Manual J. – What is it and how is it Used to Size Your South Georgia AC System?

Published on: July 20, 2012

Even though there are many free or inexpensive ideas and ways Albany GA residents can upgrade their home or business to be more energy efficient, sometimes purchasing a better product in the short-term in order to save more money in the long-term makes better sense. Air conditioner maintenance and installation is a perfect example of that strategy. Think of it as an investment in energy efficiency that allows you to save hundreds, maybe thousands of dollars in future utility costs.


Practical Air Conditioner Service Upgrade

The size of your home or business and how much cooling it needs plays a crucial role when choosing a new air conditioner. The system must be properly sized in order to operate at its most optimal and economic potential. The air conditioning system must be able to handle the “load” that is required to keep your indoor environment consistently comfortable.

However, contrary to popular belief, bigger is not always better. You wouldn’t purchase an eighteen-wheeler just to make periodic errands around town because the vehicle would end up costing you more to operate than your needs required. The same is true for a heating and cooling system. If the system is larger and more expensive than necessary, then you’re paying to operate components you don’t need.

Over-sized air conditioning systems are also incapable of dehumidifying the indoor air. For example, most air conditioning systems must run for at least ten minutes to dry the coils as they become cool enough to form condensation. If the cooling system is too big, then the thermostat will likely shut down before the blowers have a chance to remove the moisture. This creates an atmosphere and breeding ground for toxic mold and mildew.


The Benefits of Manual J – “Residential Load Calculation”

In order for an AC maintenance contractor to analyze and determine the cooling load of your home or business, or find the right size system that fits your needs, they will perform a series of calculations based on Manual J guidelines. This industry-standard manual, which was published by the Air Conditioning Contractors of America, incorporates all standards, technical details and the implementation of HVAC system calculations.

Developed by a group of HVAC engineers, the guidelines have been repeatedly tested and validated via actual real-world applications. There are three basic factors that are used to accurately calculate the size system necessary for each indoor space, which include:

• Heating Load – used to calculate peak heating needs during the coldest days of the year
• Sensible Cooling Load – used to calculate the amount of heat the system needs to remove on the hottest day of the year
• Latent Cooling Load – used to calculate the amount of moisture the system needs to remove from the indoor environment during the most humid conditions


Room-by-Room Loads

The AC maintenance expert will also calculate the individual load requirements of each room of your indoor environment. This is required in order to determine individual thermostats that are set to monitor and control different areas of the building, known as zoning. It also helps to determine how much air circulation is needed in each room, which is highly useful in constructing efficient ductwork systems throughout the building. An AC maintenance technician will use these calculations to ensure that you aren’t getting too much or too little air than is needed in each room on any given day of the year.


Other Important Information

An AC maintenance expert also uses other factors when determining the proper system size for your indoor environment, which include:

• Size, shape and orientation of the indoor structure
• Number of windows, size and locations
• Type of insulation
• The number of occupants and their needs
• The types and number of indoor appliances that give off extra heat
• Air infiltration and circulation rates


Obligation of an Air Conditioner Service Professional

These calculations are crucial for any conscientious consumer who wants the most efficient and cost saving heating and cooling system for their indoor needs. South, GA residents should insist that an air conditioner service contractor use and apply the correct sizing methodologies before signing any sort of contract, and Manual J should be included. This type of AC maintenance estimation is usually offered at little to no charge, depending on the contractor.


Of course, other factors need to be considered when determining the right size system, such as future construction upgrades or unexpected changes in the living conditions. System size estimations based on the load data shouldn’t exceed fifteen percent than what is needed. A reputable air conditioner service professional will utilize this methodology and use this array of latent heating/cooling load information to determine the precise equipment suitable for each indoor space. As a result, this will greatly boost your system’s efficiency, reduce your energy costs, and enhance your comfort and standard of living.