SEER, AFUE & more...

helping unwind the terminology...

SEER (air conditioners)

The efficiency of air conditioners are often, but not always, rated by the Seasonal Energy Efficiency Ratio (SEER). The higher the SEER rating, the more energy efficient is the air conditioner. The SEER rating is the Btu of cooling output during a simulated, typical cooling-season divided by the total electric energy input in watt-hours (W·h) during the same period. [1]

SEER = BTU ÷ W·h

For example, a 5000 Btu/h air-conditioning unit, with a SEER of 10, operating for a total of 1000 hours during an annual cooling season (e.g., 8 hours per day for 125 days) would provide an annual total cooling output of:

5000 Btu/h × 1000 h = 5,000,000 Btu

With a SEER of 10, the annual electrical energy usage would be about:

5,000,000 Btu ÷ 10 = 500,000 W·h

This is equivalent to an average power usage during the cooling season of:

500,000 W·h ÷ 1000 h = 500 W

The average power usage may also be calculated more simply by:

Average power = (Btu/h) ÷ (SEER, Btu/W·h) = 5000 ÷ 10 = 500 W

US Government SEER Standards

Today, it is rare to see systems rated below SEER 9 in the United States because aging, existing units are being replaced with new, higher efficiency units. The United States now requires that residential systems manufactured after 2005 have a minimum SEER rating of 13, although window units are exempt from this law so their SEERs are still around 10.[3] Substantial energy savings can be obtained from more efficient systems. For example by upgrading from SEER 9 to SEER 13, the power consumption is reduced by 30% (equal to 1 - 9/13). It is claimed that this can result in an energy savings valued at up to US$300 per year depending on the usage rate and the cost of electricity.

With existing units that are still functional and when the time value of money is considered, most often retaining existing units rather than proactively replacing them is the most cost effective. Maintenance should be performed regularly to keep their efficiencies as high as possible.

But when either replacing equipment, or specifying new installations, a variety of SEERs are available. For most applications, the minimum or near-minimum SEER units are most cost effective, but the longer the cooling seasons, the higher the electricity costs, and the longer the purchasers will own the systems, incrementally higher SEER units are justified. Residential split-system ACs of SEER 18 or more are now available, but at substantial cost premiums over the standard SEER 13 units.

AFUE (heaters)

A central furnace or boiler's efficiency is measured by annual fuel utilization efficiency (AFUE). AFUE is a measure of how efficient the appliance is in using fossil fuel (gas or oil) or electricity (for an electric furnace) over a typical year of use.

An all-electric furnace or boiler has no flue loss through a chimney. The AFUE rating for an all-electric furnace or boiler is between 95 and 100 percent. The lower values are for units installed outdoors because they have greater jacket heat loss.

The efficiency of manufactured furnaces is governed by the National Appliance Energy Conservation Act of 1987 and regulated by the U.S. Department of Energy. The minimum allowed AFUE rating for a noncondensing, fossil-fueled, warm-air furnace is 78 percent; the rating for a fossil-fueled boiler is 80 percent; and the rating for a gas-fueled steam boiler is 75 percent. A condensing furnace or boiler condenses the water vapor produced in the combustion process and captures the heat released from this condensation. The AFUE rating for a condensing unit can be much higher (by more than 10 percentage points) than a noncondensing furnace. Although a condensing unit costs more than a noncondensing unit, the condensing unit can save you money in fuel costs over the 15- to 20-year life of the unit.

HEAT PUMP info...

Selecting a Heat Pump

Every residential heat pump sold in this country has an EnergyGuide 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 ratio of the seasonal heating output in Btu divided by the seasonal power consumption in watts. Cooling efficiency is indicated by the seasonal energy efficiency ratio (SEER), which is the ratio of the seasonal heat removed in Btu per hour to the seasonal power consumption in watts.

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. In general, the higher the SEER, the higher the cost. 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=12) 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 14 and 18.

To choose an air-source electric heat pump, look for the ENERGY STAR label, which is awarded to those units with SEERs of 12 or greater and HSPFs of 7 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 EnergyGuide label for an efficiency of 12 SEER/7HSPF 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 will begin 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 7.6 bels 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.

 

Haddon Brand!

Haddon Heating and Cooling begins carrying its own brand!

We are excited to announce that Haddon Heating and Cooling now carries its own brand of air conditioning and heating products. The products have the highest efficiency ratings, are of the highest quailty and carry the best warranties in the industry. Additionally, with our products, customers can expect every Haddon service technican to know their systems inside and out - INSTANT EXPERTISE.

Call us today to find out more about this new line of products and how Haddon Heating and Cooling can provide you with excellent service and products at competitive prices.