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Sustainable Heating and Cooling: Digging The Foundations

By L.D. Gussin

Dec 28, 2009

Beginning to take conservation seriously, society is shocked by the data on energy waste. Nowhere is this truer than in the way we heat and cool dwellings.

For generations, back to electrification, our knowledge of home energy use was masked by dial thermostats that helped us to be comfortable but hid most of the cost. In recent years, programmable thermostats, conservation-minded but hard for most of us to use, have begun to replace the simple dial.

What this “comfort” thermostat has hidden from us is that buildings account for 40% of our energy use and HVAC (heating, cooling and ventilation) 56% of that, that the leaks in most buildings make their HVAC work harder, that HVAC systems themselves are energy hogs, and that most are badly installed or maintained, to the extent that duct leaks alone make them run on average 20% less efficiently in our dwellings than they do in manufacturer's tests.

Nor has the comfort thermostat taught us the environmental cost of our habits: that all our air conditioners running in tandem cause utilities to use their most CO2-laden energy sources, for example. Nor did it tell us that most utilities, until recently tasked only to deliver all the energy we want, were happy to facilitate this wastefulness.

Fortunately, in recent years some public and non-profit entities and some companies have gotten a start toward energy efficient HVAC. And these seeds are about to sprout — provided that the public will, translated into laws and public investments, can be brought along. But it isn't close to clear that efficiency politics well win (see Copenhagen). Our tragically high degree of heating, cooling and ventilation waste could ride a long plateau or even worsen.

Thus this energy efficiency story, like all others, is one of advocacy, technologies and consumers.

Faulty Towers

On Jan. 1, the programmable thermostat, used to tell an HVAC system when it can regularly reduce its load (for example, in the hours when a house is usually unoccupied), will lose its Energy Star ratings. Manufacturers will have to remove the Energy Star logos from their product boxes. EPA is forcing this change because research shows that most people can't figure out how to use them right.

Thus, 2010 begins with a big if temporary defeat, for mitigation advocates and for businesses. Absent the Energy Star logo, will these products that add extra cost find buyers?

HARDI, the HVAC distributors trade association, wrote to the EPA in November:

"Preventing the industry from providing an Energy Star labeled product for the most seen and recognized aspect of any HVAC system threatens to erode consumers’ perceived value of the multi-thousand dollar Energy Star HVAC system they just installed."

Which makes us ask what Energy Star HVAC systems are and how they came about. We again start with energy waste in the system, which as energy prices rise will be wasting money, as well. The inefficiencies begin upstream from HVAC, in the building envelope, in its insulation, windows, and doors. But this is a story in its own right.

Green building materials are being developed, “holistic” home energy auditing tactics are emerging, a $23 billion “Cash for Caulkers” program is being promoted by the Obama team, and the problems associated with fixing 110 million existing residential building envelopes, each built and maintained in idiosyncratic ways, are astounding.

The HVAC industry, manufacturers and a sales and services channel, has always accepted wasteful envelopes, as it accepted low energy costs, and it accepted its own role being to provide space comfort without regard to waste.

Thus, its business practices formed around what is called a “least first cost” model: Build and sell inexpensive systems and ignore the leakage and wasted energy. With energy costs low (and with the reasons for this hidden, if in plain sight), uncomfortable people could just mask the system waste and inefficiencies by cranking the heat higher or lower. Which is a nice snapshot of what, writ large, has gotten us in this grand climate change mess.

Energy Auditing

A simple energy audit can tell homeowners what needs to be done and what will be the most cost effective measures. Stimulus in this area could lead to consumer demand that will stand on its own.

Print option

would you be willing to have a print option? It would be so helpful for me as I often want to print and share and article that I read on your site> Thanks

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