Can a programmable thermostat help me use less energy?
Yes. A programmable thermostat automatically adjusts your home’s temperature to your schedule, so you’re comfortable when at home and saving energy while away or sleeping. A programmable thermostat could be a good idea if you’re away from home on a regular basis, or want to automatically lower your energy use at night.
It saves energy while you’re away or asleep, and then brings your home’s temperature back to whatever level you desire by the time you return or wake up in the morning.
If you’re heating and cooling your home with an energy-efficient heat pump, a programmable thermostat will help you get maximum energy efficiency. Ask your heating and cooling dealer to install a programmable thermostat, and make sure it’s the type specially designed for your heat pump.
How do you insulate windows?
Single pane glass windows are virtually thermal holes in your walls. Having R-Values of roughly 1, they allow 19 times more heat to escape than an R-13 wall surrounding them. If you have lots of windows, insulating them could be one of your best energy improvements. However, keep in perspective how much you can improve them and still see through them. Adding another layer of glass raises their R-Value to just over 2, meaning now they are only losing 9 times as much heat as the insulated wall. Triple glazing can bring a window’s R-Value up to 3, but because of their expense they are only cost justified in severe climates. Storm windows can also be added to existing windows. They add a second layer of glass, halve the energy loss through the windows and often reduce infiltration through cracks in the old window casings. Of course, it would be better to have double-pane windows in the first place. Using double-pane windows to begin with brings three additional comfort advantages which some find more valuable than the energy savings. The first is the reduced noise provided by insulated windows. The second is less infiltration of dust and pollen. And the third is that insulated windows are warmer to the touch, which has a significant effect on body comfort. Because our bodies radiate heat toward cold surfaces even when they are several feet away, a cold window makes one feel colder.
How does a heat pump work?
A heat pump works like an air conditioner during the summer and reverses to become an air heater during the winter.
In the summer months, refrigerant is piped through the indoor coils, absorbs heat from the room air, and vaporizes. The cooled room air is then re-circulated throughout the house by a blower. The vaporized refrigerant flows into the compressor, which pumps the refrigerant to the outdoor coil, where it condenses back into a liquid by releasing its heat to the outdoor air. Air is circulated through the outside unit by a fan. The cooled refrigerant then flows back to the indoor coil, where the heat transfer cycle is repeated.
In the heating mode, the refrigerant flow is reversed, bringing heat inside from outdoors, essentially working like a conventional air conditioner in reverse. Cold refrigerant is piped through the outdoor coils, absorbing heat from the outside air. The refrigerant vaporizes and flows into the compressor, which pumps it to the indoor coil, where it condenses back into a liquid by releasing its heat to the indoor air. The refrigerant then flows back to the outdoor coils, where the heat transfer cycle starts again.
Like refrigerators, most heat pumps have defrost cycles that minimize frost buildup on the evaporator during the winter heating cycle. Defrost occurs automatically at pre-set time intervals. Defrosting works against the efficiency of the unit when it switches into defrost mode unnecessarily, wasting heating and cooling capacity. Microprocessor controls in some units prevent this from happening. Some controls even determine whether the heat pump or back-up heat is more economical at a particular outdoor air temperature and switch to that heating system.
How does an air conditioner work?
Refrigeration units, commonly known as air conditioners, are mechanical systems that remove heat and moisture from the air by passing it over a cold surface. When warm, moist inside air is blown across the surface of the unit’s cooling coil, the air temperature drops and the water vapor in it condenses making the air cooler and drier and therefore more comfortable. When the outside air is above 75°F, mechanical refrigeration is usually required to lower the inside temperature and humidity to make people feel comfortable. Refrigerating air for comfort inside the home, called air conditioning, is far more complicated than heating. Instead of using energy to create heat, air conditioners use energy to remove heat. The most common air conditioning systems use what is known as a vapor-compression cycle, similar to the one used by a refrigerator.
The primary difference is a refrigerator moves heat out of its interior and releases it to the surroundings, usually the kitchen, while air conditioners take heat from inside the house and release it to the outside environment.
Home air conditioners have compressors outside containing a fluid refrigerant, usually R-22. This refrigerant fluid can change back and forth between liquid and gas states at temperatures in the 40 to 50°F range. Just like water when it boils, as the refrigerant changes from a liquid to a gas, it absorbs heat, and when it changes back from a gas to a liquid, it releases heat. By changing state, refrigerants move heat from one place to another.
What is the best way to locate air leaks in a home?
The most rigorous way to locate duct leaks is with a blower door or similar analysis performed by a professional. This analysis measures the magnitude of your duct leakage and identifies its location. Some companies offer ductwork sealing services with a follow-up blower door check to ensure duct leakage has been reduced to acceptable levels. A blower door is a special instrument used to measure air leakage in a building shell and its ductwork. The equipment consists of a temporary door covering which is installed in an outside doorway and a blower which forces air into or out of the building. The blower door measures how leaky the building and ductwork are, and can be used to find the location of the major leaks. Without a blower door, finding the leaks in the ductwork can be difficult since the ducts are often in hard to reach areas such as the attic or crawl space and the leaks are usually hidden from view by duct insulation.
What is the best way to reduce cooling costs in the summer?
The best way to reduce the need for cooling during the hot summer months is by keeping the sun out of the home. Begin as far away from the house as possible with shade trees, trellises covered with vines, or awnings. Pay particular attention to east and west facing windows. The sun is low in the sky as it rises and sets allowing its rays to penetrate deep inside the home and making it tricky to keep out. When allowed to enter the home through windows, this solar radiation can cause the inside temperature to rise as much as 20°F on a hot day. The most effective way to shade the home’s east and west windows and walls is to plant tall trees or plant vines on horizontal trellises. Be sure to use deciduous trees and vines because their leaves provide shade in summer, but they drop them in winter when the solar gain is appreciated. Awnings wider than the windows can provide shade, but even they are ineffective when the sun is very low in the sky and can enter the home right under the awnings. To further protect the home, whenever possible, locate porches and garages on east and west walls for additional shading. Shading large areas that can either reflect or retain and reradiate heat into the home like concrete patios and driveways is also helpful. Most homes have roof overhangs that sufficiently shade the windows. When replacing windows, it is preferable to look for high-performance windows with low-E glazing. They look perfectly clear, yet block out a large percentage of unwanted solar radiation. As you move closer to the home, measures tend to become less effective and more expensive to install. Inside the home, solar gain through windows can be reduced by installing drapes with light-colored linings or blinds that can reflect sunlight. Vertical blinds are particularly effective on east- and west-facing windows. Also, choosing lighter colors for roofs and walls to reflect sunlight will reduce heat gain.
What advantages does a ductless split-system offer over room and central air-conditioners?
The advantages of ductless split-systems over room and central air-conditioners are: easy installation, quiet operation, versatility in zoning and design, and security. The split systems also eliminate the loss of cool air as it passes through the ductwork. A key advantage of split systems is their ease of installation. Hook-up requires only a three-inch hole (7.62 centimeters) in the wall for the conduit. Unlike with central air conditioning, you do not need ductwork. Since the compressor in most ductless split-systems is as much as 50 feet (15.24 meters) away from the indoor evaporator, it is usually possible to cool rooms on the front side of the house, while still hiding the compressor in a less conspicuous area. The compressor units also fit well on flat rooftops.
Ductless split-system air-conditioners operate relatively quietly, since the compressor is outside and the evaporator unit’s fan generally runs at a low speed. Variable speed high-efficiency fans are also available.
By providing zone cooling, ductless split-system air-conditioners save energy, since only the rooms that are occupied need to be cooled. A thermostat independently controls each zone. Therefore, operating costs are often lower than those of central systems that cool every room, whether it is in use or not. If you cannot afford to purchase an air conditioner for the whole house, you can also buy the system one zone at a time. A single outdoor unit controls from one to four zones, depending on the size of the unit.
When compared to other add-on systems, split-systems also provide better interior design options. The air handlers can be suspended from a ceiling, mounted flush into a drop ceiling, or hung on a wall. Floor-standing models are also widely available. Most indoor units are low-profile models, no more than seven inches (17.78 centimeters) deep, and come with decorative jackets. Most newer models come with a remote control unit as standard equipment. This allows the positioning of air-handling units high on a wall or suspended from a ceiling, without compromising convenience.
Unsecured room air-conditioners provide an easy entrance for intruders. Split- systems are more secure than window units since there is only a small hole in the wall.
What is a geothermal system?
Everyone knows its cooler underground in the summer and warmer underground in the winter. Geothermal systems take advantage of the earth’s constant temperatures to provide the highest efficiency available today. Special plastic piping is buried below the ground’s surface which allows heat to be transferred to and from the earth. Water is simply re- circulated to and from the underground piping where it is warmed by the earth in the winter and cooled by the earth in the summer. In order for any system to work properly, it must be sized, designed and installed correctly. Make sure your contractor is manufacturer-certified to install closed loop Geothermal systems.
What is the purpose of a home energy audit?
The purpose of an energy audit is to identify places in the home where energy is being wasted and prioritize the actions needed to fix them. You’ll start saving money on your energy bills as soon as you identify and fix energy wasters .The end result is intended to reduce the amount of energy the home needs to operate and keep occupants comfortable. Energy audits range from simple walk-throughs you can do yourself to more elaborate services performed by trained professionals. Which is right for you will depend on your situation, abilities and interest level.
Why is it a good idea to invest in a heat pump?
The most advanced and efficient heating and cooling system available today, a heat pump is the most economical way to keep your home comfortable year-round. The technologically advanced heat pump keeps your home warm in the winter and cool in the summer—with one amazing piece of equipment. It’s also a wise energy investment that can result in major savings on monthly energy bills for many homeowners.
You also can’t beat a heat pump for durability. In fact, heat pumps last an average of 20 years in the Southeast United States.
Heat pumps also provide added design flexibility when building a home. Since there are no flames or fumes, you won’t have to add flues or vent pipes that waste valuable closet and storage space. And because there are no flues, you’ll have more choices in where to locate the indoor part of your heat pump system.
Will a ceiling fan help me save energy and money?
Yes. Ceiling fans move air across the surface of the skin, thereby making people feel up to six degrees cooler. Increase your thermostat’s setting by two degrees and use your fan to lower energy costs by up to 8% over the course of the air conditioning season. Some ceiling fans offer reversible operation; they can blow down in summer when the breeze will create a cooling effect, and up in winter to circulate warm air that has risen to the ceiling. This feature is particularly advantageous in rooms with high ceilings that trap warm air during the heating season.
While operating, losses from the motor actually heat the space in which they run; therefore, they should only be on when someone is there to appreciate their cooling effect. When no one is in the room, keep ceiling fans off. Ceiling fans are usually mounted at the center of the room where the light fixture would normally go. For this reason, they often contain their own lighting fixture just below the fan blades. It is important to keep lighting below the blades because lights above them will appear to flicker psychedelically when the fan operates. If you own or purchase a fan with a lighting fixture, optimize its efficiency by using ENERGY STAR®-qualified compact fluorescent light bulbs (CFLs). They consume three-quarters less electricity, generate 75%* less heat and last up to 10 times longer than standard incandescent lighting.
* Source: ENERGY STAR® -www.energystar.gov