The Annual Fuel Utilization Efficiency (AFUE) is the most widely used measurement of a boiler or furnace’s heating efficiency. The AFUE refers only to the unit’s fuel efficiency (i.e. natural gas, propane or heating oil), not its electricity usage.

The higher the AFUE, the better. In the U.S., new boilers and furnaces all have to have an AFUE of 78% or higher now. Some high-end units top 90 % AFUE.

The Energy Efficiency Rating (EER) of a particular cooling appliance is the ratio of output cooling (in BTU/hr) to input electrical power (in watts) at a given operating point. This differs from the SEER, since the SEER’s measurement is for a typical cooling season. EER is generally calculated using 95 ̊ Fahrenheit outside temp and an inside temperature of 80 ̊ Fahrenheit (which is actually return air) with 50% relative humidity.

British Thermal Unit (BTU) is a measure of heat energy. One BTU corresponds to the amount of thermal (heat) energy required to heat one pound of water 1 degree Fahrenheit.

In practical use, HVAC professionals use BTUs to measure the cooling capacity of an air conditioning unit. The higher the BTU measurement, the more powerful the air conditioner.

Seasonal Energy Efficiency Rating (SEER) measures air conditioning and heat pump cooling efficiency, which is calculated by the cooling output for a typical cooling season divided by the total electric energy input during the same time frame.

A higher SEER rating means greater energy efficiency. It is a rating that the government has set as a guideline for homeowners to understand how efficient their system is compared to others. SEER is displayed as the number of BTUs per watt. The more BTUs per watt, the less it will cost to run the cooling system.

Air conditioners manufactured after January 2006 must be a minimum 13 SEER, while 8 SEER was predominant in the mid-1980s. In 1992, 10 SEER became the first federally mandated minimum efficiency for residential split systems, while 9.7 SEER was the mandated minimum for single package systems in 1993.

North American Technician Excellence (NATE), founded in 1997, is the country’s largest nonprofit certification organization for technicians in the heating, ventilation, air conditioning and refrigeration trades.

NATE offers certification tests for installation and/or service in one or more specialty areas. Most NATE certifications last five years, and to meet the requirements for recertification requires 60 continuing education hours in one’s specialty area. If your air conditioning service technician is NATE certified, it shows he or she cares about continuing education in a field where technology is growing and changing.

Simply the Best is committed to hiring NATE-certified technicians and making sure their certification stays active. This helps us achieve our mission – to make sure every repair and installation is done right… the first time.

Heat pumps manage heating and air conditioning all in one system using a special valve in the refrigeration piping, which allows the refrigeration cycle to be operated in reverse. This reversing valve controls which way the refrigerant is going to flow.

On air conditioning mode, the heat pump’s indoor (evaporator) coil is cold and the outside (condenser) coil is hot. On heating mode, the reversing valve switches the flow of refrigerant and the inside coil now becomes hot and the outside coil becomes cold. Heat pumps are a great way to get heating and cooling all out of one unit, rather than needing to have two separate appliances.

Here are a few questions to ask yourself to determine whether you want to repair or replace your AC unit:

• How old is my existing system?
• What exactly is its problem?
• How much is the repair going to be?
• What condition is the existing system in?

There are many considerations, but those questions are a great starting point as to making a decision you are going to be comfortable with when it’s all said and done.

A general rule of thumb is:

• Repair – if your system is less than 12 years old and the repairs are less than $400
• Replace – if your system is 12 years or older and the repairs are more than $400

To further elaborate, if your utility bills are going up faster than inflation would normally dictate, your older, inefficient heating and air conditioning system may be outdated to the point where it is now costing you money. Even if your air conditioner is only 10 years old, you may save significantly on your cooling energy costs by replacing it with a newer, high-efficiency air conditioner. The higher the SEER specification, the more efficiently the equipment is going to operate.