Answers to sample exam questions

        1. Section 304.51 fuel gas code

        Standard method- Room must have a volume of 50 cubic feet per 1000 btuh of installed appliances for combustion or have outside air brought in.

        An 80,000 btuh appliance has 80-1000’s (80,000/1000 = 80) Therefore, the room must have 80 x 50 cubic feet or at least 4000 cubic feet. This room has a volume of 20 x 18 x 8 = 2880 cubic feet. Since the appliance requires 4000 cubic feet, the room is in a confined space and needs outside air

         

        1. Read section 403.3.1.1 then go to Table 403.3.1.1. The Table says there will be 5 occupants per 1000 sq. ft. 1700 divided by 1000 = 17 . 5 x 17 = 85 occupants. Furthermore, the Table says we need 5 cfm outdoor air per occupant, thus 85 occupants x 5 cfm = 425 total cfm must be introduced into the office.

         

        1. When the height of a chimney falls between two choices in the vent sizing tables always select the lower height. Using the higher chimney will result in under sizing

         

        1. Velocity = CFM / area in sq. ft. 8” x !4” = 112 sq. in.    convert area to sq. ft.  112 sq. in. / 144 = .777 sq. ft.

         

        Apply the formula above    vel = CFM/area       vel = 88/.777 = 1030 ft. per min. (rounded)

         

        1. When dealing with R values or U values always convert everything to R values, then, convert back to U value, if needed.

        The U value of the existing insulation is .05. Therefore the existing R value is 20 (1/.05),  20 +19 = 39 new R value; 1/39 = .025 new U value

        1. I’m not going to go into a lot of detail about calculating sales price at various profit margins, as the rationale is discussed in greater detail in my prep course.

        To calculate the sales price according to standard accounting principles, (1) start with 100%, (2) deduct the profit you wish to obtain (3) divide your cost by the resulting percent

                        1.00 – .30 = .70,      $1000/.70 = $1428.57 sales price

         

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