmental and Energy Study Institute (EESI) states that there are a million and a half solar water heaters already installed in U.S. homes and businesses. Solar water heater systems operate in any season and according to EESI estimates, 40 percent of homes in the United States have adequate access to the sun which would currently allow close to 30 million additional solar water heaters to be installed.Another great reason to switch to a solar water heater is finantial in nature. Solar water heater systems cost between $1,500 and $3,500, but with savings in electricity or natural gas, solar water heaters pay for themselves within four to eight years. And solar water heaters last between 15 and 40 years so after that initial payback period is up, the energy is absolutely free for the remaining life of the system.

Tankless or On-Demand Water Heaters

Tankless Water heaters are also called on-demand water heaters. These provide hot water right where you need it, when you need it, without a storage tank. Using electricity, gas, or propane as a heat source, tankless water heaters, in some cases, can cut your water-heating bill by 10 to 20 percent. The savings come by eliminating standby losses – energy wasted by warmed water sitting around unused in a tank.

Units large enough to supply hot water for an entire house can be located centrally. More commonly, tankless water heaters usually sit in a closet or under a sink where its hot water is used.

A tankless water heater can supplement a regular water heater in a distant location, or it can be used for all your hot water needs. But be aware that they aren’t appropriate for all applications, and that sometimes they won’t save that much energy or money.

Residential-sized gas-fired models that are now on the market supply only five gallons of water heated by 90 degrees per minute – a comfortable enough output for a house with one or two people. If you have a large family, however, and need to do laundry and wash dishes at the same time others shower, a tankless system probably won’t meet your needs. Electrically heated models provide even less hot water than gas models – more like two gallons a minute, heated 70 degrees.

Call Tn Home Craft today for more information on water heating for your home. 865-936-4901