reflective white roof more effective than lawn for greening existing buildings by John A. Herbert

Commonsense really…..

reflectA reflective white roof is more effective than lawn for greening existing buildings, here is a link to my article published on LinkedIn https://t.co/H8SyyavhHU

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Design vs Performance

Building regulations, Energy codes, and like tend to specify a performance parameters for the design stage, not actual building performance. The building code requires a certain OTTV  (Overall Thermal Transmittance Value) defined by w/sqm, for the building envelope. However, the delivered performance is never measured.

The energy code also requires air conditioning chillers to meet certain catalogue performance targets, however the nominal capacity is tested at steady state standard ARI conditions, unlike real life which suffers hourly variations.

zcb_45_600w

Hong Kong’s Nett Zero Energy building, known locally as the Zero Carbon Building or ZCB has a display which clearly shows (recorded 17 October 2013)  the energy consumption (277,597 kwh) exceeds the energy generated (183,470 kwh). therefore the ZCB has only provided 66% of the total energy demand, and we must assume that no energy exported to the grid.

zcb_46_600w

ABOVE: Watering the lawn at Hong Kong’s ZCB is a low technology affair (17 Oct. 2013)

Setting design performance goal is admirable, but that is only one aspect of building performance, and don’t expect design parameters alone to create high performance, low carbon buildings.

zero carbon building hong kong

ABOVE: ZCB, noon, buildings shadows the PV panels.

Actual data, for example the BEEO Cap 610 demands that every commercial building post EMSD form EE5, that provides facts, and for the first time allows comparison between performance of similar building types.