How To Choose An Indoor Comfort System

Selecting a heating and cooling system and indoor air quality equipment for your home is important to your family’s health, indoor comfort and long-term energy savings. Whether you are adding a system to a new home, replacing an older system or supplementing your current system, the following information may provide you with the tools you need to make the right decisions for your needs.

While the initial cost of new equipment may seem high, energy savings that will be realized through increased efficiency often justifies replacement. This improved efficiency is not only good for you, but also helps reduce your home’s electrical demand, which is ultimately good for the environment.

Many homeowners during some point of their ownership may have to replace their central air-conditioning and heating systems. The average life span of central air-conditioning and heating systems is 12 to 15 years, if the units were properly installed and maintained. Heat pumps have about the same life-span (about 12 years), again when recommended maintenance is followed. Newer units manufactured in recent years are expected to last even longer.

When the system starts giving you more problems than seem cost-effective to fix, it may be time to consider purchasing a new system.

It is important to know that split air-conditioning and heat-pump systems consist of two parts: an indoor (coil) unit and an outdoor (condensing) unit. These two parts are specifically designed to work together as a coordinated “team” to provide top performance and maximum efficiency and comfort.

In the past, homeowners could sometimes replace part of their system, such as the outdoor condensing unit, to extend its useful life. However, air-conditioning and heat-pump systems manufactured today, by law, must have at least a minimum Seasonal Energy Efficiency Ratio (SEER). For these new, high-efficiency systems to work properly and to extend their life, the outdoor unit and indoor unit must be perfectly matched. So if you install a new high efficiency outdoor unit, but don’t install a new, equally efficient and properly matched indoor unit, the results could be uncomfortable, frustrating, and expensive. Because newer equipment usually is more energy efficient than older central air-conditioning or heat-pump systems, you will likely see reduced energy usage of up to 30%.

Homeowners should ask their air-conditioning company to size the equipment to meet the specific needs of their homes. If a system is undersized, it will continuously run without properly cooling your home. If oversized, the system will cycle on and off too frequently, greatly reducing its ability to control humidity. It also will be less efficient.

To properly size a system for a home, trained professionals will use an equation that factors the home’s age, the number and quality of its windows, how well it is insulated, how many levels the house has, its total square footage, and local energy rates. Homeowners should ask their contractor company to perform a Manual J analysis, the industry’s term for the standardized equation used to properly size an air-conditioning system. The results will specify the cooling capacity of the system in either Btu/h (British thermal units of heat removed per hour) or refrigeration tons (one ton being equal to 12,000 Btu/h).

When installing a new air conditioning system, you will need to consider your home's electrical system. It is not uncommon for old houses to have only 110-volt, 60-amp service for the entire home—barely enough power to handle the home's existing lights and appliances. Central air conditioners require a dedicated 230-volt circuit and may require 20 to 50 amps of power, making an electrical service upgrade necessary.

Air conditioning manufacturers are required by law to evaluate and rate their equipment according to its energy efficiency. This rating for central air conditioning is known in the industry as a Seasonal Energy Efficiency Rating (SEER) or Heating Seasonal Performance Factor (HSPF) for heat pump systems. The higher the SEER/HSPF, the more efficient the equipment. Generally, the higher the SEER/HSPF of a unit, the higher the cost, but the difference often can be recouped through reduced home energy usage.

Many manufacturers voluntarily submit their products for testing by the Air Conditioning, Heating and Refrigeration Institute (AHRI) to assure consumers their energy efficiency claims have been verified by an independent, third party laboratory. However, AHRI does not certify individual units, but matched air conditioning and heat pump systems, which work together as a coordinated team to achieve the given SEER/HSPF rating. Because the AHRI Certified seal is usually visible on the outside unit, it is important for consumers to double check their system is properly matched by asking their contracting company to verify this information.

You can verify that the system your contracting company is proposing is a matched system by asking them to provide you with an AHRI Certificate of Product Rating or an AHRI Certified Reference Number. For higher efficiency systems (and during available rebate programs), the certificate can be used to obtain a federal tax credit or a utility rebate.

If you do not have an AHRI Certified Reference Number, to locate your air conditioning equipment in the AHRI directory, you will need the manufacturer’s name, model name, and model number, for both the indoor and outdoor units. This information should be on the equipment’s warranty, your sales invoice and on the units themselves.

Air conditioning and heat pump manufacturers are constantly engineering innovative technologies to improve the efficiency of their equipment. Two of those technologies that help keep energy usage down are the two-stage compressors and variable-speed motors.

Two stage compressor
Two stage cooling means the air conditioner or heat pump has a compressor with two levels of operation: high for hot summer days and low for milder days. Since the low setting is adequate to meet household-cooling demands 80 percent of the time, a two-stage unit runs for longer periods and produces more even temperatures.

Longer cooling cycles also translate to quieter, more efficient operation and enhanced humidity control. Compared to a single-stage unit, a two-stage air conditioner or heat pump can remove twice as much moisture from the air. This is important because when moisture levels are high, there's a higher potential for mold and other pollutant problems.

Variable speed motors
The indoor air handler (fan and motor) provides the energy to move air through the ductwork of a central air conditioning or heat pump system to the rooms of your house. In most standard central cooling and heating systems, the fan and motor runs at one speed, which means the system is either on or off. A variable speed motor (VSM) uses control technology, meaning the VSM automatically changes speed based on your home’s heating and cooling requirements. It slowly increases up to maximum speed instead of coming on at full capacity all at once. This eliminates the sudden blast of air you feel with a one-speed system and results in the system running at a lower speed most of the time. This eliminates noisy start up, while reducing wear and tear on the fan and motor, resulting in a substantial reduction in operating costs due to major energy efficiency improvements.

Most heating and cooling systems manufactured today are quieter than those produced in past years. But there are still significant differences in sound ratings among these products.

Consumers can look for sound-dampening features such as insulated compressor compartments, discharge mufflers and innovative fan designs that work to soften the sound of a hard-working, high-efficiency compressor. Top-panel orifices, compressor wrappers and indoor blowers are all designed to further promote smooth, quiet airflow.

The amount of sound generated by a heating or cooling system can have a significant impact on comfort. Inside the home, a low sound level means no sudden blast of air at startup and smooth, vibration-free operation. Outside the home, low sound levels help you keep the peace with your neighbors.

Most heating and cooling systems manufactured today are quieter than those produced in past years. Advances have been made in reduced sound level control similarity to both air conditioning units and heat pump units. In summary, there is no distinctive difference in sound levels between air conditioner units and heat pump units.

The heating and cooling systems are sized according to their tonnage. One (1) ton equals 12,000 BTU/H. Residential systems can range from 2 to 5 tons.

Contrary to popular belief, there is no rule of thumb for sizing a system to a home. Depending upon the construction of your home, one (1) ton of air conditioning can cool anywhere from 300 to 800 square feet of home. The only way to ensure the size of the system you purchase will be large enough to cool your home, but not any larger than you need, is to have your home's individual heating and cooling needs evaluated by a licensed professional.

The SEER (Seasonal Energy Efficiency Ratio) is the amount of cooling your system will deliver per dollar spent on electricity. For example, a 3-ton unit may have a SEER efficiency rating of 13 (the lowest efficiency) to units that are rated at 20 and higher. The higher the SEER the more efficient the system will be and the lower the operating costs will be.

No. A system that is too big for your home will deliver less comfort and will cost more to operate. An air conditioner operates at its poorest efficiency when first turning on. A system with too much capacity will run in numerous short cycles, turning on and off repeatedly, therefore causing it to be less efficient. Also keep in mind that an air conditioner not only cools, but also removes indoor humidity when it's running, so a system with shorter run cycles doesn't remove humidity from the air very well. Cool, but clammy indoor air will be the result.

Before purchasing a replacement system you should always make sure your system is sized properly. Our representative will provide a heat load calculation to determine the proper size and make the appropriate recommendation. Remember, bigger is not always better.

Your best source of a good company is one that has done good work for someone you know. So ask friends & neighbors what firm they use. If they had good results with this dealer, you will have a much better chance yourself. There are way too many careless dealers and good dealers with lousy help - you have to be careful. There are many shortcuts that can be taken with the installation of new equipment that homeowners don't understand. There are issues like sizing, brand efficiency and how it is to be installed, that play an important part to the operation and comfort the system produces.

That is confusing. Most brands are similar but some are decidedly high end and some are low end. You can't always tell by the price quoted. Best bet is ask the dealer why they handle the brands they do, how long they've had them and who wholesales for them locally. It helps to work with a dealer that only handles one or two brands. Technicians and installers will be able to offer better service quality if they know the product well. Dealers that have multiple brands, or change brands often, frequently cause confusion for the technicians & installers and often parts availability is an issue. Finally, please note that the quality of the installation is more important than the brand of the product for product performance, efficiency and longevity.

A lot of dealers guess. That doesn't do you any good. Most existing equipment is too large. In the "old" days, the thought was bigger is better. But big furnaces cycling constantly are not efficient nor do they deliver even air flow and comfort. Big air conditioners cycling constantly aren't efficient, they don't remove moisture well nor do they cool evenly. The only way to know what size equipment is necessary is to survey the house. Not just square feet of floor but the energy efficiency of walls, windows, doors - anything that affects heat entering & leaving your house. Don't let someone guess at your indoor air comfort for the next 20 some years.

It depends upon local fuel rates and how long you are going to be in the house. The extra cost for a high efficient air conditioner or 95% efficient furnace is generally worth it since they will pay you back in energy savings. In extreme climates or places with high fuel rates, the payback will be very quick. In some areas, utilities offer rebates if you buy a higher efficiency system which really helps reduce your ownership costs. This is something you need to talk over with your dealer and your utility company can help you decide as well.

The cooling coil that sits above, in or below your furnace is a matched part of your air conditioning system. If you are replacing your cooling system, make sure any bid includes a new, matched cooling coil. Too many dealers are happy just to sell you the machine outside. That's doing 1/2 the job and is a mistake. Reusing an old coil reduces capacity, reduces humidity removal, reduces system life and costs more to run. Resist the temptation to save a buck. Get the old coil out of there. This eliminates everything old that can cause you grief in the future.

When discussing a new furnace with a dealer, if you have a chimney in your house that the furnace uses, there are issues to consider. If you are choosing an 80% efficient furnace, chances are a metal liner needs to be installed in the chimney to protect against condensation damage. The newer furnace has much cooler & moister exhaust than the old inefficient unit you are replacing. An un-lined chimney may cause many problems. There are safety and building codes that indicate when to use a liner. Too many dealers skip the liner and many homeowners are finding out the costly mistake that was. If you are putting in a 90% efficient or higher furnace which doesn't use the chimney for exhaust, a metal liner may still be necessary to protect the chimney for your gas water heater usage.

Many larger contracting companies employ salespeople that are trained to sell, not trained to educate and give the customer informed choices. Some of these salespeople know how to make a sale through high pressure to an undecided prospect and are not helping the homeowner choose the right system for their home. So make sure the representative offers choices and ask them to explain the advantages and disadvantages to you between the different choices. Also, make sure you get a sense of trust and integrity with any sales representative that you speak with.