What size system do I need for my home?

It is important that new or replacement equipment is not sized by "Rule of Thumb" or by duplicating the existing equipment capacity. The only accurate way to determine the correct capacity of heating and air conditioning equipment for your home is to have a load calculation performed on your home. There is a specific method available to all dealers to do this calculation. This will give your dealer the heat gain and heat loss design data for your home. These figures can then be used to select the appropriately sized air conditioning or heating system for your home, based on equipment-performance data.

How do I verify the size of my air conditioner or heat pump?

The capacity in tons of a Trane outdoor unit can be determined by dividing the 7th and 8th digit of the model number by 12, such as 4TTX4036A1000A - 36 divided by 12 = 3 tons.

(This is only for Trane models. Other companies use a different method based on their model number nomenclature.)

What is a heat pump?

The heat pump is an air conditioner that reverses the process of removing heat from the inside of the house in summer to absorbing the heat from outside air and moving it inside in winter. It is effective by itself down to temperatures around 25 to 30 degrees Fahrenheit. At that point, either a gas furnace or an air handler with supplemental electric heat will kick in and help heat your home. The Auxiliary Heat light on your thermostat will light. The heat pump will continue to operate along with the electric auxiliary heat. It will shut off when a gas furnace is energized. Emergency heat is a manual override option in the event your heat pump needs service.

What is the purpose of Auxiliary Heat?

Under normal operating conditions, the auxiliary heat is brought on automatically by the thermostat when the indoor temperature drops during heat pump operation. There are also times during cold, wet weather when the outdoor coil may ice up and your heat pump will go into a defrost cycle. This is nothing more than reversing the process back to cooling mode. Cooling mode makes the outdoor coil hot and melts any ice. The defrost cycle should only last a few minutes and then return to heating mode. During the defrost cycle, your comfort system is in cooling mode and the supply air is cool. To offset this cool air, the auxiliary heat will be energized during defrost. A mist or fog may be visible from the outdoor unit during defrost.

Is a Heat Pump the Right Choice for My Home?

The heat pump is effective in many geographies. In all electric applications, the heat pump may consume less energy than an electric furnace or air handler using resistance heat. Why? Because it can deliver the same amount of BTUs as electric heaters using less electrical input than the electric heat. In moderate climates the savings that natural gas yields may not be as advantageous as in colder climates, since there is less frequent use of the furnace in milder climates. Of course, the heat pump can be matched with a gas furnace where preferred. The heat pump can operate in the milder temperatures when the gas furnace may tend to short-cycle.

To determine which system would serve your specific needs best, we can perform a Load Calculation on your home and then estimate the cost of operation for the different combinations of equipment.

What Is an Air Handler?

The major components enclosed in an air handler's cabinetry are the blower and motor, controls, heater compartment, and an evaporator coil. This is why it is also sometimes referred to as a fan coil. A standard air handler, like the single stage furnace, delivers the same amount of airflow no matter what the temperature inside. Trane's variable-speed air handler has Comfort-R Enhanced mode, like our variable-speed gas furnace, allowing the coil to cool down quickly and the blower to slowly ramp up and ramp down or to operate at 50 percent of the cooling air speed in the FAN ON position. This provides greater humidity control, quieter operation, maximum air circulation, temperature distribution, and air filtration for greater control of your home's indoor environment.

What Do All Those Rating Numbers Mean?

The federal government requires all air conditioning and heating equipment to be rated for efficiency. The higher the rating, the more efficient the model.

Gas furnaces are rated for AFUE (Annual Fuel Utilization Efficiency). This defines the amount of heat used to warm your home from the burned fuel. A 90% furnace will use 90% of the available heat to heat your home. 10% of the heat is vented outdoors. Many older gas furnaces are only 60% efficient. The other 40% is vented outdoors. You can see that a new high-efficiency furnace will require much less fuel to heat your home.

For air conditioning, the rating is SEER (Seasonal Energy Efficiency Ratio). This rating is based on general design criteria such as the compressor and outdoor coil. SEER ratings are for comparison purposes only, so that homeowners will know how they can compare different brands of products with similar efficiency ratings. The rating for the outdoor unit will reference a general efficiency range, such as 14 SEER. The actual efficiency rating for a specific system will depend on the combination of the outdoor unit and the indoor coil these ratings are available from your dealer and the Air-Conditioning and Refrigeration Institute's Energy Guide. A variable-speed indoor blower unit will increase the efficiency rating of the system, as well.

Heat pumps are rated by SEER for cooling efficiency and by HSPF (Heating Seasonal Performance Factor) for heating efficiency. As with other ratings, the higher the HSPF, the less energy it will take to warm your home.