I had a call from a marketing lady last October (I often get such calls) who wanted to pick my brain as to what would happen when our industry had to provide residential air-conditioning units with a minimum of 13-SEER efficiency. She didn't tell me who she represented or why she was asking. I thought you might be interested in my reply.

Happily, this is one of the battles that I personally won, and since nobody else will give me the credit (or blame), let me point out that when our industry was insisting that the new minimum be set at 12-SEER, I'm the one who wrote the only article calling for it to be set at 13. Boy, that stirred up a hornet's nest, and I don't know why, because nobody who wrote to castigate my intelligence seemed to have a vested stake in the outcome.

As I pointed out then, the higher the minimums are set, the better story we have to tell when it comes to explaining to people why they should replace their old systems - so who should object to that?

Anyhow, the lady was very interested in what the higher efficiencies would do to the prices of the equipment. I'm sure that many of you remember the same concerns when we went to 10-SEER. Then, fortunately, new compressor technology came along at about the same time (scroll compressors), so few manufacturers had to do much more than upgrade the compressors, strip the frills from their better 10-SEER models, and (other than for normal rises in material costs) the new 10-SEER “builder models” didn't really see much of a price increase over the older 6- or 7-SEER systems. So, has technology come to rescue the manufacturers again? I think so, but it doesn't appear as though most have taken advantage of it - they just made the condenser coils larger or deeper. Yet, one manufacturer (York) solved the problem of keeping the units smaller by employing a new type of coil. And while they are currently charging more for their lines that use the new coils, there isn't that much difference in the actual manufacturing costs.

And while another manufacturer (Nordyne) came up with a more efficient compressor (a rotary design from Panasonic), they chose to use it on just their top-of-the-line models. Also, over the past couple of years, Copeland has come up with a rather simple idea to add variable capacity to their scrolls and raise efficiencies. So you see, the new technology is there and available.

At the time I received the lady's call, I also suspected that all the HVAC manufacturers would have switched over to the new R-410A refrigerant by now, since nobody in their right mind should want to buy a unit with refrigerant that will be gone in just nine years. But, the American public is still largely unaware of this ominous problem, and manufacturers are too worried about missing replacement condenser sales to make the needed change.

Yet, even this refrigerant is new technology that could help them out, because the HFC blend automatically raises efficiencies - and Carrier really didn't have much of a price increase when they introduced their R-410A (“Puron”) units several years ago.

Another thing the lady was curious about was whether suppliers would be stocking up on the older 10-SEER units, so they could sell them at a lower price when the higher efficiency units got here. Did you do that, and was it a successful sales strategy? If so, tell me how it all worked out and maybe I'll write about it in some future article.

Now, wouldn't it be wonderful if more contractors would get smart enough to know what a great story they have to tell customers about why they should replace their old air-conditioning units? Oh well, you can only lead a horse to water.

Ten Things You Wanted To Know About Air Conditioners (But Were Afraid To Ask)

1. Q: What is a ton of air conditioning?
A: It is the amount of cooling you would get from a one-ton block of ice if it all melted over a 24-hour period.

2. Q: How do Btus relate to tons of cooling?
A: A ton of ice provides 288,000 Btus (British Thermal Units) in a 24-hour period. Air conditioners are rated in Btus per hour (Btuh), so 288,000/24 = 12,000-Btuh (or one ton), two tons is 24,000 Btuh, three tons is 36,000 Btuh, four tons is 48,000 Btuh, and five tons is 60,000 Btuh.

3. Q: What is SEER?
A: SEER stands for Seasonally-adjusted Energy Efficiency Ratio. It is a federally-mandated rating that provides an air conditioner's typical energy efficiency in an average climate. The number shows how many Btus of cooling the air conditioner will provide for each watt of electricity it consumes, so the higher the number, the fewer watts of electricity consumed and the lower the utility bill.

4. Q: Are there different requirements for air conditioners in the North than there are for those in southern locations?
A: All air conditioners come off the same assembly lines, so there are no differences in the same models. However, the furnaces (that must blow the cool air) are larger in the North and smaller in the South. So, the smaller furnaces in the South must be selected to provide the necessary higher air volume that is required for larger air conditioners.

5. Q: Which is better - floor-mounted air ducts and diffusers or ceiling mounted?
A: Once again, this is a matter of geological location and weather. Heat rises, so floor-mounted ducts and diffusers are best located at floor level where heating is the primary concern, since the rising warmer air tends to pick up and distribute the cooler air on the floor. On the other hand, where cooling is the primary concern, ceiling mounted ducts and diffusers are the best choice, since they tend to blow the warmer stratified air at the top of the room down toward the floor, providing a more even temperature throughout the room.

6. Q: What is Freon?
A: Freon is a DuPont registered trade name of a line of chlorine-based refrigerant gases that are scheduled to be, or have already been, phased out by federal legislation. There are other registered trade names for these same products, but they have never been as popular as Freon.

7. Q: What is Puron?
A: Puron is a Carrier Corp. registered trade name for R-410A, an environmentally-friendly non-chlorine-based refrigerant. The same product is being used by virtually all manufacturers in some lines of their air conditioners, but they can't call it Puron.

8. Q: What are the differences between “builder model” air conditioners and higher-end systems?
A: Efficiency, quality, sound, and appearance. While all air conditioners are designed to make it through the typical five-year compressor warranty period, systems that are more expensive usually provide higher efficiency, they have lower noise levels, they usually look nicer and have a wrap to protect the outside coil, and they have more and better components.

9. Q: Can someone estimate the proper size air-conditioning system for a house by its square footage alone?
A: No, there are too many design variables.

10. Q: Is the refrigerant in an air conditioner a liquid or a gas?
A: It's both. When it leaves the compressor, it's all gas, but when it leaves the outdoor coil, it's all liquid. Then when it enters the indoor coil, it's mostly liquid, and when it returns to the compressor, it should be all gas. The cooling process isn't created by moving gas, but by compressing gas into a liquid and then allowing it to evaporate inside the system.