Q Which uses less electricity; power tools that you plug in or ones that are cordless and you have to recharge?
For a given amount of work, most portable power tools (corded or not) will use about the same amount of energy. So, the difference would be in the amount of electricity used directly (for the plugged-in tool) versus what's used to recharge the battery of a cordless tool.
The two energy uses are nearly the same; recharging uses a very small amount more. Bottom line: If you're trying to choose between the two tool options, energy use won't be a deciding factor.
While the added energy use of a cordless power tool is negligible, the overall impact of battery charging can be notable in a typical U.S. household. That's because many people aren't aware that chargers draw energy as long as they're plugged in. That wasted energy can really add up in a home with multiple portable devices, like rechargeable tools, phones, cameras, laptops, hand-held vacuums, and more. To eliminate this money waster, charge your batteries just until they're full, and unplug the charger when it's not in use.
QWhat's a net-zero home? Does it really use no energy? Does it cost more to build?
A net-zero home is a house that produces as much energy as it uses. This home generates the energy it needs from renewable resources like wind, sun, and water. The house design focuses on minimizing energy needs through air sealing and insulation, energy-efficient lighting, appliances, space-heating, water-heating, and ventilation systems. Also, a thoughtfully-chosen building site and orientation are needed to enable you to make optimal use of renewable resources.
The key factor in preventing net-zero construction from being more expensive than standard construction is house size. In other words, if you take the average-size new U.S. house (2,438 square feet) and use the above approach to designing and building it, then yes, it will cost more to build; not only for the house itself but for the larger heating systems and renewable-energy system that will support it. But if you apply net-zero design techniques to a small house, (say 1,200 square feet or so), it is possible to build at a cost comparable to that of standard small-house construction.
I want to point out that, to determine the cost-effectiveness of net-zero construction, (or any energy-efficient construction), any higher initial expenses need to be weighed against the lower energy bills that you can expect year after year. Also, keep in mind that the most cost-effective time to incorporate energy-saving and/or renewable-generating elements into a home is in the design and construction phase. To determine the costs and benefits for the house you have in mind, I recommend starting by contacting Efficiency Vermont about the Vermont ENERGY STAR Homes service and contacting Renewable Energy Vermont at www.revermont.org. Best of luck!
Q I'm thinking about getting an energy audit of my house. Can you tell me what a good auditor should do and how I can find one?
A: Sure thing. A qualified auditor will evaluate the whole house and will identify the causes and solutions for any energy efficiency or health/safety problems. The auditor will look at the heating system, lighting, appliances, windows, and insulation and will understand how these elements interact with each other to affect your energy use, comfort, health and safety.
Specifically, the auditor will:
- use a special fan, called a blower door, which fits in an exterior doorway and changes the air pressure in the house so that air leaks can be found and sealed;
- assess the presence and amount of carbon monoxide and gas leaks;
- provide you with a proposal for making recommended improvements; and
- help you prioritize cost-effective energy-saving home improvements.
Home Performance with ENERGY STAR contractors are trained to perform energy audits. Some of these contractors also fix many typical causes of problems discovered in an audit. In addition, Home Performance with ENERGY STAR contractors can provide you with access to discount financing for energy-efficient home improvement loans.
A.They can be. As with any other home, the energy efficiency of a prefabricated home depends on the performance of the building's envelope (insulation and air sealing) and the efficiency of the heating and hot water systems. The detail and care used while assembling the components will have a significant impact on the energy efficiency of the final product.
One feature that has a great impact on the air tightness of a modular home is the location where the modules join. It should be well sealed with expanding foam or other suitable material. Given good sealing between the modules, a modular home can be exceptionally tight, but air sealing is just one piece of the energy efficiency picture. An efficient heating system, a well-insulated foundation, efficient lighting and appliances and many other pieces all contribute toward reducing your energy bill.
Whether you're constructing a modular or site-built home, Efficiency Vermont can help. Call us at 888-921-5990 to learn more about the Vermont ENERGY STAR Homes service for homeowners and builders of new homes. We provide advice and guidance on the most efficient building practices and materials and can help you make sure your new house meets Vermont's energy code.
A. Radiant flooring does feel wonderful. And while I hate to discourage you, you should know that a radiant floor doesn't necessarily save energy and that the extensive piping required is expensive to install.
As a retrofit in a framed floor, radiant floors are better described as "warm floors." You'll get the best result if your basement doesn't have a finished ceiling and you currently heat with a hot water boiler. You will need to remove any carpet in areas where you want warm floors. Even then, the system will perform differently than a true radiant floor that has high mass (concrete) and a non-insulating floor covering (tile).
If your floors are cold, you may be able to improve your comfort by reducing air leakage and insulating the basement. A certified Home Performance contractor can help you get to the bottom of your comfort issues and provide recommendations to help you improve comfort and save energy. You can find a list of certified Home Performance contractors by visiting the Marketplace.
A. Icicles and ice dams are caused by snow melting on the roof, then freezing as it drips over the eaves. This snow melt is usually due to heat loss from inside the house. A metal roof may reduce snow and ice accumulation by allowing them to slide off, but replacing your shingled roof with a standing seam roof won't necessarily prevent ice dams. Icicles and ice can still build up on some roofs regardless of the roofing material.
Since a metal roof may simply mask the problem, you'll save yourself a lot of work and the expense of replacing your roof if you find the source of the heat loss instead. Have air leaks, such as those around a chimney or recessed lights, sealed by a Home Performance contractor. This should reduce your heating costs and help solve your ice dam problem. For a list of professionals in your area, visit the Marketplace.
A. You're smart to ask. Depending on the soil conditions and the material used to build your foundation, there could be risks associated with insulating the existing foundation of a 200-year-old home.
A conservative approach - and possibly your best option - would be to insulate the outside of the foundation from the top of the wall down one or two feet below grade. Depending on your specific situation, you could excavate around the foundation, install rigid foam board against the foundation, then backfill. This will reduce heat loss where it is greatest and still allow some heat to warm the ground near the foundation to reduce the risk of frost heave damage.
You can also insulate the foundation on the inside. Use rigid foam if the walls are smooth enough to prevent significant gaps or air spaces behind the foam board. If the foundation is rough or uneven, begin one to two feet below the exterior grade level and use spray foam up to the floor above and over another six inches to eliminate air leakage and heat loss around the rim band.
For other ways to save energy in your home, contact a certified Home Performance contractor. These professionals can help you make energy-saving improvements. You can find a list of certified Home Performance contractors in your area at the Marketplace.
Q Can Efficiency Vermont help me to build a new energy-efficient home?
A. I'm so glad you asked this question! One of the reasons Efficiency Vermont is here is to help you find resources and people who can aid you in meeting your goal of building an energy-efficient new home. Give us a call to find out how you can enroll in the Vermont ENERGY STAR Homes Service. You'll get your own personal project manager who can help you get the best value from your home's efficiency, durability, and comfort and work with you and your builder to ensure a healthy house that meets Vermont's Residential Building Energy Standards code. Your project manager can also keep you informed about incentives available for owners and builders whose homes meet Vermont ENERGY STAR Homes criteria.
The Vermont ENERGY STAR Homes Service is completely free of charge to you, so don't hesitate to take advantage of this valuable, hands-on guidance from a building energy professional.
Q Can you suggest ways to make energy-saving choices when I remodel?
A. If you're remodeling, it's the perfect time to "add in" some energy-saving measures.
One fairly easy way to increase your fuel savings is by air sealing - and your attic is the perfect place to focus your attention. Just be aware that in the process of sealing air leaks, indoor pollutants, and moisture, may become more concentrated. You'll want to think about an energy-efficient ventilation system to keep this potential problem in check.
One thing I've noticed is that additions are often poorly air sealed to the existing house. Take the time to check on this and make sure the connection between the old and the new is a tight one.
Probably the most popular remodeling project these days is the kitchen. And there's nothing like an up-to-date kitchen to add value to a home. Just keep in mind that your kitchen is the most energy-hungry room in your home, and always look for the ENERGY STAR when buying new appliances and lighting fixtures.
QI've been hearing about something called Home Performance with ENERGY STAR?. What is it?
A. Home Performance with ENERGY STAR? is a whole-house diagnostic service offered by Efficiency Vermont. Benefits include making your home more comfortable, healthier, safer, and more durable, while lowering your energy costs. The service, which can include a comprehensive home assessment, professional advice, assistance in prioritizing improvements and information on energy-saving products, is available through Efficiency Vermont's network of technicians. To see if this service is right for your home, call 1-888-921-5990 x 2000. There is a fee for this service and you may need to meet eligibility requirements.
Q How much does an energy audit cost? Who is qualified to do it?
A: An audit can cost $50 to $100 an hour. Talk to an auditor by phone first, and tell them what type of information you're looking for, to be sure that they can address your concerns with an audit. Many auditors charge for travel time, so ask about that. You can find a list of energy auditors on our website. Or, you can call me and I'll look for one closest to your house. Now that I've given you the basics, I'm wondering what the problem is that makes you want to hire an auditor. If high bills are a concern, go to our website or give me a call. There may be simple things you can do yourself to reduce those bills.
A: Each of these heating systems uses electricity for fans or pumps that either move heat into your living space or exhaust combustion gases from the house, or both. New furnaces can use between 100 and 1,800 (kWh) of electricity per year. Boilers use up to about 400 kWh/year and pellet stoves use about 100 kWh/year. At a rate of 12.5 cents per kWh, that adds up to, respectively, about $12.50 to $225, $50, and $12.50 in annual electric costs.
If you opt for a furnace, look for an ENERGY STAR® qualified model with an efficient fan motor, which is sometimes called an ECM or brushless DC motor. These fans use half to two-thirds the electricity of standard furnace fans. Another energy-saving furnace feature is a variable-speed fan with a multi-stage burner, which reduces airflow and burner output to match the heat needs of a house. Also, well-installed ductwork can save both electricity and heating fuel while increasing your comfort.
There's more energy-saving info available for new-home builders than I can fit in this column. However, Efficiency Vermont's "Vermont ENERGY STAR Homes" program can provide it. We'll help you think through questions like this and many others and we'll provide testing of the new house to ensure that your efficiency goals are met. You can call 888-921-5990, toll-free, to learn more. Best of luck with your house!
A: Vermont's energy code is designed to ensure that all new homes contain specific energy-efficient features. But there are factors not addressed in the code that have an impact on how much energy you use. For example, a home built to code isn't necessarily one that has been comprehensively air sealed. Air leaks can be a cause of high heating costs. A Home Performance with ENERGY STAR® contractor can find and fix air leaks for you. These contractors also can conduct a whole-house assessment, and let you know about other steps you can take to reduce energy costs and increase your comfort.
Another significant factor in heating-fuel costs is simple human behavior. There are many energy-saving actions under your control, such as using a programmable thermostat to automatically lower the thermostat temperature when you're not home. See that radiators, baseboards, vents, and air returns aren't blocked by furniture, rugs, drapes or even piles of clothes. When you're not using the fireplace, and the ashes are cold, close the damper to stop the constant pull of air up the chimney. You can find more energy-saving tips, as well as a list of Home Performance with ENERGY STAR contractors, in the Home Performance with ENERGY STAR section of the website.
For readers about to build, I'll mention that builders who construct houses to meet Vermont ENERGY STAR Homes qualifications provide owners with homes that are tested and verified to surpass state code standards for energy savings. These homes also must pass ENERGY STAR standards for durability and indoor air quality. You can find out more through Efficiency Vermont.
