Hot Water Systems

Diagrams of solar hot water heating systems. These were prepared for the Alternative Energy Club as part of the "Intro to Solar Hot Water" presentation.

Supplementing a Conventional Hot Water Heater

In this scenario the roof-mounted collector is used to preheat the water that runs through the conventional hot water heater. The hot water heater will only need to run on cloudy days or during periods of heavy hot water use. This is an excellent way to reduce your use of fossil fuels without sacrificing the luxury of continuous hot water.

Unsupplemented Flat Panel Collector

This design has two parts: the collector and the storage tank. The collector is positioned to receive maximum sunlight. Cool water is pumped from the base of the storage tank into the collector. The sun warms the water and it travels back into the storage tank and then into the house. This system is at a disadvantage on cloudy days because it has no back up heating method.

System with On-Demand Tankless Water Heater

In this arrangement an "on-demand" gas hot water heater acts as a supplemental water heating system. Water heated by the collector is stored in a tank before moving into the on-demand heater and then into the house. While more expensive than conventional hot water heaters, on-demand heaters are more efficient and rapidly heat only the water that is being used. "On demand" hot water systems are also known as tanless water heaters.

Hot Water System with Heat Exchanger

The collector in this design is a closed loop system. Liquid is heated in the collector and then travels through a coil inside a hot water tank. Heat transfers from the coil into the freshwater tank. The closed loop, heat exchange system is advantageous for use in cold climates, because an anti-freeze solution can be used in place of water in the collector.

Roof Mounted Tank and Collector

This design illustrates a commercially available hot water system in which the tank and the flat panel collector are integrated. No pump is required to run this system and installation is fairly simple. The On-demand hot water heater functions as a back up system.

Attic Tank and Roof Top Collector

Storing the hot water tank in the attic has its advantages. The attic provides the storage tank with excellent protection from the elements, allowing hot water to be stored for longer spans. Also, gravity carries water into faucets without the aid of a pump.