General Information

When choosing a solar system for hot water we must first determine our needs for hot quantity as well as in preferred temperature of consumption. The typical calculation for the temperature for consumption is 45ºC, but for the calculation of required quantity you must take into account the daily needs.

Calculation of needs for hot water usage
 
1) RESIDENCES  

In family residences, the needs for hot water remain stable during the whole year. An indication for the needs is given by the number of individuals living in the building  Usually, the daily consumption of hot water at 45ºC is calculated taking into consideration the following:

Low consumption:  30 liters per person/ day
 
Medium consumption: 40 liters per person  / day

High consumption: 60 liters per person / day

In the case where we want to connect to the solar installation the washing machine and the dishwasher, we would have to increase the calculated daily needs of consumption as follows:

20 liters / day (1 wash per day)

Dishwasher: 20 liters / day (1 wash per day)

Example:

A family of 4 persons needs around 240 liters of hot water daily in order to have a medium daily consumption. (40 liters per capita x 4 persons). If we include a washing machine and dishwasher, then we must calculate a consumption of 200 liters per day.