HVAC Efficiency in Clarksville, IN, Jeffersonville, IN, Louisville, KY and the Metro Region
When people speak of the efficiency of a system, they are not referring to how well it heats or cools, rather they are referring to how much it costs to produce heating or cooling. The government mandates the minimum efficiency of most appliances, including all heating and air conditioning equipment. (This is the yellow sticker that you see on appliances.)
Regardless of how efficient your system is, the most important factor in determining how efficiently it works is how you operate the system and what kind of regular maintenance it receives. The most efficient system cannot cool the house if the windows are open or if the filter is dirty! Aside from common sense and regular maintenance, the factors in determining how well a system operates are covered by system design.
EFFICIENCY: Furnaces
80% is the minimum efficiency of a new gas furnace and has been for some time. Basically stated, an 80% efficient furnace will heat your home as well as a 95% efficient furnace, it will simply cost more to operate. An 80% efficient furnace will cost you $1 to get 80 cents worth of heat and a 95% efficient furnace will give you 95 cents worth of heat for the same cost. Manufacturers accomplished the increased efficiency by sealing the combustion chamber, thus preventing the heat from escaping up the flue.
This process resulted in two things: the flue gas is not as hot and is now vented out a PVC pipe instead of a double wall metal pipe, and, the furnace creates condensation like an air conditioner requiring a drain connection. Whenever possible you should consider upgrading to a 95% efficient furnace. Regrettably what this means is that even if your 15 year old, 80% furnace is working perfectly fine you should consider replacing it with a 95% efficient furnace because you will recoup your investment in energy savings in a reasonable period of time. If you have a 60% efficient barometric furnace or a gravity furnace then it becomes a complete no-brainer as to whether you should replace it or not.
EFFICIENCY: Condensers/Heat Pumps
When you look at the efficiency of condensers or heat pumps it is less straight forward, the efficiency of these units is stated as a SEER rating. This is an energy efficiency ratio. 20 years ago the standard efficiency was something like 8 or 9, then it went to 10 for many years, then in January 2010 the standard efficiency became 13 SEER, then a couple of years later went to 14 SEER. So, a 14 SEER system is actually a very efficient system historically speaking.
Manufacturers have systems that are rated as high as 21 SEER. When deciding what kind of system to purchase you will want to consider the SEER rating. If money is no object and you want to reduce your carbon footprint as much as possible, then you should consider buying the most efficient system possible. However, the additional cost of these very high SEER systems cannot be recouped in energy savings. (Each SEER point saves you about 7% on your electric bill, though this does not necessarily mean that a 21 SEER system will reduce your electric bill 70% over a 10 SEER system!) It is a widely believed concept that it is a good investment if you can recoup your money within 5 years.
A 15 or 16 SEER system is priced close enough to a 14 SEER system that the additional cost can be recouped within the 5 year time span. A caveat to this is that to put together a 15 SEER or higher system you will have to replace the furnace as well as the condenser/heat pump and coil. A 16 or 18 SEER outdoor unit will not give you that rating all by itself, only in combination with certain evaporator coils and furnaces.
