Sizing Information

Contribution

Depending on your region and size of system solar can provide between 50-80% of your domestic hot water needs. A properly sized system will provide almost all of a homes hot water in the summer months. The chart below will give you an idea of what solar collectors and configurations are recommended for your use.

This document is meant to aid the sizing of residential hot water systems, solar combination systems and solar pool heating. The sizing above is a guide, any system should be designed and installed by qualified persons. For complete sizing and installation information please consult the Apricus Installation and Operation Manual.

Sizing

The average person uses 20 gallons of hot water per day. Below, please find another tool to assist you in understanding the number of evacuated tubes necessary for your system. To use, follow the temperature rise curve for the average temperature rise in your region. The intersection will tell you how many tubes are needed to meet summer time energy demand.

Calculator

The following calculator allows you to determine how many tubes are required for temperature rises and water volumes not displayed on the graph above.  Generally the peak daily summer insolation levels should be used.
Please note:  1 kWh/m²/day = 317.1 Btu/ft²/day

*Water Volume = This should represent the actual volume of hot water used at the tap in total each day.  

**Temperature Rise = target tap hot water temp - average mains cold water temp.

Target hot water temp should usually be around 107^oF - 113^oF (42^oC - to 45^oC)

Apart from the three key factors used in the calculation above, you may also need to consider:
1. Annually/daily shade patterns
2. Angle/direction of installation (a less than ideal angle will reduce efficiency)
6. Installation site (Do you have enough room for the collector(s)?) 

Please remember the above is just a guide.  Please contact Apricus if you need more support with system sizing.