Feedback: You Can’t Fool Mother Nature, Breaking the Distribution Chain, When You Assume…
You Can’t Fool Mother Nature
I just read the article on the DOE’s efforts to raise SEER standards as a means of helping the “nation’s strained power system” [“DOE Efficiency Standards Scrutinized,” Oct. 9]. I am a “pointy-headed professor,” but I was hoping someone with more credibility in the real world would pass these thoughts on to someone at the DOE or ASAP [Appliance Standards Awareness Project] before they establish standards that do not specifically address demand problems.The “S” in SEER stands for seasonal, and machines can be (and have been) built that have high SEERs but poor efficiency when the outdoor temperature is high. Several years ago a major manufacturer sold a variable-speed heat pump. The 3-ton unit had a SEER of 15.2 but the EER fell to 8.8 with 100°F outside air. The same manufacturer had a constant-speed product with a 10.3 SEER but it actually had a better EER (8.9 at 100° outside air) than its higher-cost cousin.
How can this happen? Either take my word for it or get a copy of ARI 240 and look (in disbelief) on page 19 at the bin temperatures used to calculate SEER for a multiple-speed machine. The outdoor temperatures are actually lower than the indoor temperature for two-thirds of the time, but only 0.4% of those temperatures are above 100°. So if a marketing department told its engineering department to maximize SEER to keep customers and DOE officials happy, they can do it. However, making a big dent in efficiency when it’s over 100° outside is much more expensive, since you’re dealing with Mother Nature’s laws rather than a standard like ARI 240 that was put together by committee.
There are thermodynamic limits to efficiency with conventional equipment that can be hidden by things like SEER, HSPF, and kW per ton (in central equipment). If hvac professionals, the DOE, and ASAP are serious about “the strained power system and customers’ electricity bills,” they need to look more critically at actual performance data.
There are several wonderful technologies that can more effectively reduce demand and energy consumption. Our reluctance to more aggressively adopt these options is in part due to the failure to recognize the limitations of conventional equipment.
Steve Kavanaugh
University of Alabama,
ME Department
Breaking the Distribution Chain
Certain manufacturers are soon going to market their products to Home Depot. This will cut out the middleman and, at the same time, the end user or consumer is going to get the better deal at Home Depot. Are you surprised? That means the end user is going to get the product without the wholesaler and contractor. Manufacturers sure are going to get a higher profit than selling their product to the wholesaler and then to a contractor. Is this way we want to do business? Surely not. If you won’t open your mouth, one day soon your wholesaler will be going out of business. Think about this.Now let’s talk about you, the wholesaler. You also do the same type of business, don’t you? You wholesalers also sell directly to the consumers or end users. Tell me, what would contractors say and how will they react in this situation?
A good customer used our service for the last two years. Somehow, through a manufacturer, he knew about my wholesaler. Then he came directly to you, my wholesaler. My customer dropped me and dropped my service and gave his business directly to you. And you accepted it, you gave him the contractor’s price and you stepped on my feet and you created a relationship with him. Is this the way you do business?
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What kind of business policy is this, to sell to contractors and end users at the same price? If a wholesaler sells directly to an end user or consumer, we contractors should stop doing business with them. At the same time, manufacturers who do business with retail chain stores such as HD, the wholesaler should also stop doing business with them. And consumers who buy directly from the manufacturer, wholesaler, retail chain stores, or any other source, a contractor should charge them higher prices than normal.
We all have to change the way we think.
Let’s not step on someone’s feet or someone’s business. Instead, let’s all unite and share the profit in doing good, respected business.
Miguel Barreto
Refrigeration Service Plus
Union City, NJ
When You Assume…
I don’t have time to write this to you. (The “Cat’s in the Cradle” song is playing in my mind.) After rereading the July 10 issue, I have two comments.There are articles that deal with HRVs, humidifiers, heat load calculations, and some other issues. We, as an industry, are pulling a noose around our necks every time we make an assumption. In this case, it’s an assumption about infiltration.
Comfort conditioning is a dynamic process. This means changing one item changes the entire design of the system and, I would say, the structure it is meant to affect. Stop saying, “Houses are being built tighter and tighter.” That is an assumption! You don’t know if a house or structure is tight until you test.
In the “humidifier” article [“Avoid Common Mistakes in Humidifier Installations”], the author emphasized proper sizing. The ability to humidify is based on the winter infiltration rate.
In the HRV article [“HRVs Can Be a Profitable Accessory”], the need for fresh air circulation was emphasized. In my market, the greatest need for infiltration is in the summer, as it is almost anywhere else. Using an HRV could be disastrous in these structures, inducing 70% rh around the clock and increasing the load. I know by experience. We have “new heat load calculations on the way.” They are “estimates at best,” the article says [“New Load Calculations Are Coming Your Way”].
All this stuff is based on modeling. The ability to use modeling is to have an experience base that tells you when you are close to home and when you are missing something. Stop and think carefully before you specify equipment and accessories. Make sure you are taking the complete latent load into account. Residential contractors are especially guilty of this. There are so many variables, it is overwhelming, but manufacturers are offering you rated matchups that will not dehumidify.
An in-depth study of the engineering tables will show you what the coil will do with the condenser you are using at the rated cfm. Look carefully. Get the information for the air mover you are using. You may not be able to generate the rated cfm. And the ductwork will need to cooperate. Most of the time it doesn’t. If you sell high efficiency on a duct system designed for minimal airflow, you are setting yourself up for a bad reputation. “My reputation will take years to catch me in this market,” you say. Maybe so, but be careful — “Your sins will find out!” If you are designing ductwork and you haven’t memorized Manual D, please stop and go read it.
Here is my second point. There was also an article [“Hollywood Complex Is Contractor’s Glamour Job”] about a job in Hollywood. What good is a building if you can’t heat and cool it? We should tell the architects to tie a rock around their necks and dive off a pier when they bring us plans with no thought for the mechanicals. We need to start steering the boat! The health of our neighbors and friends depend on it. Hvac is the premier high-tech industry. Computers can’t run without us.
Let’s send word to the manufacturers, “Stop marketing equipment to the end user; what they really need is an installationFinally, to my brother contractors, you are in control. When you receive a request for a bid, have a minimum standard for what is an acceptable installation. Don’t ask your team to shove an inferior design into a superior structure. Let’s put something in that will work for the next 150 years or so.
John Compton
Home Excellence, Inc.
Reston, VA
Publication date: 10/23/2000