A DIY Solar Hot Water Heater

Here at the ranch, we are starting a new series on our latest build: a DIY solar hot-water heater. This series will be a summary of the build that was completed in the spring of 2015 and has been in service now for 2 seasons. In this build, the panel, heat exchanger and software control were all rolled from scratch.

System Overview

The design of the system is based on the typical indirect, active circulated approach.  Several improvements have been made in order to extend the season of the system here in the Mountain West.

Sizing a Solar Hot Water System

Building a DIY solar hot water system doesn’t have to break the bank.  Follow along as we lay out some basic rules of thumb for sizing a solar hot water system, and then make some choices based on project budget and available time.

The Panel:

The panel is a 4 ft x 8 ft custom built, copper tube unit with 17 horizontal tubes and 2 vertical headers with a bleed valve at the top.

The Heat Exchanger:

The heat exchange unit is a custom built coaxial copper exchanger with 4 parallel tubes and headers on each end.

The Storage tank:

The storage tank is a used 40 gallon gas heater tank.

The Controller:

The controller is running custom made software on a Raspberry Pi B+ platform.