A New Reality, Yet Again
The folks over at Knowledge @ Wharton, The Wharton School of Business at The University of Pennsylvania have nailed a crucial aspect of the current economic crisis with an article on how it is inordinately tough on older managers. The thing that is especially hard about this is that many of us, as we navigated the route to success or survival, found our way by specializing. We went or were led into unique careers that increased our value. The last twenty to thirty years has seen an unbelievable surge in managerial and technical specialization, and in independent consultants. This has not been a case of foolish people following dead end paths. It has been the prophetic invisible hand at work. We did it because it made sense, intellectually and financially. However, given America’s turn away from manufacturing, the global financial crisis, and the light-speed growth of technology, many of us are now at a disadvantage. We are in a sense tradesmen with no place to ply said trade.
The impact for those of us closely tied to manufacturing is obvious. But this downturn is not so selective. It appears to be affecting everyone. It not a select industry or specialty group that is feeling the brunt this go-round. This is an equal opportunity recession. It is affecting the banker and the backhoe operator, the engineer and the trucker.
You will notice my emphasis here is a human resources one. I’m not even getting into the macro-economic side of this, although I am very interested in and equally confused by that. What I am finding as a business owner is that it is not any easier than when I was an employee. The bottom line is still the bottom line, still important, and still directly related to my paycheck. I am like any of the other middle aged managers mentioned in the Wharton article. I need to diversify, find other opportunities, make myself more valuable yet again. The big challenge is, given the current environment, how do I go about that?
How indeed!
Steam Coil Freeze Protection
A major problem with heating with steam is the potential for coil freeze. A necessary byproduct of steam is condensate, or water. This is in theory a good thing as it indicates that the process is working. As the heat from the steam is transferred to the medium, in this case airflow, the steam condenses back to water. At this point it should be removed from the system via the steam trap, and in an ideal world this always happens. However, we all know about the ideal world.
The typical freeze scenario comes into play because of system stall. Conventional steam coil design utilizes a modulating valve to control steam flow. Now, while I note this is conventional design, it is not necessarily optimal design. In most cases of using steam in HVAC applications I recommend the Integral Face and Bypass Coil, as noted in a previous entry. However, that design is not in itself always optimal, or always utilized; in which case the designer, plant engineer, or technician must deal with the situation at hand. As it stands, conventional design utilizing a modulating valve will run into trouble at the point the valve begins to close as demand is satisfied. If in this situation the valve closes so that downstream pressure is equal to or greater than upstream pressure the coil will be in a condition of stall. The condensate will accumulate in the coil and is thus subject to freezing.
My choice solution for an existing conventional system is to utilize a freeze valve that will sense the water and remove it. I use the Thermomegatech HAT valve with a setpoint of 100 Deg. F. I install the valve in the condensate line between the coil and the strainer and/or steam trap. I pipe the condensate to drain. I have seen similar devices used by the steam specialty companies that were marginal or ineffective. The primary reason being they had a setpoint in the area of 35 Deg. F. This is too low and too close to freezing temperature. The condensate may not be able to escape the coil before freezing. On the other hand, having a setpoint of 100 F. seems to work well. 100 F. is way too cold for condensate, which should typically be over 210 Deg F., yet it is warm enough the condensate won’t freeze.
I have had positive results with this system. While it is recommended for conventional steam heating, it can be applied in most applications where freezing condensate or system stall may be a problem. Another problem with system stall outside of freezing is the introduction of air and non-condensables into the system through the vacuum breaker. This is often seen in process heat exchangers utilizing modulating valves as discussed above.
The Handbook of Air Conditioning and Refrigeration, Free
Mohamed Fawzy has provided a link to a free download of this comprehensive and very large (1401 pages) book here:
Thanks, Mohamed!