Tag Archives: HVAC system

3 Heating and Cooling Ratings You Should Know

heating and cooling ratings

If you are interested in upgrading your heating or cooling system, you’re going to come across some important acronyms as you compare systems. Understanding these HVAC system ratings will help you to narrow down your options to the best pick for your Loxley, Alabama, home.

Seasonal Energy Efficiency Ratio – SEER

If you are considering a new cooling system, the SEER will give you some important information about the unit’s efficiency. The SEER is calculated by dividing the cooling output over the course of a season by the seasonal electrical energy input. The higher the SEER rating, the more efficient your system. If you have an older system, it may have a SEER of six or lower. However, most systems manufactured today must have a minimum SEER of 14, and some rank in the 20s.

Annual Fuel Utilization Efficiency – AFUE

Central furnaces and boilers are rated using the AFUE. This number represents the ratio of annual heat output to the total fossil fuel energy consumption over the same period. If a furnace has an AFUE of 90 percent, this indicates that 90 percent of the energy from the fuel is converted to heat in the home, while the remaining 10 percent escapes. A mid-range system generally has an AFUE around 80 to 83 percent. High-efficiency systems have an AFUE of 90 or higher.

Minimum Efficiency Reporting Value – MERV

MERV ratings are used for HVAC filters. The lower the number, the less filtration you’re provided. A MERV of four or lower will only filter out particles of 10 pm or more, like dust mites. A MERV between five and eight is most common for residential buildings, filtering out particles as small as 3 microns, like mold spores. Superior residential systems may have a MERV up to 12, which will stop particles 1 microns in size or larger, like lead dust, auto emissions, and Legionella.

If you are considering a new heating or cooling system installation in your home, contact Keith Air Conditioning, Inc. at 251-476-3610 to learn more about your options.

HVAC system | Keith Air Conditioning

Choosing the Right HVAC System for an Energy-Efficient Home


energy efficientHVAC systems don’t last forever, and when it’s time to install a new one, the decision can be difficult. With the introduction of new technology, there are many options for a new purchase or even technologies that can enhance the efficiency of your current system. Since your HVAC system performs a vital function in your Mobile, Alabama, home, and is a major investment. It is important to make an informed decision when making any type of upgrade. The following are a few factors to keep in mind when choosing a new HVAC system for an energy-efficient home.


Not all HVAC systems heat or cool a home the same way. If you live in a smaller home, you don’t need an HVAC system with a high heating or cooling capacity because you will end up wasting energy. On the other hand, if you live in a large home or are installing a system into a large business, a small HVAC system may not have the capacity to keep the building at a comfortable temperature. Before deciding on a system, research the heating and cooling capacities. For the most effective solution, consult your HVAC technician.


When installing a new HVAC system, consider the current technology that can turn your system into a highly-efficient machine. Smart thermostats keep the temperature under precise control, allowing you to save as much as possible on your utility bill. Whole-home air purifiers provide additional filtration power to significantly improve your indoor air quality. These and other innovations will save you money while keeping you comfortable.

Advanced Options

There are many options for managing the temperature and indoor air quality in your home including ultra-efficient heat pumps and radiant heating. Depending on the size and location of your home, these options could save you more money than a standard HVAC system would.

If you would like to learn more about HVAC systems or would like to invest in a newer, more efficient model, give Keith Air Conditioning, Inc. a call today at 251-476-3610.


good ductwork design | Keith Air Conditioning

Follow These Principles for Good Ductwork Design

ductwork design

Central or forced air HVAC systems rely on a system of ducts to get conditioned air to every vented area of your home. How well your central heating and cooling works depends a lot on good ductwork design.

Ductwork carries conditioned air from the utility area where your furnace or air conditioner is installed into the living areas of your home. When it is working as it should, each room in your house gets an appropriate volume of air delivery, and the air reaches the vents as warm or as cool as it’s meant to be. When ductwork is improperly designed, however, leaks, heat loss or heat gain, and excessive or insufficient airflow can plague your home. In fact, these flaws can drop an HVAC installation’s efficiency down to 60 percent of its ideal operating conditions. That’s not just bad for the energy bills, it’s bad for home comfort.

Principles of Good Ductwork Design

  • In new homes, ductwork should be designed at the same time the house plans are being drafted. The Air Conditioning Contractors of America (ACCA) offers updated guidelines on how best to approach residential duct system design.
  • Good ductwork design takes into account the heating and cooling loads of each room, not just the entire house. Inner rooms may require less conditioning than rooms that are more affected by outdoor temperatures through conduction and radiation, for example, through walls, ceilings, windows or doors. And smaller rooms, such as bathrooms, require less airflow than larger living spaces.
  • When the heating and cooling loads are calculated, the specific models of furnace and air conditioner should be determined. This is because the rate of air supply provided by the blower fan can impact the size of duct necessary.
  • The location of the central HVAC system should be considered as part of good ductwork design. Symmetrical or nearly-symmetrical ductwork often performs best when it comes to delivering the correct amount of air to every room, which means that tucking the HVAC appliances into an out-of-the-way location can have undesirable consequences for airflow.
  • The duct layout should also take the location of other appliances into account. For example, a duct should not be installed next to a water heater, as the heater may transfer heat into the duct during the cooling season, reducing the efficiency of the home’s air conditioner.
  • When the equipment is selected, contractors should draw up a sketch of your home’s entire air distribution systems in order to calculate the duct size requirements. This step can also help the contractors decide what method of distribution is best: a trunk-and-branch system, where one main trunk duct supplies a number of smaller branch ducts which carry air to each room, for example. Good ductwork design will be fine-tuned to the architecture of the building, as well as the climate.
  • Ideally, ductwork should be kept in conditioned or insulated areas of the home. Insulating the ducts helps to prevent heat loss and heat gain. Keeping the ductwork securely within the home’s thermal envelope also helps to retain energy.
  • When the size and layout of ducts has been selected and the ducts are being installed, the contractor should pay special attention to sealing duct connections with mastic to ensure that no air leaks are present in the system.

Good ductwork design governs year-round home comfort when it comes to heating and cooling your home. In addition, improved airflow throughout your home optimizes the performance of your HVAC system.

To learn more about ductwork design, how to get the most out of your ductwork, and proper ductwork maintenance, contact the experts at Keith Air Conditioning, Inc. at 251-476-3610. Our technicians can provide a variety of energy-efficient solutions and systems to improve indoor air quality, energy savings, and comfort in your Mobile-area home or office.