DIY Solar Hot Water – Mounting the Panel


This is the fourth article in our new series on building a DIY Solar Hot Water Heating System.  In article 3, we reviewed the panel build and prepared it for mounting.  In the article, we will present the mounting very cost effective and functional approach that we ended up using.

Locating the Panel Installation

When considering a location for mounting the panel, be sure to choose a south facing spot, free of shadows from buildings and trees.  Consider how the shadows will change throughout the day and throughout the seasons.  Remember that the sun will be lower in the sky during the spring and fall and much higher in the sky during the summer.

Orienting the Panel

Once you have chosen your location, the next step is to determine the orientation of the panel so that it receives as much sun as possible during the seasons that it will be operating.  Consider both the elevation and the azimuth of the panel. Elevation is another name for the tilt angle from horizontal that the panel will be mounted.  Azimuth is another name for the compass direction that the panel is pointing.

The elevation and azimuth will need to be adjusted depending on the latitude and longitude of the site.

In short though, a good rule of thumb is to orient the panel to point as due south as possible with an elevation 2-5 degrees higher than the site latitude in the spring and fall and 2-5 degrees lower than the site latitude in the summer.  This means that if your latitude is 45deg North, tilt your panel to 47-50deg off of horizontal in the spring and fall and 43-40 deg off of horizontal in the summer.  These angles are just starting points. You may wish to experiment to obtain the best results for your location.

Tilting the solar panel helps to ensure that the panel is receiving the suns most direct radiation which helps the panel capture more of the heat.

Here is the first panel built by the author. It is mounted using 4 door hinges along the bottom of the panel frame. Note the blue vent pipe on the top left and the insulated hot water pipes in the aluminum cover on the lower left.  The system is drained in the cold winter months.

A Simple Design for a Tiltable Solar Panel Mount

There are a number of companies that sell very expensive solar panel mounts that tilt and track the sun.  In this DIY solar panel build, we are focusing on cost, functionality, ease of build and reliability.  All together, those attributes mean we need to think outside the box, and a commercially made panel mount is certainly outside the scope of this build.  So how do we build a tiltable panel mount that will meet those criteria?  It’s actually pretty simple.

Add a horizontal 2″x4″x8′ wood beam across the back of the panel, along the bottom edge.  This beam will support the panel and provide further rigitidty to the frame.  The tiltable feature of the panel frame will be provided by 4 low-cost door hinges.  No need to spend a lot of money, just get some normal door hinges.  Then, mount the door hinges to the new beam.  Once mounted to the beam, the hinges can be mounted to the roof or other mounting location.

Setting the tilt angle for the solar panel

To hold the panel at the desired angle, use 2″x4″ cutoffs to hold the back of the panel up.  There should 4 2″x4″ pieces bracing the panel up.  Screw the braces into the panel and into the roof (or wherever the panel is mounted).  These braces may seem heavy, but they will not only provide for the angle holding, but will also enable the panel to withstand fairly strong winds.

2″x4″ support beams in the back of the panel. These hold the panel at the correct angle and also provide stability and structural rigidity in the wind. Note the copper strapping along the sides of the panel. The copper straps provide further connection to the roof in order to protect from high winds. This panel mount approach has survived 50+ MPH winds.

Routing pipes and sensors to the panel

When you choose a mounting location for the panel, be sure to consider how the water pipes and sensor wires will be routed to the panel.  In the case of our first panel, the pipes and sensor wires are routed across the left of the garage roof and then down into the garage through the garage wall.  We will go into more detail about piping and sensors in a following article.