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You want it all. Of course you want abundant, cheap heat in the winter, and central air-conditioning for the hotter months. You work hard, so why should you suffer when you get home and want to relax? But there’s that nagging, annoying issue of global warming, not to mention ozone depletion, and you think you have to cut back, right? Or that having heating and air-conditioning whenever you want regardless of the temperature is like burning the candle at both ends? That an affordable, green, renewable-energy powered HVAC (Heating, Ventilating, and Air Conditioning) system is still far off in the future? That you must stay sucked up to the increasingly expensive and still-polluting oil, gas, nuclear, and electric “grid” if you want to have comfort 24/7, 365 days a year?
Wrong. We do not have to burn anything to heat and cool our houses. Nor do we have to pay an arm and a leg for the privilege of gas or oil or AC electric-grid power that is coming from coal or an aging nuclear reactor to run a central-heating and cooling HVAC system.
Right now there is practical, affordable clean technology that allows us all the bells and whistles when it comes to HVAC, without us having to worry about building new reactors, rising fuel costs, or global warming from burning fossil fuels. Some of these systems can even work day or night with no electrical-grid connection at all. (Though I think it’s actually good to be on the grid, so if you generate more electric energy than you need you can sell it back.) These new HVAC systems do not use CFC and HCFC refrigerants that deplete the ozone, as do old systems that are now in fact being phased out of use; rather, they rely on geothermal or photovoltaic (PV) solar energy.
My candle burns at both ends
It will not last the night;
But ah, my foes, and oh, my friends—
It gives a lovely light.
–Edna St Vincent Millay
Architect Laszlo Kiss installed a combination geothermal-solar PV-powered HVAC system for his newly constructed “green” house in Sag Harbor, which he calls the ASAP House (“House About Saving a Planet,” asaphouse.com). The house is the first of its kind, and a model for zero-net-energy modern modular homes that he is manufacturing in Pennsylvania. “My experience with geothermal has been very good” he says. “The system works well in the heating and cooling mode. The geothermal pumps in the basement are very small and quiet. I got a $4,600 rebate from LIPA, and now we also get a preferred electric rate from LIPA and pay less per Kilowatt because we installed the geothermal system.”
Not that Laszlo has to worry too much about his electric bill, as he also installed a 10.5 KW Sharp solar PV array, so the electricity from the sun powers not only the heat pumps—the whole house is a net-zero energy user. I asked him about the extra cost for his HVAC system, as many people continue to use the argument that the cost of going this green by using geothermal and solar PV is prohibitive. He claims “The system added about $40,000 extra to the cost of the house, but the monthly cost of adding that to a mortgage that is amortized over 30 years is actually less than what we would pay for heating and cooling.”
That said, many industry insiders, including Rudy Holesek, president of Apollo HVAC Corporation, are still questioning the economic viability of incorporating geothermal and photovoltaic into building projects. “We have tried to introduce this technology on some projects . . . but the payback is simply too long in most cases.”
However, many pioneers in the green building movement are finding that with the right combination of products now on the market, you can use the earth, air, sun, and water to heat and cool your house year round with carbon-neutral, zero-net-energy HVAC systems that can run with or without the grid that we mistakenly take for granted.
Check out the HVAC options mentioned at right, and welcome to the future.
GOING OFF THE GRID
Solar-Powered DC/AC Hybrid Heating and Air-Conditioning Systems
Undoubtedly there will be many more AC/DC solar-powered products coming in the future, but Solcools Millenia HVAC (solcool.net) is by far one of the most amazing products I have seen yet. It heats and cools your space with power from its own solar panel, and has a 12-hour backup battery so it works even at night or when the electric grid is down. Options include the ability to power a DC fan and lighting, UV air sanitizing, and it can even produce drinking water as it condenses humidity out of the air. What’s also cool is the Millenia can run on AC grid power, as it has its own inverter. So even if you are afraid to live off the grid, this little wonder will let you be on and off the grid at the same time. Super energy efficient, Millennia is reported to have a 20 SEER rating and be 50 percent more efficient than other high-efficiency HVAC units. It uses non-ozone-depleting HFC 134A and HFC 410A refrigerant, which earns LEED credits from the U.S. Green Building Council.
Air-Source Heat Pumps
Air-source heat pumps have been a main source of home heating and cooling in the South for many years. They have not been
used in colder climates because until recently they did not work well in cold weather. But the Hallowell company (gotohallowell.com), in Maine, has come out with Acadia, a new air-source heat pump HVAC product that moves heat out of your home in summer, and in winter can deliver heat into your home at temperatures as low as -30ºF. Its air-source technology is similar to that of a refrigerator; using a refrigeration cycle, refrigerants remove heat from one location and direct it to another. This heat pump looks the same as a central air conditioner and is located outside of your house. Inside your home there is an air handler attached to the ductwork. Between the outside unit and inside unit runs a pair of copper pipes, through which the refrigerant circulates to transfer heat back and forth. Acadia is reported to be extremely effi cient, much more so than any other kind of conventional heating or air-conditioning. What’s more, it burns no fossil fuels and uses just electricity, thus opening the equation up to a solar electric power offset. If you get a solar PV array to power the electricity for the unit, you will have a carbon-neutral zero-net energy HVAC. If you really want to go wild, get a small battery backup storage system and inverter so you can still keep the Acadia going for the short times when the grid is down, thus giving you heating and cooling 24/7 without worrying about grid failure. It also uses non-ozone-depleting HFC 410A refrigerant, and costs only slightly more than a conventional HVAC system.
Geothermal Ground-Source Heat Pump With Solar PV
The great thing about geothermal systems is that in addition to having an HVAC with an air purifier for your house, you can also set it up to give you hot water for your home, pool, or spa, as well as use it for snow melting and to heat radiant floors. How much of an econo-brainer is all that? Geothermal heat-pump systems use the constant 55ºF temperature of the ground to efficiently transfer heat to and from your home via liquid in the tubes buried or drilled under the frost line. Thus, unlike with the air-source heat pumps, a groundsource geothermal system does require excavating or drilling to loop tubes under the frost line of the earth. Depending on the property, drilling or excavating could be somewhat costly. But I have been in a zero-net-energy house in Gardiner, NY, where I installed a geothermal ground-source heat-pump system when the excavating and drilling was being done, and the extra cost was minimized by this smart planning. The house in Gardiner has a solar PV array that was big enough to not only power the electricity needed to run the heat pumps, but also powers the electricity for the whole house. Thus, just like with the air-to-air heat pumps, a geothermal heat pump HVAC burns no fossil fuels, and the electricity used to power the pump can also be 100 percent offset by solar PV. Battery backups would come in handy when the electric grid fails. Or, if you really wanted to go the extra green mile, you could figure out a way to divert some of the PV power you generate through an inverter directly to the heat pump in case the grid failed and battery power ran out. Try to get a heat pump that uses the non-ozone-depleting refrigerants available (check out WaterFurnace's PremierE R410A at waterfurnace.com.)
THOUGHTS? COMMENTS?
We’d love to hear from builders, contractors, and homeowners about their experiences and thoughts on the economic viability of geothermal and solar PV HVAC systems. Email us at editor@canvasli.com
Paul McGinniss is a writer, real estate broker, green building and renovation consultant, and a green media and PR consultant. Visit his blog at paulemcginniss.blogspot.com <http://www.paulemcginniss.blogspot.com>
