Gulf Construction Online - EIFS holds key to energy savings

Insulation

EIFS holds key to energy savings

External insulation and finish systems (EIFS) can play a major role in optimising energy consumption especially in the hot, humid conditions prevalent in the Middle East, writes MAIS HADDADIN* of Terraco Technical Centre Middle East.

01 December 2005

With energy costs shooting up by the day, the need to save energy and natural resources has become mandatory and essential.

The rapid expansion in the constructional activities throughout the Gulf region, and the hot and humid climate, has made thermal insulation one of the most important energy saving aspects – where up to 40 per cent of the energy consumption for cooling can be saved.
According to statistics published by Dubai Electricity and Water Authority (Dewa) the peak electricity consumption load was almost 2,784 MW in the summer of 2003, compared to 2,442 MW in the year 2001. Power generation stood at 15,616 gWh for 2003 for 260,876 consumers when compared to 12,973 gWh for 240,855 consumers in 2001. It can be noticed that the energy consumed in Dubai alone has increased 20 per cent with an increase of 8 per cent in consumer numbers in all different sectors only in the past two years.

Uninsulated walls absorb a great deal of heat and hence large amounts of energy are lost as a result of this. Therefore, improvements in wall insulation will have substantial implications in terms of energy efficiency.
Utilising a thermal insulation system will not only ensure greater energy efficiency and economy but will also bring about a healthier environment because of the limited emission of environmentally-hazardous substances such as carbon dioxide (CO2) and other by-products typically associated with energy production. An average person will typically spend 70 to 75 per cent of his or her life in enclosed spaces. This makes the task of ensuring comfortable and healthy interior environments an important priority.

EIFS
External Insulation and Finish System (EIFS) – also referred to as Exterior Thermal Insulation Composite System (ETICS) – was developed in Europe in the 1950s after World War II and was introduced in the 1970s in the US (Table 1).
EIFS can be defined as wrapping the exterior surfaces of a building in an energy-efficient thermal blanket. The main purpose of external insulation systems on buildings is to provide integral insulation by insulating heat transfer elements in external elevations such as walls, columns, beams and sheer walls.

Benefits
There are various thermal insulation options in the market today. So what gives the EIFS the edge over other options?
Superior energy efficiency: EIFS literally wraps the exterior of a building in an energy-efficient thermal blanket, thereby reducing heat transmission (Table 2). This results in the stabilisation of the interior environment and a reduction in energy consumption.
Heat (which travels from hot to cold) flows outwards in cold climates and inwards in hot ones, which means that reducing the heat flow/transmission will decrease the energy consumption. EIFS can reduce heat transmission by reducing air infiltration by as much as 55 per cent compared to un-insulated standard brick or wood constructions.
Dubai Municipality regulations state that the U value should be less than (0.1 Btu/ f.ft.h) for the thermal insulation system to be approved.

Design flexibility
EIFS comes in a range of aesthetically-pleasing colours and a wide variety of textures, which allows the applied product to be fashioned into a virtually unlimited number of shapes and designs. With EIFS, skilled applicators can create all sorts of exterior architectural detailing that would often be cost-prohibitive using conventional construction and finishing techniques.

Superior resistance
EIFS outperforms other insulation options by maintaining its original appearance over time especially when using acrylic or silicon-based coatings that can withstand extreme climatic conditions. Since the colour is integral to the finish coat, even if the surface is scratched, the same colour will appear beneath the abrasion.

Building stresses
Due to its superior energy efficiency, a lower capacity air-conditioning equipment can be specified. Another advantage is its ability to limit the physical effects of temperature fluctuations on structures. In addition, buildings thermally insulated with EIFS tend to have less noise pollution.

Job site quality control
The following steps should be taken into consideration on all EIFS project sites to ensure a high quality professional installation of the system that will result in a long-term performance:
•  EIFS should be installed only by experienced applicators who have completed EIFS training or have been approved by the manufacturer.
•  Quality windows, sealants and kick out flashes should be used when building with EIFS. Sealing should be around windows, doors, roofs, deck-to-house attachments, and all other exterior wall penetrations to ensure that there is no intrusion of water behind the system.
•  Adhesive must not exceed edges of the insulation board and allowed to dry.
•  The length of fastener shall generally be defined as the sum of thickness of the insulation board + thickness of adhesive layer + depth of penetration to wall (minimum 4 cm)
•  Joints with wood constructions must be filled with acrylic mastic.
•  Periodic maintenance of the system should include thorough checking of the flashing and sealing to ensure that the building envelope remains watertight. Damaged or missing flashing should be repaired or replaced immediately; likewise, cracked or deteriorated sealants should immediately be repaired, or removed and replaced.

Conclusion
EIFS is applied worldwide on external walls of buildings not only to save energy costs from 30 per cent up to 70 per cent for heating and cooling systems, but also to provide a healthier and more comfortable living environment.
EIFS pay-back period is at once. Insulation produces savings directly by reducing the size of cooling equipment required, apart from the reduction in annual running costs.
The use of polystyrene insulation significantly reduces energy costs and enhances thermal comfort inside the building, as well as being financially feasible.
The applicator’s job-site quality control remains one the most important elements in producing a high quality professional installation.
These controls consist of proper substrate/surface preparation, using the correct ratio when mixing materials, applying material at correct film thickness, using correct tools and application techniques, adherence to job details, and monitoring weather conditions during application and curing.
In conclusion, this paper demonstrates the importance of wall insulation in different climate zones that will have substantial implications in terms of energy efficiency, economy and environmental impact.

Acknowledgments
The author of this paper expresses her appreciation to those who made contributions to this paper including: Muthafar Emeish of NERC, RSS-Jordan; Zeid Al Shawa of Wacker Dubai Technical Centre; John Carey of Terraco Technical Centre; Eric Widstrom of Terraco AB; Imad Abu Saleh of Terraco UAE; and staff at Terraco Jordan for their full support and the Terraco group represented by Goran Widstrom.

References
• National Energy Research Center, NERC, Royal Scientific Society, Amman-Jordan
• DEWA website: http://www.dewa.gov.ae/aboutus/electSats.asp
• Dubai Municipality website, http:/www.datadubai.com / dubaimet.htm
• EIFS Industry Members Association, EIMA, website: http://www.eima.com.
Simulation of Heating Systems in Jordanian Buildings, June 2000, thesis by Muthafar S Emeish, Royal Scientific Society

* This paper was presented by Mais Haddadin of Terraco Technical Centre Middle East at Gulf Construction Conference Week’s Annual Insulation Conference held in Dubai, in November last year.