- Energy Audits
- Heating, Ventilation & Cooling
- Air Sealing
- Water Heaters
- Solar Thermal
- Contractors and Architects
- Rebates & Financing
- Building Science
F.A.Q Energy Efficiency at Home and Energy Retrofits
Frequently Asked Questions
When asked most people will say that the #1 polluter is cars on the road. In truth, according to the Department of Energy, in the United States residential buildings cause the greatest amount of emissions, more than cars and light trucks combined. If you think about it this makes sense, we use lighting in our home, we heat and cool our home, we heat and cool our food…and this all happens 365 days a year. Multiply that usage by the 130 million homes in the US and you can appreciate the magnitude of our energy and water consumption at home.
Environment: How Green is AHE?
We do our best to walk the talk. When possible, we use the greenest buildings products available for our construction projects. Our trucks run on a blend of bio-diesel and our cars are hybrids. We are in the process of getting our new office to be certified by the Bay Area Green Business Program.
Carbon monoxide (CO) is a colorless, odorless and poisonous gas. It is produced during the incomplete burning of fuel, including the natural gas of your water heater, furnace, range and oven. It is extremely important that CO levels are below accepted minimums and that the CO is properly exhausted from the house.
Low to moderate CO poisoning can cause symptoms that are similar to a flu, including: fatigue, headaches, nausea, dizziness and shortness of breath.
The long-term exposure limit for CO is 35 PPM. Typically, we recommend an appliance to be serviced if it is near or over this level. If any appliance reaches over 100 PPM we recommend discontinuing the use of the appliance until is serviced. If the ambient CO level at any place in the house is above 9 PPM we recommend immediately identifying the cause and fixing the issue.
Health/Safety: Do You Test for Mold and Indoor Air Quality?
We do not directly test the quality of indoor air or mold, however we do investigate and remediate many issues that are related to the root cause of indoor air issues. Adequate ventilation, properly functioning combustion appliances, minimizing high humidity are all important issues that we address which directly impact indoor air qualt
HVAC: Why Duct Leakage Such a Big Deal?
Duct leakage is not only an efficiency issue, but can also significantly impact your indoor air quality and home comfort.
• Efficiency: According to The U.S. Dept. of Energy: “You can lose up to 60% of your heated air before it reaches the register if your ducts aren’t insulated and they travel through unheated spaces such as the attic or crawlspace.” In the homes we have tested over the years we have found that duct systems in older home in the Bay Area leak an average of 30-40%. That’s like throwing away $0.40 for every dollar you spend on heating!
• Air Quality: Leaky ducts are often located in the attic or crawlspace which can cause major indoor air quality issues. For example, during the winter the crawlspace will be damp or have high humidity, which can cause mold growth. When the furnace goes on, the leaky duct system can draw this unhealthy air and distributes it throughout the house. It’s no wonder that the EPA states that indoor air quality is 10X worse than outdoors!
• Comfort: Another common complaint is that some rooms are too hot/cold or don’t receive enough air flow. Fixing the leaks can provide more air flow to the rooms where you want it. To help balance the system and deliver correct air flow to individual rooms, we can adjust the in-line dampers on the furnace to redirect the heat where we want it. If you have an older duct system, you may need to have dampers installed in order to do this.
Possibly. Depending on your specific home, floor and/or wall insulation may or make not be the highest priority in moving toward your goals. Properly assessing and/or testing your home will enable us to determine the most cost-effective measures to making your home more comfortable, healthy, and efficient.
Insulation: What is the most effective and eco-friendly insulation?
We use a few different types of insulation in our work, depending on the needs of your specific situation. Most of our insulation work calls for cellulose insulation, which is approximately 85% post-consumer recycled paper and 15% inert, non-toxic, hypo-allergenic borates. (The borates make the insulation fire and pest-retardent.) We never use insulation products with formaldehyde or any other carcinogenic substances. Spray Foam or rigid foam is typically 100% petroleum based, but it is a good solution for vaulted or cathedral ceilings. Foam insulation has the advantage of being an accepted air or vapor barrier which may be required by building code such as when being installed in a vaulted ceiling. Closed cell foam has the highest R-value which is advantageous when there isn’t a lot of room in the walls or ceiling for insulation.
Insulation: Will insulation make our home cooler in the summer and warmer in the winter?
Yes! The exact same home improvement measures that help make your home more comfortable, healthy, and efficient in the winter help achieve these same goals in the summer. A properly air sealed, weatherized, and insulated home performs well all year round, through hot and cold spells alike!
Insulation: What are the relative costs for different types of insulation?
Fiberglass is typically the cheapest option but has major performance issues that make it’s life-time costs much more expensive than the alternatives. Cellulose is the moderate cost option and typically the most cost-effective solution. Foam is the most expensive option but is necessary for certain applications.
Insulation: I have knob and tube wiring. Can I insulate over this?
The electric code DOES allow for insulating over knob and tube wiring – If your house still has live knob and tube, a licensed electrician will come and check that it is in good condition with no split wires and open boxes. He then signs off on a C-10 form that approves that attic for insulation over the wiring. We have an electrician that we work with that provides this service. If he finds issues, he charges time and materials for repair.
Home Performance is a relatively new construction trade. I say new, because many homeowners are not aware of this field, but it has been around for over 30 years. It’s beginnings were really birthed from two directions. On one side, the energy crisis in the 70s spurred an awareness about our energy consumption and the amount of energy wasted in homes. On the other side, experienced builders and contractors began realizing that the building practices they had learned and had been using for years did not always result in homes that were comfortable to live in. The result was that people started looking at construction from a more scientific perspective and began testing how well the building performed. They asked home owners questions, they began doing studies on different building practices, they built modeling software… And slowly a new field developed based on building science that didn’t just look at the pieces of the building but also addressed the performance of a building.
Performance: Is Home Performance a Good Investment?
YES! The impact of home performance work is many-fold. First, it’s a good investment because the work we do lowers your utility bills. Commonly we lower customer’s heating and cooling bills by 40%. If you look at energy prices historically they have increased 7% consistently each year. So lowering your consumption today has a better and better return over time as the price of energy keeps going up. Second, the work we do makes your home more comfortable. Most people don’t realize how much room for improvement they have in their home and assume that when it’s cold outside their house will be cold or they have to crank up a noisy furnace. Our work makes a home comfortable throughout the year.
Performance: Will Our Home Feel Different Right Away?
This depends on what condition your home is in when we start, and what work we do. If we button up your drafty home and take your attic, floors, or walls from little or no insulation to fully insulated, you will most likely notice a huge difference immediately. If we repair your leaky duct system and tune up or replace your oversized and inefficient furnace, you will most likely notice less dust, suffer fewer respiratory issues, and see a significant savings in your heating bill as soon as you start using your upgraded system. If we replace your conventional water heater with a solar thermal system, you won’t notice any difference in your home’s environment, but you will most likely see a significant savings in your water heating bill right away.
Performance: What is Air Sealing?
People often complain about having a “drafty” home. Air sealing is the process of sealing all those little (or not so little) holes and gaps in the building shell. Typically, we use a blower door to exhaust air from your home and provide us with information about the severity of drafts or leakage. A healthy home should have 0.35 ACH (The air-tightness of a home is measured in ACH; the number of times the home’s air is replaced by outside air in an hour) or the equivalent of replacing 1/3 the volume of air every hour. A higher ACH means your house is draftier than recommended and wastes energy. This can also cause air to be drawn in from unhealthy areas such as the crawlspace and garage.
It depends. Although this is a terrific question, unfortunately there are simply too many variables in any given home to be able to provide you with a clear and accurate answer. Just a few of the variables that we can’t ever fully predict include: your utility use, the constantly-changing price of utilities, and the weather! We can tell you that all of our work is aimed at creating increased efficiency and an improved quality of life within your home. Some of our work provides dramatic and immediately noticeable improvements, both in your home’s environment and in your utility bills. Other work is more subtle. We encourage all of our customers to pay very close attention to your experience in your home, as well as your utility bills before and after our work, then please share the comparison with us.
Savings: What Are the Tax Credits for Energy Efficiency Work?
Tax credits are available at 30% of the cost, up to $1,500, in 2009 & 2010 (for existing homes only) for: Insulation, HVAC, Water Heaters.
Tax credits are available at 30% of the cost, with no upper limit through 2016 (for existing homes & new construction) for: Solar PV and solar hot water
For more information visit: http://www.energystar.gov/index.cfm?c=tax_credits.tx_index
What Rebates Are Available for Home Performance Work?
There are numerous rebates from PG&E and local water utilities.
For PG&E rebates visit: http://www.pge.com/myhome/saveenergymoney/rebates/
For EBMUD rebates visit: http://www.ebmud.com/drought/rebates.html
Some people complain about turning on the faucet or shower then waiting a long time for hot water.
A possible solution is a domestic water re-circulation pump. This device provides instantaneous hot water at the times you need it most. It can be installed at the water heater tank or can be installed very economically below the bathroom sink. The pump can be set to turn on automatically in the morning or be turned on manually with a remote control.
Another water and energy saving alternative to the recirculation pump disucsses earlier is to install a thermostat controlled showerhead. This is an effective and much cheaper solution. When the shower is initially turned on the showerhead gauges the water temperature. When the water temperature reaches approximately 95 degrees the showerhead automatically turns the water flow to a trickle. This prevents the hot water from going down the drain before you’re ready to get in the shower. When you turn the valve on the showerhead, the water flow then resumes.