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Solar Hot Water


The integral passive solar water heater (IPSWH) combines solar collection with storage. A typical IPSWH includes one or a series of tanks that are painted black or coated with a selective surface (that absorbs more than it reradiates) to absorb heat from the sun. They are enclosed in an insulated box and covered with glazing material. A wide variety of configurations are possible, with differing costs and performance. The performance of a good IPSWH approaches that of a flat plate system. And the IPSWH will last longer than an active system and costs less to make and install. One recent comparison study found the IPSWH to be the most cost-effective solar water system even in a cold 6,000 Cooling Degree Day climate. They do even better in warmer climates.


solar hot water, integral solar water heater, integral passive solar water heater, IPSWH, integral collector system, batch water heater, direct thermal water heater, breadbox water heater, low cost, long life, selective surface, simple solar hot water, seasonal performance, freeze resistance, thermal mass, insulated lids, single and double glazed, Heat Mirror©


Bainbridge, D. A. 1981. Integral Passive Solar Water Heaters. Passive Solar Institute, Davis, CA. 99 p.

Bainbridge, D. A. 2008. Solar hot water San Diego. ASES Note. (incomplete draft)

Bainbridge, D. A. 2007. The management failure of the American utilities: the case of solar hot water. Proceedings of the Society for Advancement of Management International Business Conference, Las Vegas, NV March 25-28, 2007. 685-693

Bainbridge, D. A. 2007. Build your own passive solar water heater. Mother Earth News. Oct./Nov. 79-86.

Bainbridge, D. A. 2005. Whatever happened to solar hot water? 2p. draft

Bainbridge, D. A. 1981. Integral passive solar water heater performance. pp. 163-167. J. Hayes and W.A. Kolar, eds.6th National Passive Solar Conference Proceedings, Portland, Oregon, American Section, International Solar Energy Society,.

Bainbridge, D. A. 1981. The integral passive solar water heater book. Alternative Sources of Energy. 50:49-50.

Bainbridge, D. A. 1981. A Three Tank Integral Solar Water Heater - Plan. 15 pages (draft).

Bainbridge, D.A. 1981. Integral Passive Solar Water Heaters: Introduction. 25 p. 

Bainbridge, D. A. 1981. Book review: Handmade Hot Water. Solar Age. (no final file copy)

Reiss, J. and Bainbridge, D. A. 1978. Breadbox design. Alternative Sources of Energy. October. 16-21,46-47. plus performance charts

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