Americans are regularly encouraged to maintain a “low carbon footprint”—that is, to use as little fossil-fuel energy as possible. While many of us have switched to energy-efficient cars, fewer have switched to energy-efficient homes. The fact is, homes with oil or gas furnaces consume about 6 percent of all fossil fuels nationally. Fortunately, there are many ways to heat and cool a house to lower, or come close to eliminating, its carbon footprint. Recently there has been an upsurge of homes retrofitting photovoltaic (PV) solar electric systems, which with current credits and rebates have become more affordable. With a battery backup system and a large enough array of PV panels, a home can supply most of the total electricity it needs.

With a PV array, a full-house active heating and cooling system can be retrofitted through the use of variable refrigerant flow (VRF) low-velocity HVAC mini-split units that are very energy efficient. These systems can be installed with ducted or ductless units, which require a wall-mounted blower assembly in each room to heat or cool a general area. This system, coupled with additional insulation built up under new exterior siding, can lead to high energy efficiency.

Another alternative is a passive solar design, which uses thermal mass to store and radiate heat from the sun. Passive solar can also provide ambient cooling by capturing lower temperatures from nighttime air or from any part of the structure that’s built below the frost line.

Any house can be retrofitted with passive solar. This can involve something as simple as installing larger windows or a patio door, which will allow the sun to warm a thermal mass such as a cement or tile floor, a garden pond or a water wall feature. Deeper roof overhangs will prevent the sun’s heat from penetrating the house during the summer months.

A sunroom addition can also be installed with a slab and a gravel mass below the frost line. This will have an ambient effect similar to a basement, which is always warmer in the winter and cooler in the summer. To eliminate the need for a furnace or air conditioner, a ducted mechanical air or hydronic radiant tubing system can be run through this thermal mass as well as other supplementary heating and cooling systems.

A home with natural radiant heating and cooling is a healthier and certainly more sustainable environment, offering higher energy efficiency and a lower carbon footprint.

For more information, contact Lou Levy Construction at 914.804.4145 or visit LouLevyConstruction.com.