ARE 5.0 - PPD - MECHANICAL SYSTEMS LATEST 2023 GRADED A

ARE 5.0 - PPD - MECHANICAL SYSTEMS LATEST 2023 GRADED A Net Zero Structure A building that consumes only as much energy as it produces on site through renewable means Selection of Fuel Type Depends on Fuel's availability in the region and the dependability of supply; the fuel's cost, cleanliness and convenience of storage; and the needs of the building's equipment Natural Gas Of all the fossil fuels it is the most efficient - it is clean burning and relatively low in cost It's heat value is 10,050 Btu/gal Flammable gas, consisting largely of methane and other hydrocarbons, occurring naturally underground (often in association with petroleum) and used as fuel. Propane A type of gas that can be used where natural gas is not available. It's heat value is 21,560 Btu/gal It is delivered and stored in pressurized tanks. Oil Is produced in six grades. Grades with lower numbers are more refined and more expensive. It must be stored in or near the building where it is used. No. 2 is the grade most commonly used in residential and light commercial boilers. It's heat value is 137,000-141,000 Btu/gal No. 4 & 5 are the grades used in larger commercial applications. It's heat value is 146,800-152,000 Btu/gal Electricity An energy source that is easy and relatively inexpensive to install, simple to operate, easy to control and flexible in zoning. It does not require storage facilities, exhaust flues or air supply. It's biggest disadvantage is cost, especially at peak-use times Steam Not considered a basic fuel like oil and gas, but it is available from a central plant and is distributed as a by-product of the generation of electricity. It is not used directly for heating but is piped into a building and used to heat water or air heating systems. Heat Pumps Heat spontaneously travels from warmer location to cooler ones. This device can reverse this, absorbing heat from a cooler location and transferring it to a warmer one. It can provide heat in the winter and cooling in the summer. In the summer, it acts like a standard air conditioner, with a refrigerant absorbing heat from the inside air through the evaporator, which than flows to the condenser where it releases the heat to the outside air. In the winter the refrigerant flow is reversed so that the heat pump absorbs heat from the outside air and releases it to the inside - though the heat pimp's efficiency decrease as temperature drops outside. At 40 degree or below it is not efficient - thus more effective in mild climates like Texas. Natural Energy Sources Energy from natural sources sun, wind, tidal and geothermal. Degree Days A rough measure of how much heating is needed for human comfort in a particular location over the course of a year. It is calculated for a given location by taking the difference between a baseline indoor temp of 65 degrees and the average outdoor temp for that day. Ex. On April 1 in Philly, the average out temp is 36 degrees. Take 65-36 = 29 degree days. (Outdoor temps over 65 = 0) Add the daily values for the year to get the total number of degree days for the year. This number is then used