Passive energy-efficiency in buildings

by Darren
Passive energy

BASF and CSIR conclude initial study on passive energy-efficiency in buildings. A breakthrough experiment demonstrates the efficiency of a highly insulated building with regard to indoor comfort and reduced heating and cooling loads.


New data will support specifiers and architects when determining their insulation requirements.

The Council for Scientific and Industrial Research (CSIR), in conjunction with BASF, undertook an energy and thermal performance research project in 2011 and 2012 on a house constructed on the CSIR Innovation Site in Pretoria, using BASF materials. Helm Construction erected the house using the Imison Walling System 3, which is certified by Agrément.

The study analysed the energy and thermal performance of a highly insulated demonstration house (the BASF House) through actual data collection and thermal modelling. Temperature data collection took place between December 2011 and April 2013.

The research entailed measuring actual temperature readings inside the house, and to model the energy and thermal performance with a view to establishing the thermal comfort and energy-efficiency of a highly insulated building system.

The results indicate that the BASF House will require minimal heating in winter to maintain a comfortable indoor environment. Using the conversion rate of 1Gigajoule (Gj) equalling 277,77 kilowatts hour (kWh)   and a kWh rate of R1,20, the BASF House will have an annual heating cost of R567.

For comparative purposes, the standard low-income house constructed on the CSIR Innovation Site has a heating load of 12,28Gj  or 3 401kWh with an annual heating cost of R4 082, while a South African National Standards 204 (SANS) compliant house has a heating load of 7,66Gj  or 2,127kWh and an annual heating cost of R2 553.
As can be expected from a highly insulted building, in summer the house will require cooling, but this can be achieved by opening windows and doors to allow natural ventilation.

The experiment demonstrates the efficiency of a highly insulated building with regard to indoor comfort and the reduction of heating and cooling loads. However, the placement of insulation and effective ventilation is critical in terms of maximising these efficiencies. The optimal performance will be achieved through:
a) Installing a roof with high reflective paint.
b) Placing 100mm insulation on top of the ceiling.
c) Ensuring that the insulation is tightly fitted to avoid thermal bridging.
d) Ensuring effective ventilation to the rooms for the summer period.
e) Ventilating the attic.

“Space heating costs can be significantly reduced in a residential building such as this: An owner of a small house could save close to 80% in heating per year as opposed to the SANS-compliant household, and this inevitably contributes to a healthier environment if we consider other forms of heating,” says Llewellyn van Wyk, principal researcher at the CSIR Built Environment Unit, under whose direction the experiment was conducted.

The aim was to measure absolute temperature performance of a standard building consisting of a roof, floor and walls using an alternative insulation technology based on Neopor®, a thermal insulation material by BASF. The house was also fitted with double-glazed windows and doors. “We expect this valuable data will support specifiers and architects when determining insulation requirements in the Pretoria central region,” Van Wyk added.

“BASF engaged in this study with the CSIR Built Environment Unit to demonstrate the need for insulation in maintaining comfortable living temperatures. Although this test case was aimed at measuring the effectiveness of Neopor® in the Southern Hemisphere, Cool Pigments for Paints also contributed to findings at the demonstration house. Apart from these two products, BASF also has other energy-efficient solutions for the building industry, for example, Elastopor and Micronal Phase Change Material, which enhance the local drive towards energy-efficient buildings,” says Dr Dieter Kovar, managing director of BASF Holdings South Africa.

Insulation material for energy-efficient applications
Neopor®, an expandable graphite impregnated polystyrene, is BASF’s forward-looking solution to improve insulation in newly built and renovated properties. It contains special graphite particles that reflect heat radiation like a mirror and thus reduce heat loss in a house. The granular material is processed by BASF’s customers and converted to insulating boards and moulded parts for insulating facades, roofs and floors. Insulating materials made of Neopor® can meet the standards for passive house construction and in warm climatic zones also save at least 30% of cooling energy for residential buildings.

Cool paints
Rising energy costs, pronounced urban heat-island effects and global warming increase the need for intelligent solar heat management solutions like cool coatings. BASF’s Innovative Paint it Cool Pigments for “green” coatings cause less absorption of solar radiation, leading to lower surface temperatures and reduced heat build-up. Therefore the energy demand for air-conditioning systems can be decreased significantly. A longer lifetime of coatings and substrate materials can be achieved.
The lead-free pigments in their portfolio are less harmful to the environment – lead chromates and molybdates have for many years been the backbone of yellow and red colours in the coating industry. These pigments have an excellent price performance ratio due to their good durability, opacity and colour strength. However, with the inclusion of lead chromates on the Annex XIV under REACH, production and use of these pigments will be banned in Europe from May 2015. BASF has a broad organic and inorganic pigment portfolio providing sustainable lead-free pigments to formulate lead-free coatings.
BASF Holdings South Africa
Petra Bezuidenhout
Head of Communications
Tel: (011) 203 2400
Website: www.construction.basf.com
Local website: www.basf.co.za

You may also like