Additional Salient Features of Efficient Building

Solar Cooling

Solar cooling refers to applying solar energy to drive a cooling process. The solar energy-supported acclimatization represents an innovative climate control system. The primary advantage is that the solar thermal energy facility generates the maximum quantity of energy during the summer months when the demand for cooling is at its peak. In winter, the energy stored in the solar thermal collectors is supplied to a buffer energy storage unit to support the heating system. So the solar cooling system obtains a reduction of energy use of 50% to conventional office buildings.

Intelligent Lighting

The layout of the building and the facade concept could easily make it possible to supply the entire building with daylight, which helps minimize the need for artificial light. In comparison, conventional offices require 40% artificial lighting. In addition to these measures, special light-directing blinds also channel daylight into the depths of the rooms, which in turn ensures more room brightness.

Green Ventilation 

Plants may be integrated into the office complex as a so-called green buffer zone.   During the winter months,  they ensure a particularly pleasant room climate through the ecological, controlled humidification of the air being supplied.   For example, Cyprus grass-type plants are specially bred for humidification purposes that help humidify the air in winter and during transition

periods between seasons. They function as closed moisture-generating systems, which, for the first time, can be, integrated as adjustable, precisely controlled, and calculable units into building engineering systems.

Geothermal Heating and Cooling Systems 

In large buildings, many individual heat pumps can be placed in different zones, and each can be sized to meet the needs of the space it conditions. When properly integrated, these systems recover excess heat from one indoor zone of the building and use it where it is needed. For example, heat pumps on the sunny side of a large building with an integrated system can provide cooling while those on the shady side are providing heat. Each of these individual units is attached to the same earth connection by a loop inside the building. It is even possible to connect multiple buildings in the same general area to the same earth connection. If one of the heat pumps in a multi-pump installation does need servicing or replacement, the problem is easily isolated and corrected because of the modular nature of the equipment. The rest of the heating and cooling system is not affected.

GHPs also save money in large buildings with multiple heat pumps by reducing the amount of space required for mechanical rooms.  GHP   systems use smaller ducts because the air handling system only provides make-up air and does not carry heat. This results in smaller floor-to-floor heights as heating and cooling BTUs are transferred via small pipes rather than bulky ducting. By eliminating roof-mounted equipment, the roof lasts longer and the structural steel can be downsized. In large commercial installations, the initial costs of GHPs are very competitive with boilers and cooling towers.

All these economies add up to a handsome return on investment for businesses that choose GHPs. If the initial cost of installing a GHP system is higher, these systems typically pay for themselves in reduced energy and maintenance costs in less than five years.

Geothermal heating system price varies depending on the type of loop system, usually either vertical or horizontal. On average, a typical home of 2500 square feet, with a heating load of 60,000 BTU and a cooling load of 60,000 BTU will cost $20000 - $25000 to install.34 This is around double the cost of a conventional heating, cooling, and hot water system, but geothermal heating/cooling systems can reduce utility bills by 40% to 60%. The payback for a system can range from 2-10 years, while the lifetime of a system can be 18-23 years, almost double a conventional system. We recommend that there should be tax rebates for energy efficiency improvements, including a 30% central tax credit, and many state and utility incentives.

Building Integrated Photovoltaic Panels (BIPV)

Today, thousands of people power their homes and businesses with individual solar PV systems. Utility companies are also using PV technology for large power stations. Solar panels used to power homes and businesses are typically made from solar cells combined into modules that hold about 40 cells. A typical home will use about 10 to 20 solar panels to power the home. The panels are mounted at a fixed angle facing south, or they can be mounted on a tracking device that follows the sun, allowing them to capture the most sunlight. Many solar panels combined together to create one system is called a solar array.   For large electric utility or industrial applications, hundreds of solar arrays are interconnected to form a large utility-scale PV system. Traditional solar cells are made from silicon, are usually flat-plate, and generally are the most efficient. Second-generation solar cells are called thin-film solar cells because they are made from amorphous silicon or non-silicon materials such as cadmium telluride. Thin film solar cells use layers of semiconductor materials only a few micrometers thick. Because of their flexibility, thin film solar cells can double as rooftop shingles and tiles, building facades, or the glazing for skylights.

Third-generation solar cells are being made from a variety of new materials besides silicon, including solar inks using conventional printing press technologies, solar dyes, and conductive plastics. Some new solar cells use plastic lenses or mirrors to concentrate sunlight onto a very small piece of high-efficiency PV material. The PV material is more expensive, but because so little is needed, these systems are becoming cost-effective for use by utilities and industry. However, because the lenses must be pointed at the sun, the use of concentrating collectors should be limited to the sunniest parts of the country.

Low-Emissivity Window Glazing

Low-emissivity (Low-E) coatings on glazing or glass control heat transfer through windows with insulated glazing. Windows manufactured with Low-E coatings typically cost about 10%–15% more than regular windows, but they reduce energy loss by as much as 30%–50%.

A Low-E coating is a microscopically thin, virtually invisible, metal or metallic oxide layer deposited directly on the surface of one or more of the panes of glass. The Low-E coating reduces the infrared radiation from a warm pane of glass to a cooler pane, thereby lowering the U-factor of the window. Different types of Low-E coatings have been designed to allow for high solar gain, moderate solar gain, or low solar gain. A Low-E coating can also reduce a window's visible transmittance unless you use one that's spectrally selective.

To keep the sun's heat out of the house (for hot climates, east and west-facing windows, and unshaded south-facing windows), the Low-E coating should be applied to the outside pane of glass. If the windows are designed to provide heat energy in the winter and keep heat inside the house (typical of cold climates) then the Low-E coating should be applied to the inside pane of glass.

Window manufacturers apply Low-E coatings in either soft or hard coats. Soft Low-E coatings degrade when exposed to air and moisture, are easily damaged, and have a limited shelf life. Therefore, manufacturers carefully apply them in insulated multiple-pane windows. Hard Low-E coatings, on the other hand, are more durable and can be used in add-on (retrofit) applications. The energy performance of hard-coat, Low-E films is slightly poorer than that of soft-coat films.

Although Low-E coatings are usually applied during manufacturing, some are available for do-it-yourselfers. These films are inexpensive compared to total window replacements, last 10–15 years without peeling, save energy, reduce fabric fading, and increase comfort.