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The "E" system operates similarly to the SHEM 80DB in that the tank is hooked up in a drainback configuration with solar panels, with solar energy providing upwards of 75% or more of the energy for hot water. However, when there is insufficient solar resource, the backup heating element directly provides supplemental heat for hot water. The differences between the "E" system and a regular drainback system is the heating element, the controller and the relay switch. The "E" controller has a battery backed up timer that allows the element to operate only during pre-determined times, and at pre-determined temperatures. The "E" controller has an optional Heat button. This button activates the electric element manually, at any time of day. Simply press the Heat button, and wait approximately 5 seconds to hear the relay activate and the element come on. NOTE: The "E" controller operates on military time! Factory settings for the "E" controller operate the element at the following times and temperatures: • 4 A.M. to 7 A.M., heating to a temperature of 160° degrees (if tank below 150°) • 10 A.M. to 10 A.M., this is the second heating slot, and is not active as set • 16:00 (4:00 P.M) to 19:00 (7:00 P.M), heating to 160° (if tank below 150°) NOTE: The above temperatures will develop 55-60 gallons of 110° degree water in the morning, and again in the evening. The total expected output from an "E" tank is approximately 50-60 gallons in the morning, and 55-60 gallons of hot water again in the evening (where there is only electric heating i.e. no solar resource). The "E" controller uses a third temp sensor in the top of the tank to switch the heating element on and off. The third sensor is needed because of water temperature stratification when the heating element is used. Without outside agitation the water above the heating element is generally the only water that gets heated by the heating element. In order to get accurate readings of the temperature of the water being heated by the element, a T3 sensor is needed above the heating element. What's included
Pricing Operation The 80E’s electric element is controlled by both a timer function and an activation temperature. Three time slots are available. During these time slots if the temperature is below a certain number, then the element is activated and runs until either the time slot ends, or the temperature of the tank hits a certain max temperature set by the user. Using factory settings, only 2 of these time slots are utilized. However, the third one can be set up by the user. When resetting time or temperature settings, please remember to use only military time, and to set times to be sequential order. Using factory electric element settings, the tank takes maximum advantage of solar energy by not allowing the element to operate until after the solar day is done. You can set the tank to guarantee hot water when you desire. Please review and understand the controller manual before undertaking to reset options, as you could accidently reset options without knowledge or intent. Production The diagram below shows the solar output from a single 4' by 10' flat plate collector (dark blue) and hot water demand (light blue) for a typical family of 4 in Louisiana. Notice that in the summer months, there will be ample solar hot water. In the winter months, the electric element (or other backup system) will be required to supply hot water. In this example, additional collectors would boost the solar fraction (energy provided by the sun), and the element would not have to work as hard.
The electric element can produce enough hot water for several showers. The element can recharge the tank from 105°F to 160°F in just over two hours. The recharge rate is approximately 1 degree rise every two minutes. Starting from 105°F the water should be got enough to produce one shower’s worth of water in just about an hour. When the tank is at a temperature of 160°F, at least 60 gallons of 110°F can be produced by the tank.
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