Enviropundit: Green Building Blog

Archives: LEED (Leadership in Energy and Environmental Design)



Monday, November 21, 2005

Top 10 Building Products

BuildingGreen has announced the top 10 building products that have been included this year into the GreenSpec Product Directory. I found two to be especially intriguing.

UltimateAir RecoupAerator 200-DX ERV from Stirling Technology
An energy recovery ventilator (ERV) crosses two streams of air: air leaving the house with air coming into a house. The stale air exchanges some heat with the fresh air, which lowers the heating or cooling load of the main unit. This ERV has a 95% transfer efficiency. Additionally, this unit filters incoming air through a washable MERV 8 (98% of allergens and pollutants) filter as it passes through.


Ice Bear Thermal Energy Storage System from Ice Energy
Thermal energy storage (TES) is a cooling technology through which cooling capacity is generated at night using off-peak electricity to chill water or make ice; then that chilled water or ice is used during the daytime to cool a building. This was primarily used by large buildings to lower energy costs through using lower rates and, secondarily, to save energy through having chillers run at 100% capacity without cycling on and off, which is their most efficient mode. These systems included chillers and storage tanks, and sometimes cooling towers, depending on the type of chiller used.

This unit is designed for homes and smaller applications can use multiple units to cover their loads. This system consists of a standard outdoor condensing unit, an indoor 5'x5' storage unit and evaporator and fan (standard inside unit). At night, the condenser makes ice from tap water inside the storage unit. During the day, a pump sends the melted water through the evaporator. This provides a 95% reduction in peak demand and can be more efficient than normal cooling units depending on the climate. It also can be a higher efficiency for the same reasons as the larger unit: it doesn't cycle on and off and can run at 100% capacity.

Currently, this would be advantageous to those electricity customers that have two rates, one for peak loads and one for off-peak loads. In Maryland, we have one rate for both, so this won't help us too much. Another scenario where it would be helpful is in a distributed grid [I know: big surprise ;)]. This can be one option for energy storage for homes and small businesses that act as power producers. It can also help advance zero net energy homes with storage. The choice of storage for either home or grid, whether it is in the form of heat, cooling or energy, should depend on the specific location where storage is needed. Each location will have different design criteria, such as climate and rate structures, that will impact the choice.


The rest of the Top 10 are: