All Systems include:

• Solar Collectors
• Storage Tank with Heat Exchanger
• Water Reservoir
• Differential Termperature Controller
• Fluid Circulating Compnents
• Circulation Pump
• Installation Manual
• Mounting Hardware

Tropical Systems

» "D" (Differential Control) System - Open Loop

» "DPV" PV Drive System - Open Loop

» "FF" Free Flow System - Thermosiphon

» Sav'n'Sun™ "DX" Drainback Kit

*click any system for full-details

"D" System - Differential Control

This is the type of system most common in the Southern United States and Tropical Climates. As illustrated in Figure 1, the system consists of solar collector(s) installed on the roof and a hot water storage tank usually located in the garage or utility room. An alternating current (A/C) pump circulates the water from the tank up to the collector and back. This system is referred to a direct because the sun’s heat is transferred through the collector directly to the potable water. No antifreeze solution or heat exchanger is required.

The “D” System utilizes a differential control to sense the temperature differences between water leaving the collector and the coldest water in the bottom of the storage tank. The control turns the pump on when the water in the collector is about 20F warmer than the water in the tank. Similarly, the pump is turned off when the temperature variation is approximately 5F. This process ensures that the water is always being heated while the pump is operating.

A thermally operated valve is in-stalled at the collector to provide freeze protection where required. This valve will open to let warm water flow through the collector whenever temperatures approach freezing. As an alternative, the collector can be manually drained by closing the isolation valves and opening the drain valves (located above the storage tank).

Read Open Loop Specifications

Direct (Open Loop) "D" System (above)

"DPV" Direct PV System
PV Drive

The “DPV” System is identical to the “O” System except that a photo-voltaic panel provides the energy required to power the pump. The solar panel converts sunlight into electricity. This electricity then powers the direct current (DC) pump. Thus water circulates through the system only when the sun is shining.

The DC pump and solar panel are suitably matched to ensure proper performance. The pump starts when there is sufficient solar radiation available to heat the thermal collector. It shuts off later in the day when the available solar energy diminishes. As in the “D” System, a thermally operated valve provides freeze protection or the collector can be manually drained.

Read Open Loop Specifications

PV Direct (Open Loop)
"DPV" System (above)

"FF" Free Flow System

The Free Flow (FF) System is widely accepted throughout the world today. It is automatic, simple and reliable. Figure 6 illustrates a typical system.

All “FF” Systems have their collector(s) positioned lower than their tank(s). AS the sun heats the water in the collector it “rises” into the tank in the same way that a balloon “rises” in the air. The cold water in the tank then “sinks” into the collector. These events create a continuous process which results in a full tank of hot water by the end of the day.

The “FF” System does not require a pump or control. Cold water flows directly to the thermosiphon tank on the roof where the water is heated. Solar heated water then flows from the thermosiphon tank to ground level where it is ready to use.

Sav'n'Sun DX Drainback System
The Natural Solution for Hot Water

Sav’nSun is a packaged, fully integrated residential hot water system designed for the energy-minded homeowner who wants both savings and leading-edge technology that contributes to a cleaner environment.
Sav’nSun is delivered complete with AET collectors, a 50, 80, or 120 gallon storage tank, top mounted Drainback Reservoir with heat exchanger, freeze-protected drainback design, fluid handling package, and back-up heating element, making the system suitable for all climates.

A Retrofit Kit is also available to convert any existing water heating system into a solar water heating system using the Drainback Reservoir with heat exchanger and Solar Collectors. Please contact AET for sizing information.