What to Know About Air Conditioning
Central Air Conditioning
Central air conditioning is found in nearly nine out of ten new homes and an increasing number of people are replacing their old evaporative coolers to central air as well. Today’s modern air conditioning systems are quieter, cleaner, easier to maintain and have much lower operating costs than those found just 10 years ago. In looking at what’s new, two factors matter most when purchasing an air conditioner – S.E.E.R. rating and cooling capacity.
S.E.E.R. stands for Seasonal Energy Efficiency Rating. The higher the S.E.E.R. rating, the lower your operating costs. Each SEER point higher will equate to approximately 10% lower operating cost that the prior SEER number. i.e. If a 13 SEER air conditioner costs $50 per month to operate, a 14 SEER air conditioner would cost approximately 10% lower than the 13 SEER, therefore, estimated operating cost would be $45 per month. Remember this is just an example. Your operating costs could be higher or lower depending on what size air conditioner you need and what temperature you like to set your thermostat at. The S.E.E.R. rating is a formula derived from the cooling capacity, amperage use and voltage supplied to the air conditioner. You’ll soon become familiar with ratings with numbers of 13 through 21. The government has set the lowest allowed efficiency limit on air conditioners to 13 S.E.E.R. Many of the older air conditioners that had much higher operating costs may have had S.E.E.R. ratings of 8 or even as low as 6 S.E.E.R.
Even though the higher S.E.E.R. air conditioners save on operating costs, they also cost more to purchase. Ask one of our sales representatives at Manwill Plumbing and Heating to calculate the payback of purchasing a high-efficient air conditioner. You may be surprised at how low your monthly operating costs actually can be.
Cooling capacities are rated in tons of cooling. Nope, the air conditioner doesn’t weigh that much. One ton of cooling is equivalent to removing 12,000 BTU’s of heat from your house in one hour. It may sound confusing but this is why sales representatives from Manwill Plumbing and Heating Inc. come to your house and make an “on site” inspection. To ensure the proper size we take into consideration the direction your house faces, insulation values in the walls and attic, type of windows, color of your house, duct size and furnace blower size. All of these factors help determine what size air conditioner you really need. You’ll find ton capacities from 1.5 tons up to 5 tons for residential use. We want to determine the proper size needed to adequately cool your house when the temperature really gets hot.
There are two types of refrigerants most widely used in our industry. The first is R-22. R-22 has been the refrigerant of choice by many manufactures for the past 40 years. It has been reported that R-22 refrigerant is damaging our earth’s ozone layer and contributing to global warming. As a result, a new refrigerant named R-410a has hit the market. This environmentally-safe refrigerant is definitely the refrigerant of the future. The federal government has mandated to ALL manufactures, that as of the year 2010, R-22 will not longer be used in new air conditioning units. In fact, the federal government has a mandatory phase out plan for the production of R-22, ending production in the year 2020. The question comes up all the time, ‘if my existing air conditioner uses R-22, can I replace the refrigerant with R-410a?’ The answer is no. You must replace your equipment to accommodate the R-410a refrigerant. Keep this in mind when purchasing a new air conditioning system. We encourage our customers to purchase a system that accommodates the R-410a. R-22 system will soon be obsolete. But finally, the most important thing is to ensure yourself a good, tight and leak-free system by having your system installed by an EPA-certified technician from Manwill Plumbing and Heating Inc.
Condenser: Outdoor Unit
The purpose of the condenser is to house the compressor, condenser fan and condenser coils. Most condensers are approximately 30″ to 45″ in dimension and should be placed outdoors in a well-ventilated area. The fan on the condenser is designed to remove the heat from the hot refrigerant gases and allow the refrigerant gas to condense to a liquid form. Keeping vines and shrubs from blocking airflow through the condenser will help maintain lower operating costs.
Compressor: Heart of the System
The compressor is the heart of the air-conditioning system. Located in the condenser, its purpose is to compress the returning refrigerant, build up higher pressure and send the refrigerant back to the evaporator coil in your duct work to do it’s cooling. The two most common compressors are the scroll and reciprocating compressors.
The reciprocating compressor has been used in refrigeration systems for more than 60 years. It is comprised of a piston, crankshaft, piston rod, intake and exhaust valves. It is powered by an electric motor. All of these components are in a container smaller than a five-gallon bucket. Many consider the reciprocating compressor as the ‘old reliable’ in the industry.
The scroll compressor is unique in that it’s constantly compressing refrigerant versus the reciprocating compressor which needs to withdraw the piston for the next compression stroke. The scroll type of compression is done with two inter-meshing scroll plates that constantly rotate in the same direction. The scroll has fewer moving parts and operates very smooth. It also is powered by an electric motor and is rather compact. The scroll compressor has been widely used in our industry since 1982. It has proven to be VERY reliable and VERY efficient. In fact, most manufactures use the scroll compressor to achieve the higher SEER ratings. When shopping for a new air conditioner ask about Scroll compressors.
Compressor Warranties: Every manufacturer warranties products differently. The compressor should have a longer warranty than the other components. Most compressors have either a five or a ten-year warranty. Parts warranties will vary from one to five years. Some may even have 10 year parts warranty!
Protection and Safety Devices
Protection devices are components designed to protect your air conditioning compressor. The compressor being the heart of the system, it is very expensive to replace. When checking into a new system ask if these devices are included.
Filter/Dryer: Designed to filter out contaminants or moisture that may enter the refrigerant system during installation or servicing.
High and/or Low Pressure: Switch Senses the refrigerant pressures and protects the compressor against undue stress caused by excessively high or damaging low refrigerant pressures.
Time Delay Relay: This prevents the short cycling of the compressor. A compressor that is allowed to turn off and be immediately turned back on is subject to extreme stress. A time delay relay ensures the compressor will remain off for at least 90 seconds before restarting. Most programmable thermostats also have a time delay built into them.