Modern heat pumps offer better-than-ever comfort at lower-than-ever costs. Industry studies confirm that heat pumps save money and provide true comfort in all seasons, while conserving natural resources. Unlike a conventional furnace that “combusts” natural gas or propane inside your home, an electric heat pump acts as a heat transfer machine. In winter, it absorbs heat from either outside air or the ground, multiplies that heat and moves it into your home. In the summer, the heat pump works exactly like an air conditioner, moving heat out of your home to cool it. Since a heat pump is powered by electricity, it’s a good way to beat the high cost of heating with natural gas.
Heat pump air supply temperatures range from 95 degrees to 110 degrees — some 20 to 35 degrees higher than room temperature. Air from registers may seem cooler than expected but temperatures throughout the room remain more constant. With other systems, air enters the room warmer but quickly collects near the ceiling. Since a heat pump delivers air closer to desired room temperatures, the air rises more slowly, making more heat available to people—not ceilings!
In summer, a heat pump delivers cool, dehumidified comfort like any central air conditioner. And because newer models are highly efficient, they save you money on operating costs. That’s especially true if you’re replacing an older air conditioner.
Clean, Safe, Healthy.
Instead of burning fossil fuel, heat pumps collect heat from the air or the ground. There are no flues, flames or exhaust pollutants, and no need for carbon monoxide sensors. And since no combustion occurs, the inside of your home stays cleaner, safer and healthier. During operation, the system recirculates the air, filtering away dust and airborne particles making air healthier for everyone, particularly those who suffer from allergies or asthma. Since heat pumps don’t dry the air like furnaces, you’ll reduce dry skin and dry throat problems in the winter and help protect fine wood furnishings.
Air Source Heat Pumps
Instead of creating heat, air source heat pumps transfer energy from the air. This quiet and efficient movement of heat into and out of your home naturally provides warmth and comfort. There are two common types of air source heat pumps: all-electric and dual-fuel. Installation, operation and efficiencies vary from system to system.
All-Electric Air Source Heat Pump Systems.
These systems combine an air source heat pump with supplemental electric resistance heat. In summer, the heat pump works like a central air conditioner, removing heat and humidity from your home and moving it outside. In the winter, it reverses the process, absorbing heat from outside air, multiplying it and then transferring it inside. Although winter temperatures feel cold to the skin, at zero degrees air contains 82 percent of the heat available when it’s 100 degrees outside. Heat transfer occurs when the temperature of the refrigerant in the heat pump’s outside coil is lower than the temperature of the outdoor air.
Dual-Fuel Air Source Heat Pump Systems.
These systems pair a heat pump with agas or propane furnace to provide back-upheating during extremely cold conditions.
Dual-fuel systems take advantage of the efficiencies of both units. Heat pumps are most efficient in moderately cold weather
down to about 30 degrees, with some models going down to as low as 17 degrees! Gas furnaces reach optimum efficiency in extreme cold. Working in tandem, the units take turns operating only at the temperatures where maximum efficiency is achieved. Many dual-fuel systems allow you to select the temperature at which the switching between units takes place. Usually that’s when outdoor temperatures are around 30 degrees. The heat pump connects to a furnace like a central air conditioner. Dual-fuel systems are ideal for new and existing homes, helping increase comfort and lower operating costs. Their combined efficiency makes them a leading choice for thousands of homeowners. Remember, with a dual-fuel heat pump system you have the option of selecting the most cost-effective heating source. Talk with your dealer about how to set your system controls to take advantage of the best energy prices.
Geothermal Heat Pumps:
Good for Your Budget & the Planet
Geothermal Heat Pump (GHP) systems, also called “ground source” heat pumps, work using a grid of high density polyethylene (HDPE) pipe buried beneath the surface. Known as a ground loop heat exchanger, the grid system connects to a high-efficiency heat pump located inside the home. Water circulating through the ground loop absorbs the Earth’s heat in the winter, where it is multiplied by the heat pump and transferred inside to heat the home - even when outside air is below freezing! In the summer, the system’s operation reverses, removing heat from the home and transferring it to the ground loop and, in turn, back to the Earth. And, because ground temperatures typically remain constant between 55 and 65 degrees, these systems work much more efficiently than air source heat pumps.
Ground Loop Heat Exchangers.
Geothermal Heat Pump heat exchangers are available in either vertical or horizontal configurations. Their best layout depends on the available land and other features of the building lot. For example, vertical loops are more suitable for small areas, where there is rock or the terrain prohibits a horizontal system. Highly reliable HDPE plastic pipe is inserted vertically in 150- to 250-foot deep bored holes. In horizontal systems, HDPE piping is buried in 5- to 6-foot deep trenches across a wide area of land. Other horizontal configurations include slinky and pond loops. Another loop type is direct exchange (DX). These systems utilize refrigerant copper tubing placed horizontally underground. As refrigerant from the heat pump’s compressor is pumped through the DX loop, heat is transferred directly through the copper to the Earth.
Domestic Water Heating.
Most manufacturers incorporate a “desuperheater” heat exchanger option capable of providing up to 75 percent of your family’s hot water needs — nearly free! A desuperheater is a small, auxiliary heat exchanger that uses superheated gases from the heat pump’s compressor to heat water for domestic uses. This hot water then circulates through a pipe to the home’s normal water heater tank or an added pre-heat tank. In summer, when the GHP system is in the cooling mode, the desuperheater simply uses excess heat that would otherwise be transferred to the ground loop.
The underlying advantage of GHP systems is their use of the Earth’s renewable “stored solar” energy—thus the conservation of valuable natural resources used to provide home comfort. In fact, the U.S.Department of Energy (DOE) and the Environmental Protection Agency (EPA) rate GHPs as the most efficient,environmentally friendly heating and cooling systems available today for residential and commercial buildings.And, studies have demonstrated operation cost savings ranging up to 70 percent.GHP systems not only provide environmental and operational savings, but also provide benefits in other ways.There is no noisy outdoor equipment. They are highly reliable, require little maintenance, and are built to last for
decades. And since a GHP provides warmer conditioned air in the winter, up to 110 degrees, you’ll stay more comfortable — even on the coldest days! A geothermal system is an investment that will add considerably to the value of your home.
Choosing Your Heat Pump
Heat pumps are adaptable to a wide variety of uses and needs. Whether building a new home or replacing your old system, let your need determine whether you choose an all-electric, dual-fuel or geothermal heat pump system. When shopping for a heat pump, look for industry efficiency ratings commonly referred to as SEER and HSPF:
• Seasonal Efficiency Energy Ratio (SEER) is the rating used to distinguish the cooling efficiency of an air conditioner or heat pump. The higher the SEER rating the more efficient the machine. For a unit manufactured today, the minimum efficiency standard is 13 SEER. Multistage air source heat pumps are available up to 24 SEER. So for optimum summer savings consider units with a 15 SEER or higher.
• Heating Seasonal Performance Factor (HSPF) is the efficiency rating used to identify the heating efficiency of an air source heat pump. HSPF ratings commonly range from 6.5 through 11. Again, the higher the number the more efficient the system’s heating will be. Use industry standard SEER and HSPF ratings to compare various brands and models of heat pumps. And remember, higher numbers mean higher efficiency, as well as lower operating costs.
Look for the Energy Star®
ENERGY STAR® is a government and industry partnership that offers consumers and businesses energy efficient product labeling, making it easier to save money while protecting the environment for future generations. Labeling is provided on more than 50 product categories, including air source and geothermal heat pumps. To earn the ENERGY STAR label, heat pumps must meet strict energy efficiency guidelines established by the EPA and the DOE. ENERGY STAR units have higher SEER and HSPF ratings. This makes them about 12 percent more efficient than new standard models and up to 50 percent more efficient than what may be found in existing homes.
Keep your system in top-shape with regular maintenance. As with other systems, heat pumps should receive periodic
maintenance to ensure dependable, economic operation and long life. The maintenance schedule for heat pumps is similar to a central air conditioner. Inspect your system regularly. Keep filters, air passages and outdoor coils clear of obstructions, such as dirt, leaves, shrubbery and trash.
The refrigerant commonly used in residential air-conditioning and heat pump units is a hydrochlorofluorocarbon (HCFC), known as R-22. To protect the stratospheric ozone layer, the U.S. is phasing out the use of R-22 and other ozone-depleting chemicals. In 2010, production and import of R-22 will be curtailed and, in 10 years, will no longer be available. After 2020, only reclaimed, recycled R-22 will be available. Cooling equipment that contains R-22 will continue to be manufactured until 2009. Supplies of R-22 will become limited after 2010. Today, the most common alternative to R-22 is R-410A, a non-ozone depleting refrigerant blend. All major U.S. manufacturers have selected R-410A as the long-term choice for new equipment. Do your part for the environment; ask your dealer about heat pumps designed with R-410A.
Utility Rebates and Tax Credits
There are many utility rebates that may be available when upgrading your home with a heat pump, depending on your utility company. There may also be tax credits available. To learn about the details on tax credits, talk with your tax professional or visit http://energy.gov/savings/residential-energy-efficiency-tax-credit