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SAP 2012 Changes – Solar Heating

SAP2012 was unveiled under a cloak of darkness and without fanfare at the start of June. Until Part L is confirmed and released in England and Wales (and the updated Section 6 in Scotland), the SAP methodology will not be used, so we’ve got a few months to understand what’s changed, and how that may impact next year’s building projects.

Over this series of blogs, we’ll look at SAP2012 in detail:

The new SAP assessment will include several new features that impact the savings shown from solar thermal panels. The new measures are designed to give more accurate results, and should mean a typical house, particularly in the southern half of the country, will benefit more under the upcoming regulations than the current ones.

Some of the key changes include:

Geographical data: As covered in other blogs, the new SAP will introduce regional data for sunlight radiation and typical monthly temperatures. This means a house in a warmer, sunnier part of the UK will see a greater benefit from solar than those in the north

Panel location: As with before, the most beneficial position for a solar panel is due south with a 30 degree inclination. Currently the SAP assessor can select between the eight usual orientations (north, north east, east etc) and five pitches (horizontal, 30 degrees, 45 degrees etc).

For the upcoming set of regulations there will be more accuracy within the SAP, meaning it will be possible to model the solar panels at any degree of pitch and at any orientation.

Solar water use: A new factor, which considers if the solar-heated water is to be used in electric showers or not is being introduced. You’ll see a greater benefit if the showers in your dwelling are supplied direct from your boiler. Electric showers do not receive as much of a benefit from solar panels because they operate instantaneously.

Solar pumps: In SAP, solar panels are assumed to require a pump to circulate the hot water around the system. The energy used by this pump is fixed in the software. In SAP 2012, the assumed amount of energy used by this pump is dropping by a third to reflect the higher efficiency systems which are now available. SAP will show further improvements if the array has a passive or PV-operated pump.

Other factors which may impact the efficiency of a solar thermal system, such as overshadowing, assumed efficiencies and assumed heat losses remain unaffected going forward.

For regular updates on Part L 2013 and building regulations follow us on Twitter @EnergistUK

Jon Ponting

Author: Jon Ponting

This article was published by Jon Ponting on 03.07.2013.