In estimating for heating with hot water, all pipes and fittings must be taken off and listed, all standard radiators priced by the square foot of radiation, and special radiators listed separately, also tanks, valves, hangers, etc.

Radiators are listed in the trade catalogues, together with the number of square feet in each section.

These prices are subject to varying discounts which can be obtained of the manufacturers.

Radiation. The amount of radiation necessary for each room depends upon so many varying conditions that all rules are in a way approximate.

Certain formulae may be used, which will give good results in ordinary cases, but just what allowances are necessary must be determined by the heating engineer.

The same is true of making the estimates of hot water or steam and the contractor should in all cases have the job figured by an expert.

In ordinary cases the amount of radiation may be determined from the cubic contents of the rooms to be heated by the following tables which give the proportions of one square foot of radiating surface to the cubic contents of the various rooms in cubic feet.

STEAM

One Square Foot of Radiation Will Heat

Dwellings, Cubic Feet

Halls,

Stores, Etc.

Cubic Feet

Churchesand

Auditoriums,

Cubic Feet

By direct radiation -

On first floor...

35 to 60

75 to 100

125 to 200

On upper floors...

50 to 80

...

..

By indirect radiation -

On first floor....

25 to 40

50 to 70

80 to 135

On upper floors...

40 to 50

...

..

Hot Water

One Square Foot of Radiation Will Heat

Dwellings, Cubic Feet

Halls,

Stores, Etc.

Cubic Feet

Churchesand

Auditoriums,

Cubic Feet

By direct radiation -

On first floor...

15 to 25

30 to 45

50 to 85

On upper floors...

25 to 40

By indirect radiation -

On first floor...

17 to 40

45 to 65

80 to 125

On upper floors...

25 to 35

Having determined the amount of radiation, piping, and fittings, the labor may be obtained by adding about 20 per cent to the cost of materials.