Preguntas Más Frecuentes:
HVAC:
1. Is there more energy saved by using a programmable thermostat as opposed to manually turning the furnace up and down (assuming no forgetting?) Why? view answer2. How well do programmable thermostats work in homes with hot-water boiler/radiator heating? view answer
3. How do you change the thermostat? view answer
4. We have been 'told' that, with our boiler heat, it is less efficient to change the temp setting (e.g., use a programmable thermostat to drop the temp at night) than to keep it steady. We have a brand new boiler... Please tell me this is not true!!!! view answer
Light Bulbs:
1. I purchased CFL's but they are dimmer than the incandescent light bulb, how do you know which bulb to get? view answer2. I purchased CFL's but the light was cold and we didn't like it. view answer
3. What do I need to know to shop for fluorescent light bulbs, which have the least delay in turning on? What have the improvements been in CFLs over time in terms of how fast they light up? view answer
4. I heard CFL's have mercury in them, is that true? view answer
Insulation:
1. Can insulation really make a difference in my heating bills? view answer2. What does R-value mean? view answer
3. How much insulation should we have in our attic? view answer
Weatherizing your home:
1. Can weatherizing really make a difference in my heating bill? view answer2. How do I know where we need to weatherize? view answer
3. What's the difference between latex and silicone caulk? view answer
Frequently Asked Questions Full Text:
HVAC:
1. Is there more energy saved by using a programmable thermostat as opposed to manually turning the furnace up and down (assuming no forgetting?) Why?
There is not any additional savings associated with a set back thermostat when compared to doing it manually. The only advantages to setback thermostats are convenience and being able to wake up to warmer temperatures.2. How well do programmable thermostats work in homes with hot-water boiler/radiator heating?
When using a programmable thermostat with a boiler the energy savings are the same as for a forced air furnace. A boiler will have a lag time however. Old systems with large radiators will have a longer lag time than newer baseboard systems. You can compensate for this by turning your heat back programming the thermostat to switch the heat back on earlier. For example, if you want it to warm back up to 68 degrees at 7:00 AM, set the thermostat to turn up the temperature at 6:30 AM At first it will be trial and error to see how long it takes to warm up to the desired temperature.3. How do you change the thermostat?
You may be changing from a round thermostat to a rectangular thermostat, which may require painting the wall behind the old thermostat. Hooking it up is pretty basic. You will connect the red wire (labeled R on the thermostats) from the old thermostat to the new one and connect the white wire (labeled W on the thermostats) from the old thermostat to the new one. The new thermostat will require batteries, which are not included. Remember to change the batteries in the fall when turning on the heat for the first time.4. We have been 'told' that, with our boiler heat, it is less efficient to change the temp setting (e.g., use a programmable thermostat to drop the temp at night) than to keep it steady. We have a brand new boiler... Please tell me this is not true!!!!
Good news!! It is not true. Energy savings for a boiler are the same as energy savings for a forced air furnace. A boiler will have a lag time however. Old systems with large radiators will have a longer lag time than newer baseboard systems. You can compensate for this by programming the thermostat to turn your heat back sooner. For example, if you want it to warm back up to 68 degrees at 7:00 AM, set the thermostat to turn up the temperature at 6:30 AM At first it will be trial and error to see how long it takes to warm up to the desired temperature.Light Bulbs:
1. I purchased CFL's but they are dimmer than the incandescent light bulb, how do you know which bulb to get?
This chart shows the equivalent light bulb to purchase. Buy CFL's the Energy Star models as they have been tested to be the equivalent.| Incandescent | CFL Equivalent |
| 20 W | 5-6 W |
| 40 W | 8 W |
| 75 W | 11-13 W |
| 100 W | 18-20 W |
| 125 W | 20-25 W |
| 125 W | 26-30 W |
| 150 W | 35-42 W |
2. I purchased CFL's but the light was cold and we didn't like it.
Technological developments in CFL's have come a long way in the last 5 years. You can now purchase warm colors, and dimmable light bulbs, which were not available before.3. What do I need to know to shop for fluorescent light bulbs, which have the least delay in turning on? What have the improvements been in CFLs over time in terms of how fast they light up?
The major improvement in CFLs resulting in quicker start-up time has been the introduction of electronic ballasts and improved starting methods. Ballasts, which control lamp current and provide the required start-up voltage, may be magnetic or electronic. Most early CFLs used magnetic ballasts. Electronic units are lighter, quieter, and more efficient. They have replaced magnetic ballasts in virtually all self-ballasted CFLs and in many pin-based CFLs.Some tips for buying CFLs with minimal or no delay:
- Make sure you are buying bulbs with an electronic ballast and instant-start technology.
- Look for the Energy Star label - Energy Star rated bulbs are required to have instant-start technology, i.e. time after switching on until full start averages 1 second or less.
- Stick with better known brands and don't be afraid to pay a little more. You will still save money over the life of the bulb and with higher end CFLs you will get a better product.
Do keep in mind that even with instant-start technology many bulbs still require a short warm-up period before they reach full brightness, which is why they may appear dim when first turned on. Compact fluorescent bulbs are best used in fixtures that are left on for longer periods of time, rather than in fixtures that are turned off and on frequently.
4. I have heard that it is not energy efficient to turn fluorescent lights on and off a lot- that it takes more energy to start them up than it does to leave them on for half an hour when you are not in the room. Is this true? What rule of thumb would you recommend for maximum efficiency? Is this also true of compact fluorescent bulbs?
It is a popularly held belief that fluorescent lights (including CFL's) use a "lot" of energy to get started, and thus it is better not to turn them off for "short" periods. There is an increase in power demand when a light is switched on, and the exact amount of this increase depends on the type of ballast and lamp. The ballast provides an initial high voltage for starting the lamp and regulates the lamp current during operation. This relatively higher "inrush" current lasts for half a cycle, or 1/120th of a second. The amount of electricity consumed to supply the inrush current is equal to a few seconds or less of normal light operation. Turning off fluorescent lights for more than 5 seconds will save more energy than will be consumed in turning them back on again. Therefore, the real issue is the value of the electricity saved by turning the light off relative to the cost of relamping a fixture. This in turn determines the shortest cost-effective period for turning off a fluorescent light.All types of lights have a nominal or rated operating life, which is the total number of hours that they will provide a specified level or amount of light. However, the operating life of all types of light bulbs is affected by how many times they are turned on and off. The more often they are switched on and off, the lower their operating life. The exact number of hours that switching lights on and off reduces the total operating life depends on the type of light and how many times it is switched on and off.
For most areas of the United States, a general rule-of-thumb for when to turn off a fluorescent light is if you leave a room for more than 15 minutes. In areas where electric rates are high and/or during peak demand periods, this period may be as low as 5 minutes. Fluorescent lights are more expensive to buy, and their operating life is more affected by the number of times they are switched on and off, relative to incandescent lights. Therefore, it is a cost trade-off between saving energy and money by turning a light off "frequently" and having to replace the bulbs "more" frequently. This is because the reduction in usable lamp life due to frequent on/off switching will probably be greater than the benefit of extending the useful life of the bulb from reduced use. By frequent we mean turning the light off and on many times during the day. Lighting manufacturers should be able to supply information on the duty cycle of their products. In general, the more energy-efficient a bulb/light is, the longer you can keep a light on before it is cost effective to turn it off.
5. I heard CFL's have mercury in them, is that true?
Yes, Recycling burnt-out CFL's is the best option. To find out if there are recycling options near you, call 1-800-CLEAN-UP for an automated hotline, visit www.earth911.org, or contact your local government agency in charge of household hazard waste. Should a bulb break, take these simple safety precautions for cleanup. First, open nearby windows to disperse any vapor that may escape. Carefully sweep up the fragments (do not use your hands) and wipe the area with a disposable paper towel to pick up all glass fragments. Do not use a vacuum. Place all fragments in a sealed plastic bag and follow disposal instructions above.Insulation:
1. Can insulation really make a difference in my heating bills?
Yes! As much as 15 percent of the energy you pay for escapes from your home through cracks and gaps in the walls and attic. Upgrading your attic insulation to 12 inches can reduce your heating costs by 30 percent.2. What does R-value mean?
R-value is a measure of thermal resistance "how well a material holds back heat. Insulation products are measured in R-value" the higher, the better.For example, a bare concrete foundation has an R-value of 1, while a fully-insulated attic has an R-value of 44.
3. How much insulation should we have in our attic?
The general rule for homes in regional DC is 12-15 inches of batt, blanket or loose-fill insulation. The exact answer depends on the size and age of your home, and what kind of insulation you'll be using.You can determine how much insulation your home needs by using the U.S. Department of Energy's ZIP-Code Insulation Calculator.
Weatherizing your home:
1. Can weatherizing really make a difference in my heating bills?
Yes! As much as 15 percent of the heating and cooling energy you pay for escapes from your home through cracks and gaps in the walls and attic.A $50 investment in weatherizing materials can help you save $150 on your heating bills - in just one winter!
2. How do I know where we need to weatherize?
An easy way to find all those air leaks is to hold a tissue near exterior doors, windows and electrical outlets - if drafts blow the tissue around, you know that area needs tightening.For a thorough air leak analysis, you can have a professional blower door test. A certified energy expert will use a pressurized fan to monitor the air flow in and out of your home. You'll get a detailed report showing exactly where energy leaks are occurring and how to fix them.