How Important Is The Refridgerant Charge?

More than 30% of newly constructed houses and newly installed air conditioning systems in Los Angeles have the wrong refrigerant charge. Refrigerant is the compressed gas that cools the air in your home. It is commonly referred to as freon and comes labeled as 410A and R-22.

Many home owners find it hard to believe that their air conditioner is improperly charged especially since the air conditioning system is working.

Los Angeles home owners assume their AC system is working properly if it is blowing cold air. We think it should be blowing cold air at the lowest possible cost and wthout causing excessive wear and tear on your equipment.

An overcharged system will blow cold air but use more electricity. An undercharged system will blow cold air but use more electricity. Both situations lower the life expectancy of the air conditioning system. Not to the point it breaks tomorrow. A life expectancy of a properly installed central AC system is many years. Overcharging and undercharging shrink the number years the system will operate.

Why Should You Care If Your Contractor Has Workman's Compensation Insurance?

          One of the things you like about your contractor is that he's cheaper than all the rest right?
He's giving you a good deal. Or so you thought...

          The contractor you hire to trim your trees or repair your air conditioning system is supposed to carry workman's compensation insurance for their employees. If not, they could end up costing you every penny you have. Homeowners insurance usually only covers domestic employees like maids and babysitters, it does not cover work that should be performed by a licensed contractor. The homeowner is required to check and make sure that any laborer working on their property is covered. Most homeowners do not realize that they are personally liable if an uninsured worker is injured on their property.

California law is very clear:

            It is the homeowner’s responsibility to verify that repairmen and contractors are properly licensed and insured. If a homeowner hires a contractor who does not carry the appropriate liability and Workers Compensation insurance, the homeowner is liable if an accident happens.  

 

          There is an easy way to make sure a contractor is properly licensed and insured.

The Contractors State License Board makes it easy to check your service providers.

1. Go to CSLB.ca.gov

2. Search for service providers by business name, a worker’s name, or a license number.

3. Find out whether the contractor is properly licensed and insured, and whether they pay workman’s compensation for their employees.

          Above is a screen shot of a page from the Contractors State Licensing Board that shows what a properly insured air conditioning contractor in Los Angeles should look like. As you can see they are covered for worker's compensation. Every heating and air conditioning system installation contractor should carry workers comp, but many of them do not. 

Why don’t all contractors carry Workers Compensation coverage?

            Workers compensation coverage is expensive. A contractor who cuts costs by skipping it can offer a lower price than a contractor who insures his employees properly, however, a low bid can turn into a very expensive nightmare.

          Most of the time, accidents do not happen. But when they do, homeowners are ultimately responsible for what happens on their property. Protect yourself from irresponsible contractors by checking their credentials and their insurance history at CSLB.ca.gov.

Central AC: Repair or Replace?

The heat wave that has hit Los Angeles and the San Fernando Valley this summer has had many homeowners calling AC repair companies to find out whether it still makes sense to repair their older central air conditioners or if replacement is a better option.

One 5 ton and two 3 ton American Standard 15 SEER super quiet units were installed at this 6,000 square foot home in Tarzanna.

After the unit reaches a certain age several factors can make it more sensible to replace the central AC rather than continually invest in costly repairs.

Repair or Replace Factors For Homeowners

Age of the Central AC and Heating Unit - Is your central Air conditioner older than 10 years? Depending on the brand and the quality of the installation 10 years can be the point at which equipment may start breaking down and requiring higher repair bills each season.

Higher Energy Bills in Summer - It won't come as a surprise to hear that your old Air conditioner is not much of an energy saver. By upgrading to a higher efficiency air conditioner or heat pump system you can expect to save approximately 40% in energy costs.

R22 Refrigerant is Leaking - Refrigerant is a toxic substance controlled by the EPA. It's expensive and reoccurring leaks are an indication that major repairs are needed.

Cost of Repairs - In Los Angeles Air Conditioning repairs are not cheap! If the cost of repair is more than $750 you are 1/4 of the way to a replacement AC unit. Remember you don't always have to replace the entire system. You can replace the AC only.

Frequency of Repairs - Even when AC repair costs are minimal, say $150 per repair, if you are having your central AC several times per year it may be time to consider a replacement unit.
A good central air conditioning contractor will help you decide what is best for you and for your home. It's always a good idea to get 3 different prices for replacing your central air conditioning and many San Fernando Valley air conditioning contractor will give a free estimate.

Home Maintenance Checklist

On a monthly basis:

• Clean or replace the HVAC filters [typically located at your fresh air return]. If you have an energy recovery system (air exchange system), remember that these filters also need to be cleaned or replaced.
• Inspect, clean or replace kitchen vent hood filters (non-charcoal filters).
• Flush all toilets and run water through all sinks, especially in bathrooms that are not used on a regular basis.

It's easy to find filters for your HVAC system. This is the selection at Target.

On a quarterly basis:

• Check the exterior drainage conditions to ensure that nothing is causing water to stand in puddles for more than 24 hours and that water from any source is not draining toward your foundation.
• Check your GFCIs (ground fault circuit interrupters) for proper operations by tripping the circuit interrupter buttons and then resetting them. If they will not trip and reset, contact your Customer Care Department for service or information on what to do.
• Inspect, lubricate and clean all of your exterior vents. Make sure that air flows freely and that each has an operable damper to prevent back flow of outside air and to keep small animals from entering your home.
• Lubricate all overhead garage door hinges with white lithium spray.
• Inspect and clean all weep holes for water drainage (windows).

On a seasonal basis:

• Every six months, inspect and service your HVAC system.
• Twice a year, you should inspect and repair the following caulked areas, as necessary.
• Kitchen and bath wet areas. Ensure that the caulked areas are not cracked and separating. If they are you will need to re-seal those areas.
• Bathroom/commode areas. Check the sealant where the stool meets the floor to insure the sealant is intact.
• Window and door seals.
• Around all penetrations (hose, faucets, duct work from vents, fireplace and chimney vents).
• Vinyl, aluminum or wood siding.
• Stucco or mortar cracks.
• Interior settling or shrinkage sheetrock cracks.
• If you have a basement and it has a sump pump, check to make sure it is operating properly, clean the pump screen and remove any soil buildup from the well.
• Clean and repair gutters. Make sure gutters are free of material that could prevent free flow of water. Make sure you have splash deflectors at the base of the downspout to deflect water away from the home.
• Inspect and adjust sprinkler systems. Set your timers for the proper season to ensure enough, but not too much water per station.

On an annual basis:

• Drain and refill your hot water heater(s). This may be necessary on a more frequent basis if you live in an area with extremely hard water.
• Inspect and test your hot water heater safety valve (T&P Valve typically located on the top or near the top part of the water heater).
• Inspect your garage door(s), rails and lock system; adjust and lubricate, as necessary. Consider changing your garage door opener code as a security precaution.
• Service your lawn mower and yard equipment (blowers, edgers and trimmers).
• Clean your faucet aerators and inspect your plumbing for leaks (includes all p-traps [waste line at sinks] and angle stops [shut-offs at commodes and sinks]).
• Clean and sharpen your garbage disposal by running a tray of ice cubes and depositing a cleaning (foaming) product into the disposal.
• Inspect or have tested your home fire extinguishers.
• Replace smoke alarm batteries.

Is your Old Central Air Conditioner Worth Fixing?

The heat wave that has hit Los Angeles and the San Fernando Valley this summer has had many homeowners calling AC repair companies to find out whether it still makes sense to repair their older central air conditioners or if replacement is a better option.

After the unit reaches a certain age several factors can make it more sensible to replace the central AC rather than continually invest in costly repairs.

Repair or Replace Factors For Homeowners

• Age of the Central AC and Heating Unit - Is your central Air conditioner older than 10 years? Depending on the brand and the quality of the installation 10 years can be the point at which equipment may start breaking down and requiring higher repair bills each season.
• Higher Energy Bills in Summer - It won't come as a surprise to hear that your old Air conditioner is not much of an energy saver. By upgrading to a higher efficiency air conditioner or heat pump system you can expect to save approximately 40% in energy costs.
• R22 Refrigerant is Leaking - Refrigerant is a toxic substance controlled by the EPA. It's expensive and reoccurring leaks are an indication that major repairs are needed.
• Cost of Repairs - In Los Angeles, the San Fernando valley and Beverly Hills Air Conditioning repairs are not cheap! If the cost of repair is more than $750 you are 1/4 of the way to a replacement AC unit. Remember you don't always have to replace the entire system. You can replace the AC only.
• Frequency of Repairs - Even when AC repair costs are minimal, say $150 per repair, if you are having your central AC several times per year it may be time to consider a replacement unit.

A good central air conditioning contractor will help you decide what is best for you and for your home. It's always a good idea to get 3 different prices for replacing your central air conditioning and many San Fernando Valley air conditioning contractor will give a free estimate.

Proper Sizing of Central Air Conditioning

Whether you are looking to install a new central air conditioning unit or replacing a current unit, it is important to use the correct size unit. A that is too small will run continuously without adequately cooling the house, while a unit that is too big is overly costly and, due to frequent on/off cycles, can cause humidity problems.

Proper System Sizing 

In order to scientifically calculate the right central air conditioner size, you can perform a Residential Load Calculation. The sizing chart above is useful to help you determine your approximate central air conditioner size requirements.

Another way to size replacement air conditioners is to determine the system size that is currently in place. The manufacturers do not list the air conditioner size on the unit. The system capacity will be coded into the model number of the outdoor unit. For example, model CKL24-1 is a 2 ton unit.
Why? There are 12,000 Btu's per ton. The number 24 in the model number indicates the unit is 24,000 Btu's, divided by 12,000 Btu's per ton, equals 2 tons. 24,000 Btu's/12,000 Btu's per ton = 2 tons Use the following conversion information to determine your existing system size (use the system model number NOT the serial number) 18 = 1.5 tons 24 = 2 tons 30 = 2.5 tons 36 = 3 tons 42 = 3.5 tons 48 = 4 tons 60 = 5 tons.

When sizing air conditioners, be careful not to make the mistake of getting one that is too large. If the system you install is too large for the space, it will short cycle. In other words, the compressor will not run long enough to dehumidify the space and will limit your comfort. In addition, it will cycle on and off more frequently, increasing operating costs and reducing the system life.

Insulation Variables Variables such as your insulation, type and number of windows, number of stories, construction type, etc. will greatly affect the required Btu's per square for both heating and cooling. A general rule of thumb is that if your home is well insulated with newer style windows, you can select the smaller size system that falls within your total square footage.

If your home is two story it will place less of a load on the system in the downstairs area as the second floor acts as additional insulation. If your home is not well insulated, has older style windows, and/or a larger than average number of windows, you will want to select the larger system which falls within your square footage range. The less insulated and more windows within the environment, the more likely you will experience greater air and heat loss.

Proper air conditioner sizing is critical to optimize performance.

The HVAC Factor: Energy Recovery Ventilation

By Stephen J. Pargeter
Originally published in the August 2012 issue of Today’s Facility Manager

Studies have proven that outdoor air ventilation creates a healthful work environment. However, as these intake rates increase, so does the size, cost, and operating expense of the heating, ventilation, and air conditioning (HVAC) system. Facility managers (fms) are therefore caught between two powerful forces—the need to lower energy costs and the need to meet or exceed outdoor air ventilation regulations for occupant health and comfort.

During the ventilation process, large amounts of energy are wasted as HVAC systems replace indoor air with fresh outdoor air multiple times per day. The heating or cooling energy is continually lost in the exhaust air stream while new energy must be expended to condition entering outdoor air. Those who fail to capture wasted energy will continue to incur high energy costs.

To address this challenge, one option for fms is a site recovered energy technology such as energy recovery ventilation (ERV). Site recovered energy is any energy recovered on-site and reused to reduce the demand for more energy. Designed to operate with new or existing HVAC units, the ERV technology provides a means to cut energy costs without compromising outdoor air ventilation requirements.

While there are a number of air-to-air heat exchangers used in ERV, the most commonly used type in commercial and institutional buildings is a rotary heat exchanger (also known as an energy recovery wheel or enthalpy wheel). This wheel resolves the conflict between indoor air quality (IAQ) and energy conservation by recovering site energy normally wasted in exhaust air. It transfers energy by rotating between incoming (outdoor) and exhaust air streams to transfer heat and moisture from one air stream to the other, recycling up to 80% of this energy by preconditioning outdoor air for significantly reduced HVAC load and operating cost.

Rotary heat exchanger

Total energy saved depends on the wheel’s effectiveness and the difference in temperature and humidity between the two air streams. A bigger differential means larger energy savings.
For new and replacement projects, energy recovery costs are typically offset by lower first costs for an HVAC system. And significant reductions in fuel consumption provide healthy returns for the life of the HVAC system—instant to two-year paybacks in most North American climate zones. An energy recovery wheel may also be added to an existing HVAC system to improve efficiency.
HVAC systems with ERV improve control over humidity to minimize mold and mildew and reduce the risk of IAQ complaints and sick building syndrome, especially in humid climates. Meanwhile, many gas and electric utilities offer rebates for energy recovery to reduce peak demand and encourage energy conservation.

Organizations Using ERV
To meet new building codes, Dillard’s, a large apparel and home furnishings retailer, sought to increase outdoor air ventilation rates by a factor of three at its store in Palm Beach, FL. The two story building required approximately 50,000 cfm (cubic feet per minute) of outdoor air. Rather than add capacity to meet the increased load, management at Dillard’s installed rooftop units with integrated energy recovery wheels. By reducing the load by 160 tons, the retailer was able to choose units with that much less capacity. And by reducing peak demand by 215 kilowatts (kW), the company qualified for utility rebates that effectively paid for the wheels. The use of ERV is now standard for all Dillard’s stores.

Another example of this technology involves a major renovation at the Providence Career and Technical Academy (PCTA) in Providence, RI. The engineering team there chose to install a dual temperature, two pipe HVAC system with energy recovery wheels to maintain control of humidity during the shoulder season. The improved efficiency has yielded an estimated savings of $28,000 per year.

Another ERV adopter is the Eddy Village Green in Cohoes, NY, a nursing home complex of 16 housing units, each with 12 bedrooms. Each of those units has a 13 ton HVAC system with an integrated energy recovery wheel that supplies 3,500 cfm of outside air. In addition to an estimated upfront combined savings of $20,208 from installing smaller packaged units, the facility hopes to recover an estimated ongoing savings of $23,168 based on local utility rates.

Evaluating ERV Systems
Fms who are interested in finding out about the potential of ERV can begin by looking for the following characteristics in a system. These include products that feature:

• rating and certification by the Air-Conditioning, Heating and Refrigeration Institute (AHRI);
• high humidity (not just heat) transfer capability;
• easy accessibility and cleaning; and
• performance modeling software.

Fms should also look for established providers of these systems. Most mainstream HVAC equipment manufacturers offer energy recovery wheel options for new or existing applications.
The energy demand posed by outdoor air ventilation requirements is a pressing issue among fms eager to save money while still providing clean, healthy buildings. Energy recovery wheels offer a way to cut energy costs and supply ample outdoor air ventilation while also garnering a high return on investment.

Pargeter is vice president, Product Engineering, at Airxchange, a Rockland, MA manufacturer of energy recovery wheels. He holds a BSc (Honors) degree in Production Engineering and Production Management and has served on the board of directors of the Air-Conditioning, Heating and Refrigeration Institute (AHRI).