Eco-Friendly Cooling Equipment is Coming

Mechanical Cooling Needs to Use Less Energy and Avoid Dangerous Refrigerants

Heat waves are becoming more frequent, more extreme, and more widespread. Air-conditioning (AC) is ubiquitous in the U.S. (90 percent penetration), but not in Europe and many other regions where it is increasingly becoming a necessity. Outside the U.S., less than 25 percent of people in regions that merit AC have it. Consequently, the International Energy Agency expects AC energy consumption to triple worldwide by 2050.

Unfortunately, AC, in its current form, carries significant environmental costs: More demand for cooling leads to more warming of the planet. In addition, the refrigerants used in cooling condensers are 2,000-3,000 times more potent than carbon dioxide as a climate-warming agent when it leaks into the atmosphere.

Gradient Comfort, a San Francisco–based company, is tackling AC’s climate predicament — their mission is to push the industry to zero carbon emissions. Gradient has developed an innovative window cooling and heating unit that is both efficient and eco-friendly. It is a heat pump, a technology gaining in popularity for centralized heating and cooling systems because of energy efficiency, but such equipment tends to be bulky, expensive, and requires professionals to install. Gradient’s technology, however, offers a sleek, affordable, and compact alternative. 

The only Gradient model currently available (it only came on the market this summer) is a window unit. It sells for $2,000 compared to $5,000 or more for comparable units. Their saddle bracket fits on the windowsill of a single- or double-hung window and holds a sleek, attractive fan-coil unit on the inside while the evaporator heat pump is on the outside. Both components fit below the window, so that views are not obstructed. Housed with the fan coil is a quiet fan, eliminating any noise issues. The company is designing other models to fit other styles of windows, e.g., casement units. The unit is planned for do-it-yourself installation in 15 minutes with just a few basic tools. 

Gradient won the Fast Company’s 2022 World-Changing Ideas Award. The cooling component is 30 percent more efficient than traditional window units. When both heating and cooling are combined, the improved efficiency jumps to 75 percent. Another big plus is the refrigerant: Although still a hydrofluorocarbon, the fluid used by Gradient has a quarter the global warming potential of those used by other AC manufactures. They are working to improve their refrigerant even more.

The Gradient device is designed to use only the amount of energy required as it is turned up or down. It is also linked to Wi-Fi in order that it can be self-adjusted when there is heavy demand on the electric grid.

Although Gradient needs more improvements to reach its goal of zero greenhouse-gas emissions, it has taken big first steps in addressing the widespread flaws in existing systems: high cost, cumbersome installations, and unsightliness. These are important directions for widespread adoption of cooling including in less affluent areas of the world.

Breakthrough Envelope Sealing

Leaky homes are harder to heat and cool and can account for higher energy bills and reduced air quality. Recently, air sealing has become an essential element in zero net energy homes. 

Modified Blower Door

Air leakage in a typical home, as measured with a blower door test, might have an air leakage rate of 4.0 to 5.0 air changes per hour at 50 Pascals (ACH50). Most zero energy homes now push the leakage rate to 1.0 or 2.0, while Passive House requires a maximum leakage of 0.6 ACH50.

Recently, the Allen team worked with our client and Western AeroBarrier to seal a home and achieve an ACH50 of .47.

Automated sprayers disseminate a fog of sealant inside the building

Results are monitored in real time

AeroBarrier technology, using a GreenGuard Gold Certified, non-toxic, water-based sealant, finds and fills gaps in the building envelope as small as a human hair and up to .5 inches in just a few hours. The process uses a modified blower door to pressurize the building and automated sprayers to disseminate a fog of sealant inside.

As the air is forced out through the cracks and gaps in the building envelope, the sealant travels along with it, accumulating on the edges of the openings, and eventually fills in all the gaps. This process can be monitored in real time and can achieve a specific level of air tightness to meet energy performance goals. In this case, the homeowner wanted to achieve an ACH50 of less than .5.

After prepping the 4,000 square foot home by taping off the doors and windows, the process took about 3.5 hours to go from an ACH50 of greater than 5.0 to surpass the goal ending at .47, an impressive 91.2% reduction in envelope leakage.

Benefits of Envelope Sealing:

·      Improved Indoor Air Quality

·      Improve System Performance

·      Improve Home Comfort

·      Lower Energy Bills

Sustainable Flooring Options

What properties, besides cost, warrant consideration when considering flooring choices? Health issues such as toxicity or the avoidance of bacteria, dust and allergens need foremost attention. Health concerns should disqualify carpeting. Although there are eco-friendly choices for carpeting, such as wool, sisal, P.E.T. Berber (made from recycled plastic bottles) and carpet tiles, none of these avoid the inherent problem with all carpeting: the trapping of dirt, mites, pesticides and chemicals tracked in from outside. The AIA (American Institute of Architects) did a study some years ago, weighing newly installed carpeting that was steam cleaned weekly over its 10-year life and weighing it again when pulled up. Despite the rigorous cleaning schedule, it weighed 3 times its original weight. No cleaning method can completely remove the dirt and bacteria that get ground into carpeting.

If we rule out carpeting, what are other good choices? Wood flooring is one. Durability, recycled, reclaimed or renewable material, and transportation distance are key criteria for environmentally-friendly flooring. Taking these measures into account, wood flooring rates high. Solid wood flooring is not usually considered sustainable due to deforestation concerns, but wood from forests that are responsibly and sustainably managed and that carry the FSC (Forest Stewardship Council) certification guarantee negate any such worry. Reclaimed wood milled into flooring or, even better, reclaimed wood flooring is another way to get attractive flooring without logging existing forests. Then there is pre-finished, engineered wood flooring (FSC certified). Engineered wood is more stable than sawn boards, uses less wood per square foot, and avoids off-gassing when toxic-free adhesives are used. 

Although frequently considered along with wood flooring, bamboo is actually a rapidly growing grass and thus supremely renewable. Make certain the bamboo is mature, 4-6-year growth, because flooring made from 2-3-year-old bamboo is soft and scuffable. A variation, strand woven bamboo, has more of a wood grain look, is stable and extremely hard—twice as hard as oak. The only drawback to bamboo is that most of it comes from China, requiring transportation half way around the world.

Concrete isn’t usually thought of as sustainable or as flooring. When made with a high percentage fly-ash mix, concrete becomes considerably greener. Fly-ash is a waste product from coal power plants that can be substituted for cement and greatly reduces its greenhouse gas emissions. Concrete slabs can be turned into beautiful, eco-friendly flooring through selection of score pattern, use of organic dyes and careful polishing—often being made to look like stone, tile or old leather. As finish flooring, it saves the expense and material needed to install another finish floor over it. Concrete flooring contributes to high-quality, indoor air.

Other sustainable flooring choices are: naturally cushioned, anti-microbial, sound and thermal insulating cork (bark from cork oak trees); linoleum made from linseed oil, cork dust, tree resins and limestone; and glass tiles made from recycled glass bottles.

Flooring can be beautiful, easy on the environment and promoting of good health and there is a wide variety of choices.

Smart Windows Can Boost Energy Performance

Innovations in glazing technology have transformed window performance over the past three decades. Transparent glass panes can now darken in bright sunshine by means of thermochromic or photochromic films or coatings. When the temperature of the glass increases from the sun’s infrared rays, the transparency decreases, and the glass becomes clouded or frosted. With photochromic treatments, the glass occludes because of increased light intensity.

Window self-darkening coatings were adopted from eyeglass lenses that changed their tint in sunlight. These perpetually reversible rearrangements of molecules that respond to solar radiation yield big energy savings in a building’s air-conditioning demands, sometimes by as much as 25 percent. Air-conditioning accounts for about 6 percent of all electricity generated in the US, with its accompanying negative climate and health impacts.

Another similar window technology called electrochromic uses a small electric current to polarize coating crystals to create clear or frosted states. This type of glazing is sometimes called intelligent glass or switchable smart glass. It is often chosen for privacy requirements as well as for heating and glare protection.

The latest window research holds the promise of reducing a building’s cooling demand while also generating electricity. By placing a film of perovskites, a relatively new solar cell material, between two layers of glass, electricity is generated. These highly effective and inexpensive crystals are injected with a solvent vapor into the gap between the panes of glass. As temperatures rise, the vapor triggers a chemical reaction that rearranges the crystals into different shapes, increasingly opaque, while simultaneously generating electricity. This progressive blocking and subsequent tinting happen at temperatures ranging from 95 -115 degrees Fahrenheit and take only seven seconds to occur. Researchers predict a prototype window using this technology to be developed within a year.

Technological ideas to address climate change abound. Many are already making their way into the marketplace. Technological inventiveness can help us reduce carbon emissions, but to fundamentally reverse our destructive climate patterns, we need a different framework:

·         where resources are used carefully and in cyclical processes, following nature’s example,

·         where human growth takes precedence over consumerism and economic growth,

·         where equity and inclusivity are high priorities, and

·         where environmental restoration becomes an employment and societal benefit.

These and other similar tenets will restore the health of our earth and nurture its biodiversity.