Dallas Heat Pumps

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Heat Pumps

An air-source heat pump can provide efficient heating and cooling for your home, especially if you live in a warm climate like Dallas, TX. When properly installed, heat pumps can deliver one-and-a-half to three times more heating energy to a home than the electrical energy it consumes. This is possible because a heat pump moves heat rather than converting it from a fuel, like in combustion heating systems.

Although heat pumps can be used in nearly all parts of the United States, they do not generally perform well over extended periods of sub-freezing temperatures. In regions with sub-freezing winter temperatures, it may not be cost effective to meet all your heating needs with a standard air-source heat pump.

How Heat Pumps Work

A heat pump refrigeration system consists of a compressor and two coils made of copper tubing (one indoors and one outside), which are surrounded by aluminum fins to aid heat transfer. In the heating mode, liquid refrigerant in the outside coils extracts heat from the air and evaporates into a gas. The indoor coils release heat from the refrigerant as it condenses back into a liquid. A reversing valve, near the compressor, can change the direction of the refrigerant flow for cooling as well as for defrosting the outdoor coils in winter.

When outdoor temperatures fall below 40°F, a less-efficient panel of electric heating coils, similar to those in your toaster, kicks in to provide indoor heating. This is why air-source heat pumps aren't always very efficient for heating in areas with cold winters. Some units now have gas-fired backup furnaces instead of electric resistance coils, allowing them to operate more efficiently in colder climates.

The efficiency and performance of today's air-source heat pumps is one-and-a-half to two times greater than those available 30 years ago. This improvement in efficiency has resulted from technical advances and options such as these:

• Thermostatic expansion valves for more precise control of the refrigerant flow to the indoor evaporator coil
• Variable speed blowers, which are more efficient and can compensate for some of the adverse effects of restricted and undersized ducts, dirty filters, and dirty coils
• Improved evaporator and condenser coil designs
• Improved electric motor and two-speed compressor designs
• Copper tubing, grooved inside to increase surface area

Most central heat pumps are split-systems-that is, they each have one coil indoors and one outdoors. Supply and return ducts connect to a central fan, which is located indoors.

Some heat pumps are packaged systems. These usually have both coils and the fan outdoors. Heated or cooled air is delivered to the interior from ductwork that protrudes through a wall or roof.

Selecting a Heat Pump

Every residential heat pump sold in this country has an Energy Guide Label, which features the heat pump's heating and cooling efficiency performance rating, comparing it to other available makes and models.

Heating efficiency for air-source electric heat pumps is indicated by the heating season performance factor (HSPF), which is the total space heating required during the heating season, expressed in Btu, divided by the total electrical energy consumed by the heat pump system during the same season, expressed in watt-hours.

Cooling efficiency is indicated by the seasonal energy efficiency ratio (SEER), which is the total heat removed from the conditioned space during the annual cooling season, expressed in Btu, divided by the total electrical energy consumed by the heat pump during the same season, expressed in watt-hours.

The Heating Seasonal Performance Factor (HSPF) rates both the efficiency of the compressor and the electric-resistance elements. The most efficient heat pumps have an HSPF of between 8 and 10.

The Seasonal Energy Efficiency Ratio (SEER) rates a heat pump's cooling efficiency. Higher seer ratings cost more to purchase, however, the energy savings can return the higher initial investment several times during the heat pump's life. Replacing a 1970s vintage, central heat pump (SEER = 6) with a new unit (SEER=13) will allow the use of half the energy to provide the same amount of cooling, cutting air-conditioning costs in half. The most efficient heat pumps have SEERs of between 13 and 21.

To choose an air-source electric heat pump, look for the ENERGY STAR® label, which is awarded to those units with SEERs of 13 or greater and HSPFs of 8 or greater. If you are purchasing an electric air-source heat pump and are uncertain whether it meets ENERGY STAR qualifications, look on the bright yellow Energy Guide label for an efficiency of 13 SEER/8HSPF or greater. For units with comparable HSPF ratings, check their steady-state rating at -8.3 degrees C, the low temperature setting. The unit with the higher rating will be more efficient.

Consider buying a heat pump with an HSPF of at least 7.7. In September 2006, the U.S. Department of Energy began enforcing a new standard that will require central heat pumps to have a minimum rating of 7.7 HSPF. In warmer climates, SEER is more important than HSPF; in colder climates, focus on getting the highest HSPF feasible.

These are some other factors to consider when choosing and installing air-source heat pumps:

• Select a heat pump with a demand-defrost control. This will minimize the defrost cycles, thereby reducing supplementary and heat pump energy use.
• If you're adding a heat pump to an electric furnace, the heat pump coil should usually be placed on the cold (upstream) side of the furnace for greatest efficiency.
• Fans and compressors make noise. Locate the outdoor unit away from windows and adjacent buildings, and select a heat pump with an outdoor sound rating of 76 decibels or lower. You can also reduce this noise by mounting the unit on a noise-absorbing base.
• The location of the outdoor unit may affect its efficiency. Outdoor units should be protected from high winds, which can cause defrosting problems. You can strategically place a bush or a fence upwind of the coils to block the unit from high winds.

If you are interested in finding out more about Heat Pumps, you can read the Frequently Asked Questions below, or feel free to contact. We both install and repair all brands of Heat Pumps.

Frequently Asked Questions

Will a Heat Pump save energy in my home?

Heat Pumps offer the most significant energy savings where:

• Natural gas is not available as a fuel,
• Winter temperatures are mild, and
• The home is well-insulated.

If natural gas is available to you, we will probably recommend a conventional air conditioning and furnace system. But if your home is served by electric heating coils only, a Heat Pump can be a major energy-saver.

Will I also need a conventional central heater if I install a Heat Pump?

Yes, though you're primary source of heat will be the Heat Pump. When temperatures dip towards freezing, a conventional electric heater will be needed to supplement the Heat Pump. In summer, however, the Heat Pump will be able to supply all you're cooling.

How does a Heat Pump work?

Just like conventional air conditioning, in the summer a Heat Pump draws heat from indoors and rejects it to the outdoors. In winter, the direction of the refrigerant flow in a Heat Pump is reversed. In winter, the Heat Pump draws heat from the outdoors and brings it into your home.

It may seem that in winter there's not much outdoor heat to draw from. But at temperatures above the 30°- 45° F range, Heat Pumps are very efficient at squeezing heat from outdoor air. In this way, Heat Pumps both cool your home and heat it. And in many cases, they do so more efficiently than a conventional heating and air system.

For more on this or any of our other products and services, please contact us. Don't forget to ask us about our Safety & Reliability Agreements and Safety and Efficiency Agreements.

Warranty Information

Beginning May 1 2009, Registered Limited Warranty terms are available if the product is registered within 60 days of installation. Registration can be completed either online at Trane.com or by calling 800-554-6413. Trane's Registered Limited Warranty terms include:

• 10 Year limited warranty on compressor
• 10 Year limited warranty on outdoor coil
• 10 Year limited warranty on internal functional parts
• The ten year Functional Parts Limited Warranty extends to the indoor gas furnace, evaporator coil, air handler and thermostat when installed as part of a complete XR comfort system. An XR comfort system includes an AHRI certified matching Trane outdoor XR unit, indoor unit and thermostat installed at the same time.
• If the product is not registered within 60 days of installation Trane's Base Limited Warranty terms will apply.
• Optional Extended Warranties available. Extended Warranties can pay for labor and other costs not covered by manufacturer's limited warranty.
• Ask us for full warranty information at time of purchase. Warranties are for residential use only, some exclusion's may apply.

Call us today at (972) 276-2544. We are your Dallas heat pump contractor.