I am working for a project and i want to calculate the savings in energy in terms of reduction in AC consumption when reflective materials are applied on houses.These reflective materials lower the temperature of the room .
While in many places the color of the cap on a hydrant will be one of four colors (black, white, green and yellow) to indicate the flow rate according to a national standard, the hydrants currently in use in NYC are all of two general types. While the flow rate between varies somewhat, as do the connections, they differ enough in appearance that it's obvious which is which. Additionally, the Smith hydrants the ones that have the larger cap on them have a number on the barrel that indicates the size of the main that's feeding the hydrant. If the number is underlined, it's a dead end main, being fed from only one direction so will have lower flow than normal. (As usual, there's an exception to the rule: a different type of hydrant used only in the part of the city served by the Jamaica Water Company, but those are being phased out and replaced.) So the point is that basically the city or FDNY could paint them any way they want to. Most likely the black enamel is the cheapest to apply and maintain.
Melamine formaldehyde resin is approved by the US FDA for direct food contact for human consumption. See reference below. The cured polymer does not off gas formaldehyde. Polymers made with formaldehyde can off gas unreacted formaldehyde soon after they are manufactured; but it is long gone by the time the polymer leaves the plant.
