Aerogel Insulation Advances
Nicknamed “frozen smoke,” aerogel is extremely lightweight material, with a density only 3 times that of air. Only a small fraction of a volume of aerogel is the material itself. Most of the volume is filled with air. This makes aerogel an excellent insulator. (Aerogel provides nearly 40 times the insulation of fiberglass insulation.)
Aerogel can withstand great pressures and is also an excellent sound insulator. Aerogels can also be used to absorb airborne pollutants and have been used to clean up oil spills. NASA also used a section of aerogel as part of its Stardust probe to collect samples of material from the tail of a comet.
Aerogel is available for some high-performance applications, but due to its high cost, it has not been widely used. However, new research from a Malaysian scientist offers the potential to drastically reduce the cost of producing aerogel, and could lead to new possibilities for its use as a building and insulation material.
Dr. Halimaton Hamdan from the Universiti Teknologi in Malaysia has developed a method of producing aerogel that could reduce the cost of producing aerogel by 80% by using agricultural waste from rice husks as the feedstock. Rice husks evidently have a high silica content, and silica is the main constituent of aerogel. In addition to potentially being able to produce aerogel for one-fifth the current cost, this also addresses a problem with disposing of rice husk waste.
Because aerogel is translucent, rather than completely transparent, one of the places it has first been used in architectural applications has been in daylighting panels. Commercial applications of aerogel are from companies such as Kalwall and Advanced Glazings, both of which produce diffuse lighting windows that incorporate aerogel to produce panels that transmit light while having an insulation R-value equal or better than that in an insulated wall in a new home. These windows aren’t for vision, but they allow a high percentage of light to be transmitted, allowing for diffused daylighting, which is a better method for lighting without producing unnecessary glare. However, until now, these windows have been used only in special instances because of their high cost.
If prices for aerogel become significantly lower, it should be possible to see highly insulating panels that can replace traditional forms of insulation. Even more compelling is the possibility for retrofitting existing buildings with relatively thin panels that can significantly improve their thermal performance. Since buildings last for such a long period of time, retrofit solutions are going to become an important part of reducing the amount of energy used by buildings without needing to demolish and replace everything that has already been built.
Links:
Green Building Elements: Super Insulating Vacuum Glass
Green Building Elements: Better Daylighting
NASA: Aerogel fact sheet
Image Source: NASA via Wikipedia
via: EcoGeek
FYI Advanced Glazings has closed down.
ERV Energy Recovery Ventilation Systems Reduce Long Term Costs and Improve Indoor Air Quality
Is the indoor air your breathe is as fresh and healthy as it can be?
As building science professionals have known for some time, an effective ventilation strategy is an absolute requirement for all homes. Mechanical ventilators exchange air inside the home with fresh air from the outside. This helps to reduce indoor pollution levels, and greatly increases the comfort level inside the home.
Many ventilation designs are including Energy Recovery Ventilators (ERVs) to improve the system efficiency. Besides providing controlled ventilation, ERVs are able to filter, humidify, dehumidify, heat, or cool the incoming fresh air. The most popular design of ERVs utilizes a desiccant wheel to remove both heat and a significant amount of moisture from the incoming air, which reduces the load on the air-conditioning system. But while ventilators and ERVs can add tremendously to the comfort and efficiency of a home, they must be installed correctly.
One of the more recent developments in the ‘green’ technology industry is the creation of environmentally-friendly buildings that use energy-efficient technologies to reduce power consumption.
Energy consultants point out that creating ‘green’ buildings and improving the air quality inside such facilities utilizing ERV can and do go hand-in-hand. ERV Systems that reduce demand for energy while improving ventilation are increasingly in demand.
ERV – Energy Recovery Ventilation systems saves energy, increases indoor air quality, reduces contaminates and odors.
The use of ERV technology “energy recovery ventilation systems,” or ERVs. Such systems are designed to reduce energy consumption and improve indoor air quality (IAQ) by capturing and recycling building energy to humidify, pre-cool or dehumidify incoming air.
ERVs, the research first said, are most popular in areas with more extreme outdoor temperatures, like Northern states where winters can get quite cold, or Southern states where very warm temperatures and high humidity demand more energy consumption to maintain comfortable indoor environments.
“The focus on IAQ is another key trend benefiting ERV, as people become increasingly conscious of the importance to maintain air quality through properly designed and managed HVAC systems,” Energy consultant said in the energy audit survey.
Market growth for ERVs, Energy consultant said, is driven largely by energy conservation policies that are challenging building custodians to reduce energy consumption for indoor climates. The firm cited as an example the 90.1 standard from American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) which currently dictates “energy recovery systems for applications of 5000 cubic feet per minute (cfm) and larger with 70 percent outside air (OA).”
ASHRAE 90.1 is a standard that specifies at least 50 percent total effectiveness for ERVs, Energy consultant said.
The Air Conditioning and Refrigeration Institute and the U.S. Environmental Protection Agency also have various standards and regulations regarding energy recovery and IAQ.
Energy Consultant said two main obstacles lie in the way of more widespread use of ERVs: lack of knowledge and the need to reduce operating costs in the short term. Since building owners and facility managers rely for the most part on contractors to select and install heating, ventilation and air-conditioning (HVAC) equipment, if the contractors are not up-to-speed on ERV developments they may pick products that aren’t as energy-efficient as they could be.
Also, Energy consultant noted, HVAC contractors work within budgets and therefore tend to buy equipment based on its price rather than long-term cost benefits. It therefore is important to educate contractors about ERVs, and some of that burden falls on manufacturers. The Green Building Council is also playing a role through its Leadership in Energy and Environmental Design program that evaluates buildings to determine the environmental performance during their entire lifecycle.
ERVs aren’t just good for the planet; they’re good for people, too.
“The focus on IAQ is another key trend benefiting ERV, as people become increasingly conscious of the importance to maintain air quality through properly designed and managed HVAC systems,” Energy consultant said in the report.
When IAQ isn’t managed properly, people living or working in unhealthy buildings can develop sick building syndrome from pollutants in the air they breathe.
“With half of all illnesses attributed to indoor airborne contaminants, the U.S. Environmental Protection Agency (EPA) has declared IAQ a public health priority,” Energy consultant said. “Ventilation with outdoor air is the only strategy that can simultaneously reduce the levels of all indoor pollutants.”
Compiled by: Jay Draiman, Energy analyst – Northridge, CA
You can purchase aerogel insulation for less than $5/square foot from Aspen Aerogels today. Go to http://www.aerogel.com.