Sustainable Building Articles

Azlan prides itself on assisting clients to “think green”.  We enjoy educating and promoting sustainable building practices. Utilizing the latest in geothermal, solar and other home building materials will reduce our carbon footprint and will prove itself to be cost-effective for commercial and residential buildings.  The following article is a first in a series on “green” building technology.  The first is focus on geothermal heating….

Geothermal (ground-source) Heat Pumps

What are Geothermal heat pumps?
Geothermal (ground-source) heat pumps (GSHP)  are one of the best ways to build green.  It is one of the best uses of renewable energy in the world, with annual increases of 10% in about 30 countries over the past 10 years. Its main advantage is that it uses normal ground or groundwater temperatures (between about 5 and 30oC).

The United States and Europe have been the biggest proponents of this sustainable energy source.  Countries like Austia, Germany, Switzerland, and Sweden lead the way in green building. A fairly simple design, GSHPs use the relatively constant temperature of the earth to provide heating, cooling and domestic hot water for homes, schools, government and commercial buildings.  The technology isn’t new, as Lord Kelvin developed the concept in 1852.

GSHPs come in two basic configurations: groundcoupled (closed loop) and groundwater (open loop) systems, which are installed horizontally and vertically, or in wells and lakes. The most popular is the ground-coupled system, a closed loop of pipe, placed either horizontally (1 to 2 m deep) or vertically (50 to 100 m deep), is placed in the ground and a water-antifreeze solution is circulated through the plastic pipes to either collect heat from the ground in the winter or reject heat to the ground in the summer . The open loop system uses groundwater or lake water directly in the heat exchanger and then discharges it into another well, into a stream or lake, or on the ground (say for irrigation), depending upon local laws.

UPSIDES -Qualifies for “building green” -Sustainable, environmentally clean -High return on investment, as much as 60% energy savings every month -Low maintenance cost.

DOWNSIDES -Higher upfront cost -In high heat regions, extra electric pumps may be needed to pull heat from home.

Practical Example: One of the largest examples of  GSHP installations in the United States is at the Galt House East Hotel in Louisville, Kentucky. Heat and air conditioning is provided by GSHPs for 600 hotel rooms, 100 apartments, and 89,000 square meters of office space for a total area of 161,650 square meters.  The energy consumed is approximately 53% of an adjacent similar non- GHP building, saving $25,000 per month.