i Heat Cool  (click iHeatCool.com)  See our link to US Search for employment background checks.

Employers check potential and current workers for several reasons. The things an employer wants to know about you can vary with the kinds of jobs you might seek. Here are a few of the reasons for employment screening.

•Negligent hiring lawsuits are on the rise. If an employee’s actions hurt someone, the employer may be liable. The threat of liability gives employers reason to be cautious in checking an applicant’s past. A bad decision can wreak havoc on a company’s budget and reputation as well as ruin the career of the hiring official. Employers no longer feel secure in relying on their instinct as a basis to hire.

•Current events have caused an increase in employment screening.

•Child abuse and child abductions in the news in recent years have resulted in new laws in almost every state that require criminal background checks for anyone who works with children. The move to protect children through criminal background checks now includes volunteers who serve as coaches for youth sports activities and scout troop leaders.

•Terrorist acts of September 11, 2001, have resulted in heightened security and identity-verification strategies by employers. Potential job candidates and long-time employees alike are being examined with a new eye following September 11, 2001.

•Corporate executives, officers, and directors now face a degree of scrutiny in both professional and private life unknown before the Enron debacle and other corporate scandals of 2002.

•False or inflated information supplied by job applicants is frequently in the news. Numerous studies and news articles, citing varying results, have been published on the topic of resume fraud. While study and survey results may vary, it is clear that human resources professionals are alert to the potential for embellished or outright falsehoods. Such reports make employers wary of accepting anyone’s word at face value.

For more on resume fraud, see Sam H. and Della L. Dekay, Lying On The Employment Resume: Is it Legal?, presented at the 2008 Association for Business Communication, www.businesscommunication.org, Convention.

www.businesscommunication.org/conventionsNew/proceedingsNew/2008New/13ABC2008.pdf

•Federal and state laws require that background checks be conducted for certain jobs. For example, most states require criminal background checks for anyone who works with children, the elderly, or disabled. The federal National Child Protection Act authorizes state officials to access the FBI’s National Crime Information Center (NCIC) database for some positions. Many state and federal government jobs require a background check, and depending on the kind of job, may require an extensive investigation for a security clearance.

•The "information age" itself may be a reason for the increase in employment screening — the availability of computer databases containing millions of records of personal data. As the cost of searching these sources drops, employers are finding it more feasible to conduct background checks.

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Very professional video on Heat Cool Tune-Up

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You can use the procedure in this video to measure the real time capacity of the heat cool unit.  It’s not unusual to find a 3 ton unit only producing 1 or 2 tons of cooling.

Recommission the system to restore original capacity.

It’s never too late to reduce energy consumption or prevent additional breakdowns for your Heat Cool System.  There are several ways to check for and resolve problems associated with your central air conditioning.  Common problems include frozen coils, condensate leaks, bad motors, ants in contactors and more serious problems including the compressor failing.

The first thing you should do if your air conditioner is not functioning properly is to check the fuse box or circuit breaker that services the unit. The fuse may need to be replaced or the circuit breaker reset.  Also, if the air conditioner turns on and off frequently, the unit may be low on refrigerant or the compressor and fan controls may be worn out.

If your unit is turning on, but the air isn’t cooling efficiently, your refrigerant may be low. You may also need to clean off the evaporator or condenser coils by brushing them off or vacuuming them. In addition, the filter may need to be replaced. Clogged, dirty filters block normal airflow and reduce a system’s efficiency considerably.

Water leaks are usually associated with low refrigerant or a clogged drain pipe. Clogs can be fixed by clearing out the clogged pipe within the evaporator coil pan.

Looking For More Information on Heating and Cooling?
If you’re familiar with the safety practices required for inspecting and diagnosing appliance problems, check our FAQ and Knowledge Base. 

Heating and cooling your house is an important aspect of your home life. You’ll want to make sure you are choosing the right contractor for your home, business and your budget.

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See the following video, for a Heat and Cool Air Conditioner Refrigerant update.

“Freon” is a trade name for a family of refrigerants manufactured by DuPont and other companies. These refrigerants were commonly used due to their superior stability and safe properties. Unfortunately, evidence has accumulated that these chlorine-bearing refrigerants reach the upper atmosphere when they escape. Once the refrigerant reaches the stratosphere, UV radiation from the Sun cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine atoms catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth’s surface from strong UV radiation. Each chlorine radical remains active as a catalyst unless it binds with another chlorine radical, forming a stable molecule and breaking the chain reaction. CFC refrigerant is common, but decreasing usage includes R-11 and R-12. In light of these environmental concerns, beginning on November 14, 1994, the Environmental Protection Agency has restricted the sale, possession and use of refrigerant to only licensed technicians, per Rules 608 and 609 of the EPA rules and regulations; failure to comply may result in criminal and civil sanctions.

Newer and more environmentally-safe refrigerants such as HCFCs (R-22, used in most homes today) and HFCs (R-134a, used in most cars) have replaced most CFC use. HCFCs in turn are being phased out under the Montreal Protocol and replaced by hydrofluorocarbons (HFCs) such as R-410A, which lack chlorine.

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Every homeowner and commercial building owner should a copy of the calculations that determine the size of their air conditioner.  This engineering information is commonly called heat gain, heat loss calculations, load calculations or energy audit.  Air conditioning contractors or service companies will usually provide this information at no charge.  This knowledge is essential when selecting insulation, windows, roof color, window coverings, landscape features and many more decisions.

AC units were historically sized based on the square footage of the structure.  An example was 500 square feet per ton for cooling.

The price of energy has gone up, builders have learned to build a tight house and I’ve seen a 3000 square foot home in Texas that only needed one ton of cooling.  3000 square feet per ton.

What size air conditioner do you need?  You need somewhere between one ton for each 300 to 3000 square feet.  Skipping the engineering step when sizing a unit is air conditioning malpractice

Heat Gain Calculations

Building Envelope.  The proper method to determine the size unit needed is to measure or calculate how much heat gets into the structure or building envelope.  Heat gets in through the ceiling, walls, windows doors and sometimes the floor.  If you measure or calculate the heat gain through each of these building envelope components, you can determine how many BTU’s per hour you need to offset the heat gain.  If the heat gain characteristics are different, these calculations can be done for each room or zone.

If you had a 3000 square foot ceiling with R-38 insulation under a ventilated attic in Dallas Texas, and you want the inside of the house 30 degrees cooler than the outside of the house on a 100 degree day, you need 3000 X 1.8 Btuh per square foot of ceiling.  The heat gain is 5,400 Btuh.  (12000 Btuh per ton) about a half ton.  If you had R-19 ceiling insulation you need 3000 x 3.4 or 10,200 Btuh.  You can determine this value for all building envelope components.  It’s good information to know if you’re deciding to add insulation and downsize your AC unit.

Internal Heat Gain.  In addition to heat gain through the structure heat is generated inside the building envelope from lights, appliances, people, etc.  (10) 100 watt light bulbs produce 1000 watts x 3.413 Btuh for 3413 Btuh.  If you replace the 100 watt lamps with 19 watt CFL’s, this is good data.  You can reduce the size of the AC Unit more.

Infiltration and Ventilation.  Air gets into your structure through leaky windows, doors, dryer exhausts, kitchen exhaust etc.  The air you have already cooled gets out and is replaced with hot humid air from outside.  The humidity is called latent heat.  The AC must use additional capacity to eliminate this humidity.  The capacity that is used to remove the humidity is not available to reduce the temperature of the air.  This humidity or latent heat must be measured or calculated and Btu’s from the AC Unit must be available to remove it. 

A blower door test can be run in an existing building to measure the amount of outside air entering the house.  The decision can then be made to put in a bigger AC to take care of it, or to seal up the source of the leaks.  In a normal house 30% of the AC Units capacity is used for dehumidification or removing latent heat.  You need to get this calculation right so you don’t live in a cool humid cave.

One last calculation is to measure or calculate the amount of leakage and heat gain into your ductwork, if your ductwork is in an unconditioned attic.  This is normally 15% of the unit size or more.  It can be a lot more.  You might want that ductwork under the floor, in conditioned drywall fur-downs or you might want to insulate your roof and not your ceiling.

Invest some time and learn to calculate your heat gain.  You can ask your HVAC contractor to do it. 

Michael Glover

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m@Michael-Glover.com

Cleaning the Residential Air Conditioning Condenser

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The condensing unit is located outside where it can accumulate dirt and debris from trees, and airborne dust. The condenser has a fan that moves air across the condenser coil. You must clean the coil on the intake side, so, before you turn off the power to the air conditioner, check to see which direction the air moves across the coils.

Step 1:  Cut down any grass, weeds, or vines that have grown around condensing unit.  Keep an area clear of at least three feet on all sides of the intake.

Step 2:  Turn off the power to the unit. Code requires a disconnect be within site on a wall.

Step 3:  Check the power terminals with a voltmeter to make sure power has been disconnected.

Step 4:  Clean the condenser coil with commercial coil cleaner, available at refrigeration parts supply. Coil cleaner with a mild citric acid is the strongest chemical you should use. Instructions for use are included. Be careful not to force dirt into the fins where it can become lodged and block air flow. Flush coil clean being carefully not to bend or damage the delicate aluminum fins. Rinse the entire cleaner from the coils.

Step 5: Clean fins with soft brush to remove accumulated dirt. You may have to remove a protective grille to reach them. Clean fins carefully with garden hose, being careful not to bend the delicate fins with excess pressure. Clean fins very carefully: They’re made of light-gauge aluminum and are easily damaged. If fins are bent, straighten them with a fin comb, sold at most refrigeration parts stores. A fin comb is designed to slide into spaces between fins. Count the fins per inch on your coil to get the right size.  Use it carefully to avoid damaging fins.

Step 6: Check concrete pad on which condenser rests to make sure it’s level. Set carpenters’ level front to back and side to side on top of unit. If pad has settled, lift pad with pry bar or piece of 2 x 4, then force gravel or rocks under concrete to level it.

During the fall and winter, outside condenser AC units should be protected from the elements to prevent leaf blockage and ice damage. Cover the condenser unit with a commercial condenser cover made to fit the shape of the unit or use heavy plastic sheeting secured with sturdy cord.  If your AC is also a heat pump, do not cover.

http://iheatcool.com/diognostics/

same idea can be applied to the cooling system, close to the edge of the ideal free cooling times for

your economizer.