Common Sense Energy Savings

Common Sense Energy Reducing Techniques and Processes.

By Jules Williams Associate Member ASHRAE Building Analyst Professional.

At this time of ever increasing energy prices, we are saturated with sales people and companies who are determined to reduce our energy costs. Occasionally we find our selves at the mercy of these sales gimmicks per chance we may stumble upon a process or device that will actually reduce our energy bill.

Air-conditioning remains the largest and most costly component of our energy bill. Reducing energy associated with air-conditioning operation has been a concern since the introduction of air-conditioning. Today, air conditioning operation expense is a hardship to some and a burden to many.

The air-conditioning industry recently introduced higher SEER air-conditioners to meet regulatory concerns for more efficient energy consumption. In this article we will examine the SEER and its impact on the cost we pay for electricity, used to operate air-conditioning.

The Seasonal Energy Efficiency Ratio (SEER) is a combination of the Energy Efficiency Ratio (EER) and the coefficient of performance (COP); Both SEER and EER are used as standard bench marks for air-conditioning. The higher the EER value, the more efficient the machine.

The EER is the rated cooling capacity of a unit in Btu/h divided by the electrical power in watts. The SEER is similar to the EER .It is computed in the same way, but the wattage is adjusted to be more realistic. The SEER system uses the actual wattage. When a unit starts, it draws lock rotor amps. Therefore more power is consumed during startup compared to when the unit is operating.

This is where the SEER becomes interesting; we will now evaluate the formula for calculating the SEER.

The SEER is the total cooling accomplished by a unit during its normal annual usage, divided by the total electric energy input in watt-hours. The formula is:

Sum of BTU/H (cooling) outputs / Sum of all watt-hour inputs at all test conditions.

Like I describe previously the SEER is the seasonal energy efficiency for air-conditioners based on three tests. All three tests are based on 80 degrees oF indoors and 82 degrees out doors.

The first test is conducted using high indoor humidity, the second dry indoor humidity and the third under dry conditions, while cycling the unit on for six minutes then off for 24 minutes. This test is very suspect to various climates.

I provide the above information to highlight the complication associated with SEER and the ease with which industry and sales people are able to have us replace our 10 SEER equipment with SEER rating no less than 13. A 13 SEER unit is supposed to improve the cost for operating an air conditioner over a 10 SEER system.

The  air-conditioning sales people use the line that you are paying too much to operate your 10 SEER unit and proposes to upgrade to 13 SEER, which is the standard air-conditioning rating today, the sales pitch does not stop there; the  pitch is for 15 to 21 SEER and higher in-order to maximize savings.

I am interested in SEER and its relationship to energy savings that is why I purchased a 13 SEER to replace my 10 SEER unit. Like a parrot I rehearsed the justification to myself, lower operating cost. First I tested my unit under all conditions, measuring all parameters. I purchased a fluke data logger to store all the comparative data I needed in order to evaluate my new unit. I was surprised to find that the amps of my new unit was identical to the old unit, and since I paid for volts * Amps * PF, I expected to see a significant reduction in amps.

After several evaluations of the new unit and comparing the results to that of the old unit I concluded that SEER alone was not going to provide me with energy savings. Be weary of any one who wants you to increase the SEER of your unit with the excuse that you are paying too much for electrical energy.

Many energy experts agree that sealing residential duct work gives the highest pay back for homes and light commercial businesses it provides for an attractive pay back and greatly improves health concerns, indoor comfort and durability of many house hold items After years of research, three general process have been proven to provide the biggest return in home energy improvements for home owners all pertaining to duct work improvement.

1. Seal the duct.
2. Place ducts in un-vented attics and crawl spaces.
3. Place the ducts in the air-conditioned envelope.

Supply Duct leakage can occur in the supply or return duct or at the furnace or air-handler. Supply air leaks usually create negative pressure in the air-conditioned envelope. This condition attracts polluted outside air to enter the air- conditioned envelope. Other problems associated with negative pressure are:

1. Back drafting of combustible devices such as water heaters and furnaces
2. Introduction of out door contaminants into the indoor environment
3. Introduction of out door particles.
4. Poor indoor comfort with regards to dust and volatile organic compounds.
5. High operating cost
6. Reduced material life.

Return duct leakage produces similar ill effects and compares well with supply duct leaks.

Depressurizing tests of buildings reveal that at 25 pa. Sealing with fiberglass and mastic can reduce leaks to less than 5% of fan delivery capability. This computes to between 25 and 35% of measurable saving on energy use.

Energy reduction is attractive for providing savings for operating homes and businesses. Installing high SEER without regard for proper design and installation is unfortunate for the industry and a disregard for the customer.

I am not a believer of SEER and its influence on unaware customers with no information to enable them to make intelligent decisions when it comes to purchasing HVAC equipment. No company provides before and after data to justify their sale.

Any process that cannot be readily measured for benefits, while leaving opportunities for miss conclusions at high costs to suppliers and customers should be evaluated closely.

EER on the other is easily measured and decisions can be readily applied based on the results. EER represents the Energy Efficiency Ratio and is the relationship of the BTUH / divided by the unit electrical in watts. It should however be noted that EER changes as the weather conditions between indoor and out door changes.

Other installation concerns such as duct sizing, duct sealing, equipment selection, refrigerant line sizing and installation and general installation practices contribute to operating cost and indoor air comfort.

When the above procedures are in-co operated into an installation and high SEER equipment is part of the installation, both the installer and the customer benefits greatly.

The HVAC industry, Government regulatory agencies and regulatory bodies should provide the environment for customers to be satisfied with services that they pay for. They need to be able to compare the operation cost pre and post installation.