Solar Hot Water Panels use the energy from the sun to heat water through flat glass covered panels or evacuated tubing systems which consist of two glass tubes fused at the top and bottom. The space between the two tubes is evacuated to form a vacuum. A copper pipe running through the center of the tube meets a common manifold that is connected to a hot water storage tank.
There are two types of solar hot water systems: active, which have circulating pumps and controls, and passive, which don’t. Pumps circulate a non-freezing, heat-transfer fluid through the collectors and a heat exchanger to keep them from freezing in the winter (typically glycol).
Potential Dangers to consider
- Broken glass – some manufacturers have more durable glass than others
- Scalding - Over temperature relief valves are designed to dump all the hot water from the hot water tank until the sensor sees temps are less that 203°F or so. Ensure that the relief line is correctly located to discharge in an area to prevent burns to construction workers during commissioning and operations.
- Chemical exposure – check anti-freeze MSDS before adding to system
- Access - How will workers get to the installation? Is there stair access? Will scaffolding or a ladder be required?
- Fall Protection - All employees working on the roof should be tied off unless additional safety features such as catch platforms have been installed.
- Overhead Protection - Will work be taking place beneath the solar hot water panel installation? If so, what steps have been taken to prevent broken glass, materials, or equipment from falling through and striking workers below? Do workers beneath the installation know that there is overhead work taking place?
- Scheduling – If possible, the solar hot water panel installation should be scheduled near the end of the project to minimize risk of damage or injury.
- Material Delivery & Rigging – It is important to ensure boxes of glass are properly secured during rigging so nothing drops when it is being hoisted to the roof. Once on roof check carefully to ensure no breakage has occurred.
- Environmental Factors – Is the installation happening during the winter? If so how are you dealing with rain/slip hazards? Is there a chance there may be ice on the roof? Additional environmental concerns include strong winds, lightening, and excessively hot days where heat exhaustion can impact workers on the roof.
- Pre-read the Tool Box Talk. Your comfort level and confidence will be higher if you know your topic.
- Discuss related tasks, work areas or events that make the Tool Box Talk relevant to your jobsite.
- Involve the workers by asking questions and input that drives discussion. Funding and support for this project has been provided by the State of Washington, Department of Labor & Industries.
Questions for Discussion:
- Where is it located?
- Which trades may be in a new situation? How is it sequenced?
- What equipment & materials are involved? How is it installed?
- How is it operated & maintained