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900
CHAPTER 43
1950Guidd
An approximation; of the useful life of various items of equipment, and parts of systems is shown in Table 5. It should be noted that if an appro priate maintenance item is not established, the rate of equipment deteriora tion may be substantially increased.
Interest
The interest chargeable may not represent the existing money rates. It may include an item to cover the diversion of capital or other items
Table 6. Owning and Operating Cost
First Cost
Cost of mechanical system___
Annual Service Cost
Electric Power Costs
Annual Fixed Charges
Amortization--Depreciation Interest rate 1%__ Amortization and Deprecia
tion FC Y Y 4* 1
Interest: -^y-- X / =
Annual Fixed Charges: (Tntal)
Annual Maintenance Costs
Lubricating oil and grease. Painting for corrosion pro
tection or other purposes__
Pumps--Condenser water.. Pumps--Well water__ - Cooling tower fans..!__ Cooling tower pumps.. Refrigeration machines. Miscellaneous or other..
f>M* 1
Oil--for boilers or Diesel
Steam For direct heating.
' For Ventilation--preheat-
For Ventilation--reheaters For Turbine driven equip
mentFor Engine driven equip-
Sewers Charges for discharging well water into public drainage systems. .
Annual Service Costs-- TOTAL
Summary
Annuel Maintenance Cost-- TOTAL
Annual Maintenance Costs Annual Owning and Oper-
depending on existing tax laws which may make it necessary to charge interest due to diversion of capital as a cost item. It should be noted that interest may be based on an unamortized balance. As an example, a 15 year amortization period with a 4 per cent interest rate will approximate a 2.1 per cent average annual interest rate.
Taxes
The taxes chargeable will be the proportion of property tax caused by the increased valuation of the property due to air conditioning.
Owning ami Operating Costs
901'
Insurance
The rate for insurance may vary Considerably depending on the type of structure in which the equipment is located and upon other governing factors. A rate of about $0.60 per $1,000 may be considered as being representative for normal installations.
Rent
'
If the equipment under consideration is to be located in rented or leased quarters, it may be necessary to include an item-for space rental.
An orderly arrangement of the various components of owning and oper ating costs, which will also serve as a check list to forestall inadvertent omissions, is illustrated in Table 6. The formulas for computing amortiza-
tion and interest are given in the table. - Interest should be computed on the undepreciated portion of investment only.
MAINTENANCE COSTS
~ Maintenance costs include-replacement parts and the labor required for making repairs, replacing parts, cleaning, painting, etc. It should be noted
Table 7. Approximate Maintenance Cost fob Large Air Conditioning . Installations, Using High Qualitt Equipment
Dollars per Ton per Year
0.60 0.26 0.07 ; 0.25 0.85 0.15 1.15
that major overhauling or complete replacement may restore the capital value of certain iteius.Qf equipment,, and in such cases the costs incurred may not necessarily be charged as maintenance coste. Generally, routine labor requirements will be the function of an operating engineer or staff, and the responsibility of this group may extend beyond the equipment being discussed here; hence, it is important to.include only an equitable share of the ; time of this group. Extraordinary repairs involving special machinery will Usually be covered by contract with equipment service divi sions, and should be accounted for oh that basis.
Many of the items J included in maintenance; costs are highly variable and depend on the type and quality of the purchased equipment. For large air conditioning'installations, using high quality equipment, some approximate; costs per ton are given in Table 7.
In addition to the costs listed in Table 7, consideration should possibly be given to other items such as: water treatment for boilers; other "boiler and heating plant cleaning and repairs; repair and replacement of,heating plant valves, traps, and vehts; water treatment for cooling tower or chilled spray water; drive belts, possible damage due to freezing weather; cleaning of air ducts; and repairs to insulation. ` .