Since July 2008, it has been mandatory for all newly built residential and non-residential buildings in the Brazilian city of São Paulo to install a solar water heating system on their premises (see http://www.solarthermalworld.org/node/631). São Paulo is one of the leading cities in Brazil with a population of 11 million.
Some of São Paulo’s private sector companies have recently launched a sizing tool aimed at professionals involved in such installations, in order to facilitate the design and sizing of these solar projects. This new tool includes an Excel-based calculation sheet and a paper explaining the methodology behind sizing solar hot water systems for multi-family buildings - except for the sector of social housing.
The calculation method is in accordance with the solar law of São Paulo, No. 14 459 from 3 July 2007, and Decree No. 49 148 from 21 January 2008. The law stipulates that at least 40 % of the annual heating demand must be provided by a solar system. The authors of the present paper consider the figure to be a minimum requirement and emphasize that “a solar share of close to 70% of annual hot water demand is ideal”.
The paper and the parameters for the calculation tool were developed by a working group composed of members from the following three associations: ABRASIP (Brazilian Association of Building Engineering Services), ABRAVA (Brazilian Association of HVAC-R) and ABRINSTAL (Brazilian Association for Compliance and Efficiency of Installations). The document gives only recommendations, but does not replace the necessary and detailed design schematics of solar heating systems and their proper integration into a building.
Attached you will find the paper describing the sizing tool. The Excel calculation sheet can be ordered by email to Brazilian consultancy SE-Studio Equinócio – Marca Solar Group: firstname.lastname@example.org.
This text was written by Carlos Faria Café, Director of SE-Studio Equinócio – Marca Solar Group based in Brazil