Hot Water and Solar Hot Water

1. Hot Water and Solar Hot Water Dr. William J. Makofske Sustainable Warwick Warwick Town Hall October 29, 2008

2. Household Hot Water Hot Water consumption � 20 gal per person per day Daily basis for showers and baths, for washing dishes and clothes, as well as other purposes. For a family of 4, it will consume around 200 gallons of oil a year (assuming a 70% efficiency). About 25% of home energy consumption Water is typically heated by a variety of fuels (oil, natural gas, propane) and also by electricity. All these methods use up valuable natural resources and create significant pollution. Solar hot water is a viable option..

3. The First Step�Conservation & Efficiency Since solar hot water systems are not cheap, it makes economic sense to reduce hot water use and improve efficiency of use so that the solar system can be the smallest possible size to meet your needs. Conservation and efficiency are usually the cheapest approaches to reducing energy use. Reduce Demand: Low-flow shower heads Add faucet aerators Lower water-use clothes washers and dish washers Take shorter showers Reduce Heat Losses Insulate hot water tank Insulate hot water pipes Efficient Technology Efficient water heaters On-demand water heaters Solar water heaters

4.  Solar Hot Water  Will supply about 75% of your hot water needs over the year if sized properly. . Almost all solar hot water heaters use an auxiliary backup system when the sun is insufficient.

5. Other Applications of Similar Technology Pool heating Space heating of buildings Absorption air conditioning Concentrating collectors for high temperature water for industry uses and for power production

6. Batch Water Heaters Batch water heater on a roof in Greece. Sun heats the tank in an enclosed insulated box with glazing. Greece has a non-freezing climate.

7. Thermosyphoning Systems in Greece The tank sits above the collectors. Hoses bring water to and from the tank. This is a non-freezing climate.