2/21/2013 9:58:00 PM GREEN BUILDING: Energy-efficient homes not necessarily green - and vice-versa
By PAUL SCRIVENS Special to the Courier
Question: I have heard a lot about green and energy efficient homes, but much of it is confusing. What are the real benefits to the homeowner and what does it really cost?
Answer: Green homes and energy-efficient homes are closely connected; however, you can have an energy-efficient home that is not necessarily green, and a green home that is not particularly energy efficient. Energy-efficient homes keep the outside uncontrollable weather out and the inside heated and cooled conditioned air in. However, even though a home may have a very tight and resilient barrier between the inside and outside environment, a certain amount of conditioned space-generated energy is required for human comfort. This energy can come from either renewable or traditional energy sources, but either way an efficient heating and cooling system is required.
The primary complaint from homeowners is that certain rooms are colder than others, that drafts are debilitating and energy bills are crippling. Little Johnny's room is freezing and the bathroom is damp and cold; there is a force-eight gale blowing across my feet in the family room and the heating system isn't working properly as the whole house is always cold! We have to keep temperatures low because we can't afford the heating bills, so we wear multiple sweaters and blankets to keep warm. Sound familiar?
If built correctly, an energy-efficient home solves these problems and I know I have one. It's the most comfortable home I have ever owned. The rooms have stable temperatures that barely move, there aren't any drafts and there are no cold or hot rooms. The rooms stay warm in winter and cool in summer, and we keep the room temperature at a comfortable 72°F. Because our home is so tight we can keep our inside temperatures higher and our energy bills are a third of a typical home our size.
Our heating and cooling system is a very efficient dual fuel unit that uses an air-based heat pump most of the time and a natural gas back-up unit that kicks in at lower outside temperatures. The systems crossover point is configured based on fuel cost and system efficiency. We also have built in humidification and mechanical ventilation due to the home's tightness.
The green aspects of our home address water conservation, environmentally acceptable materials and health and safety considerations and will be discussed in subsequent articles. For now we will concentrated on energy efficiency and comfort only.
What does it cost to build an energy-efficient home over a typically built home? My builders quoted a conventional stick frame home and another where we added energy- efficient technology in the form of sealed foundations, integrated concrete forms for basement and crawlspace walls and integrated structural panels for the main walls. Windows, doors and roof were the same in both cases; the roof had twelve inch thick R43 foam insulation. The roof, basement and crawl space were indirectly conditioned.
We totaled the envelope costs and found a difference of between 10 percent and 12 percent between the two. For the overall home a 2 percent to 3 percent increase was calculated. As all the costing is based on square footage, the ratio should be approximately the same for any size home.
It should be recognized that many of the materials used in an energy-efficient or green home cost the same as in a typical home. It is the selection of those materials and products that make the difference not the cost.
For more information, visit www.greenhomeenergyadvisors.com.
Posted: Monday, February 25, 2013
Article comment by:
Shari, you have a very good question and one that is difficult to give a black and white answer too. I do expect energy prices to rise over time even though the base generating materials are declining the utility companies will not allow their profits to drop and will therefore raise fixed costs associated with delivery of service. Government will not want to see taxes drop either.
Regards solar it is a long term investment with long payback periods and it all depends on how much energy you use and how tight you home is. The best move is to make sure you are not wasting energy through a leaky and poorly insulated home. A tight home needs less energy and therefore a smaller solar system.
Posted: Saturday, February 23, 2013
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Is this a good time to commit to a 20 year lease for residential solar panels? Right now solar doesn't decrease the homeowner's monthly cost, but the projection is that APS will continue to increase their costs and therefore, over the years, the homeowner will see a savings. Will solar technology improve in the next few years and solar leasing decrease and therefore, one should wait?