Air Conditioning / Heat Pumps
The field of air conditioning and heat pumps – the transfer of heat via refrigerant gas – is the scene of dramatic advances in technology and efficiency. In most replacement situations today, both indoor and outdoor sections must be included as even slightly older units have incompatible technologies or refrigerant gases.
Efficiency is measured on the SEER scale – Seasonal Energy Efficiency Ratio. It’s an arbitrary set of numbers in which each point represents a 10% increase in efficiency over the preceding point. As such, it’s a scale of diminishing returns, as one goes up the scale 10% is deducted from a steadily declining base. Most air conditioning systems in the field today are 9-10 SEER, and the minimum now available is 13 – a great improvement. SEER ratings of 15 and 16 are readily available, but beware ratings advertised as “up to” – they often apply to component match-ups unsuitable for actual usage!
Variable speed technology is at the heart of recent advances. Sophisticated motors and circuit boards control the flow of heating or cooling at a rate aligned with demand. Zoned systems can match exactly the demand in one or all of the areas covered. Relatively simple combinations with a variable speed blower can offer great returns.
EFFICIENCY - The cost of operation, it is measured on the SEER scale (Seasonal Energy Efficiency Ratio). Each SEER point is a 10% improvement over the preceding point. Most current units from the 80’s and 90’s have a 10 SEER rating. The current minimum rating is 13, a 27% improvement in operating cost over your old unit! Note that the SEER scale is one of diminishing returns, taking 10% from a steadily declining base so that the difference between 10 and 13 models is much more than 13 and 16 models (27% vs 20%).
CAPACITY - This is measured in the tonnage of the unit. Each ‘ton’ of cooling equals 12,000 BTU’s of cooling power. Your salesman will determine the appropriate sizing for your needs - too little and your house won’t cool on the hottest days…too much and it won’t dehumidify on our frequent ‘85 and muggy’ days.
FAN PACKAGE - Your air conditioner may be tied to your furnace in the basement, or to a fancoil in the attic, but either way it must have sufficient airflow to deliver cooling throughout the house. One of the greatest efficiency gains in modern systems came from the development of the ECM motor, which can add 10% efficiency to any unit. Variable output fans can adjust air delivery to conditions, improving cooling or dehumidification as needed.
In 1939 Carrier introduced residential home cooling to the world at this igloo pavilion at the World’s Fair in NYC. Since then systems have seen improvements in size, performance, efficiency, and price, and now, matched with the right Carrier furnace, provide home comfort unimaginable to those who visited the “igloo.”
1939 WORLD’S FAIR Carrier Pavilion