Solar thermal is an excellent way to provide domestic hot water in non-residential buildings such as offices, factories, hotels, hospitals, visitor attractions or shopping centres etc. A solar hot water system can be used on virtually any site that has a domestic hot water requirement.

Detailed below is a description of the components, operation and installation etc. of a domestic LaZer2 solar hot water system for use in a non-residential building.

LaZer2 Solar Collectors

A southerly-facing pitched roof or wall, or a flat roof, are ideal locations for solar collectors to be mounted on. Collectors can be installed on an east or west-facing but the total collector area will need to be increased to compensate for the lower energy levels. Shading, aesthetics, roof condition and accessibility will all be considered when selecting a position for the solar collectors.

Once the average daily domestic hot water demand has been estimated and the collector location identified; the number of collectors required can be specified. As there is a fixed amount of solar energy available to the collectors; the larger the collector area the more energy will be absorbed.

Pipe Work

Pipe work will need to be run from the collector arrays to the solar calorifiers or cylinders. Copper pipe work is typically used but stainless steel is an option. The high operating temperatures of the system mean that plastic pipe work is not suitable.

Pipe work connections are usually low temperature braised or soldered connections. The solder used will need to have a melting point of c.300C

The size of the pipe work installed will depend on the total collector area and length of pipe run.

The pipe work can be run externally or internally. All pipe work will be insulated, and if required mechanically protected. As an anti-freeze is used in all systems no trace heating will be required.

Calorifiers or Cylinders

Hot water calorifiers or cylinders are always required to store the solar energy that the LaZer2 system is producing. The specification of the proposed (or existing) hot water system will influence the way in which the LaZer2 system is integrated and the type of calorifier or cylinders installed. The capacity of the hot water storage will be matched to the area of collectors specified as well as the hot water demand and usage pattern.

We would usually install solar calorifier to pre-feed the main hot water calorifier/s, or a calorifier that can be heated by both the solar collectors and the LTHW system or immersion heaters. The solution proposed will depend on control philosophy and plant room space etc. All solutions will incorporate controls to avoid the risk of Legionella.

If necessary, a thermostatic blender valve will be fitted to the output of the solar calorifier to automatically regulate the temperature of water reaching the taps. This helps conserve hot water and avoids the risk of scolding.


The LaZer2 solar control system will usually be installed close to the solar calorifier.

The control settings will be optimised at the time of installation, after which no user interaction should be required. The LaZer2 system operates automatically, but the readings on controller display and gauges should be monitored regularly to ensure that the system is functioning correctly.

The LaZer2 control system is totally separate to the controls for the other heat sources.


The LaZer2 system functions automatically without user input. The control system monitors the collector and calorifier/cylinder temperatures and starts the pump when there is useful solar energy to be gained. When there is no more useful solar energy available the controller stops the circulating pump.

The safety features incorporated into every system will ensure that the system temperatures can never get too high and that all components are protected against freezing.

System Design & Specification

The key to installing the correct solar thermal system is to ensure that the design requirements are fully understood and that consideration is made for other systems and controls. We work with all parties to ensure that the proposed solution is the most suitable for the application.

We offer a full design, specification supply and installation service and can provide a fixed cost quote for any solution.


We can supply and install the entire system; just install key parts, test and commission; or supply complete kits for installation by others.

To minimise costs and ease programming we will work with client and contractors to assess which parts of an installation can be completed by others.

Lead times for installation vary depend on the size of the system. We typically book engineers from 4 to 12-weeks in advance.


We stand by our solutions and are therefore always happy to deal with any questions or queries you or the client may have.

Every system we install is covered by a 2-year parts and labour warranty. The solar collectors are covered by a 25-year warranty against loss of vacuum.

There is no scheduled maintenance required for the first 5-years of a systems operating life. After 5-years we recommend that the heat transfer solution is checked and, if necessary, replaced.

We recommend that systems are visually checked 3-months after commissioning, 12-months after commissioning and the annually there after. We offer inspection and maintenance contracts if required.


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