Exoten und Garten Forum
Hardy Palm and Subtropical Board
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Re: Not the point
Message from Rob Cookeville Tn
Precipitation, elevations, melting snow, solar radiation, industrial, flowering and harvesting dates, use of electrical power for heating or cooling in cities, air-conditioning service for optimum comfort, agriculture, architecture, power generations all can cause heating or cooling demands no matter where the location is noted and as for state lines or regions, these are approximate in my opinion and you can throw the zones out the window with this map because the only differing is heat requirements especially in the lower 'zones'.
Heating/Cooling degree days are defined relative to a base temperature and Because the base temperature can be chosen and it can therefore vary, the base temperature used in calculating the heating degree days has to be presented as per each defining reason. This information can be found anywhere if anyone has questions to the validity.
However, for structural debating in this thread, there is a theoretical approach as the level of insulation of a building affecting the demand for heating. For example, temperatures often drop below the base temperature during night (daily low temperature in diurnal variation), but because of insulation, heating is unnecessary.
In the end of spring and in the beginning of fall or in the winter depending on the climate, sufficient insulation keeps the indoor temperature higher than the outdoor temperature with little or no heating.
For example in southern California, during winter, heating is not so much necessary in Los Angeles and San Diego if the insulation is sufficient to take into account the colder night temperatures. Also, buildings include thermal mass such as concrete, that is able to store energy of the sun absorbed in daytime. Thus, even if the heating degree days indicate a demand for heating sufficient insulation of a building can make heating unnecessary.
Hope this helps some.
Exoten und Garten Forum Hardy Palm and Subtropical Board