Specifying A Solar Thermal Water Heating System

When we design a solar water heating system there are a number of important factors to be considered including orientation, demand and existing heating system.

Orientation of Solar Thermal Panels

• The most effective orientation for a collector (in the UK) is facing due south. Efficiency falls off progressively from collectors facing towards east or west – though practically, even if a collector faces either due east or west, this might be only around 80% of maximum efficiency.

• Lower efficiency from less-than optimum orientation can be matched by increasing the size of the collector.
• If a pitched roof faces east and west, consider mounting panels on both pitches. Collector controls can be programmed to favour the better performing panel as the sun tracks around the house to the south.
• The most common area to locate a collector will be on the main roof of the building.
• If for reasons of orientation or unsuitability of retrofit on the main roof, consider subsidiary roofs such as an extension. Even flat roofs can accommodate solar collectors through the use of proprietary framework.
• Care should be taken to avoid shading by eg chimneys, dormers, adjacent buildings, trees etc.

Sizing A Solar Thermal Water Heating System

A typical household solar collector will be around 4m2, we normally calculate the size required based upon likely demand. Sizing is important – if the area is too small there will not be enough heat in the hot water cylinder at a useable temperature, If the area is too large, energy will be wasted.

This aspect of the system is something our heating engineers will discuss with you during the site inspection to ensure that the system is the right size for the amount of water required in the household.

Existing Water Heating System

A critical part of designing and specifiying any solar water heating system on a property is understanding the current system in place and how to integrate the new heating method to get the most out of it. This is something which is assessed by our system designers and heating engineers during the intial site visit or telephone converation.

Solar thermal can be integrated into most existing heating systems, however there will always be a requirement for a water storage / heating cylinder in the property. Houses with combi boilers often do not have the space for a cylinder and therefore may not be suitable for solar thermal water heating..

If you can't see the information you are looking for or have aproject you would like to discuss please feel free to contact us. We have an experienced team who are happy to help.