Green Options

Home automation systems (such as Colorado vNet and Control4) are becoming a necessary amenity in any high-end home, but are they also a new tool in our fight to reduce energy use and global warming? After all, these systems are designed so that you can control your high-end AV components, home security system, lighting and HVAC from one device (or via the web from somewhere else), so why not add energy conservation to the mix, right?

The idea is that these high tech systems will minimize or eliminate the wasted energy from lights left on by accident, vampire loads from home equipment in the “off” state, thermostats set too high or low for usage patterns or climate conditions, etc - the automation systems themselves will set things right even if you forget. We’ve certainly written about how important it is to kill of these wasteful elements, but are they big enough to warrant buying one of these systems just to reduce them?

Author’s note: the following article on home heating is the third in an eight-part series. This article addresses climate conditions found in the San Francisco Bay Area, but may have applicability elsewhere.

Forced air systems are the most common heating systems in California and are used in most new construction elsewhere. They have two big advantages: they are cheap to install, and they provide heat at a moment’s notice. Having “instant-on” heat is vital for intermittent use spaces like ski cabins. Otherwise, forced air is the least energy efficient and least comfortable way of heating a typical home. Why?

Ventilation and Heat Loss

For the health and well-being of its occupants, a home must exhaust stale air and refresh it with new air drawn from outdoors. Forced air systems heat and blow this air, via ducts, throughout your house. Since new air is continually entering and leaving, you are heating the outdoors.

Author’s note: the following article on home heating is the first in an eight-part series. The series specifically targets climate found in the San Francisco Bay Area, but has applicability elsewhere.

According to the U.S. Department of Energy, heating and cooling amounts to 46% of all energy consumed by our homes. Water heating uses another 14%. In coastal California, where extreme heat is rare and winters are mild, a properly sited, well designed passive solar home can generate its own heat and hot water, and do without air conditioning.

Historically, few homes are so well sited or built. Since our area has more heating days than cooling days, most homeowners need a heating system. What few know is that many indoor air quality problems can be by-products of forced air heating, ventilation and air-conditioning (HVAC) systems installed in their homes.

Big buildings save energy by controlling which areas need to have heating or cooling, and not wasting energy on those spaces when they are not occupied. Similar features are sometimes found on high end homes (and are probably almost a necessity on the oversized starter castles spread across the outskirts of every city). But systems like that are hard to retrofit into smaller, older homes.