Peak power and cooling energy savings of shade trees

Abstract

In summer of 1992, we monitored peak power and cooling energy savings from shade trees in two houses in Sacramento, CA. The collected data include airconditioning electricity use, indoor and outdoor dry bulb temperatures and humidities, roof and ceiling surface temperatures, inside and outside wall temperatures, insolation, and wind speed and direction. Shade trees at the two monitored houses yielded seasonal cooling energy savings of 30%, corresponding to an average daily savings of 3.6 and 4.8 kWh/ d. Peak demand savings for the same houses were 0.6 and 0.8 kW (about 27% savings in one house and 42% in the other). The monitored houses were modeled with the DOE-2.1E simulation program. The simulation results underestimated the cooling energy savings and peak power reductions by as much as twofold.

The impact of greening systems on building energy performance: A literature review

“…For two monitored houses in Sacramenta, Akbari et al [58] simulated the energy saving for summer cooling by around 30% through shading the southern and western facing walls by sixteen trees. Simulation results by Simpson & McPherson [59], shows energy savings up to 50% for cooling when shading trees are located in all directions except north in the mediterranean climate of California.…”

Identifying Scope for Future Research on Urban Greening in India-AComparative Perspective with Global Greening Initiatives

“…Tree shade reduced residential cooling energy savings in Sacramento, USA by 30% (12). A decrease of 72% was estimated in the cooling energy demand in Mumbai after greening of roofs and walls (13).…”

Energy Efficient Landscape for Thermal Comfort in Buildings and Built-up Areas

“…For The surface temperature reductions are ranging from 11-25 º C for walls and roofs at two buildings. A detailed study had been conducted to examine the effects of vines on wall temperatures and found reductions up to 20 ºC as in [24] . Further, it was emphasized and found that tree shading reduces the temperatures inside parked cars by about 25 ºC as mentioned in [25].…”