3) Quonset greenhouse.

 The required data to estimate the heat losses in this type
of greenhouse (Figure 3) are:

 3.1) House width (W): This is the width of the greenhouse
 in feet.

 3.2) House length (L): This is the length of the greenhouse
 in feet.

 3.3) Rafter length (R): This is the length of the rafter in
 feet.

 3.4) Gable height (G): This is the height of the gable in
 feet.

 3.5) U factor of rafter material: This is the heat transfer
 coeffici-ent of the rafter's material in BTU/hr F ft2.
 Values of this coefficient for typical materials are
 shown in Table 1.

 3.6) U factor of roof material: This is the heat transfer
 coefficient of the roof's material in BTu/hr F ft2.
 Values of this coefficient for typical materials are
 shown in Table 1.

 3.7) U factor of the perimeter: This is the heat transfer
 coefficient of the perimeter material in BTU/hr F ft2.
 Values of this coefficient are shown in Table 1.

 3.8) Number of air exchanges per hour: This is the number
 of times that the volume of air in the greenhouse is
 replaced per hour. Typical values can be seen in
 Table 2.

 3.9) Temperature difference: This is the difference between
 the nightime inside desired temperature and the minimum
 expected outside temperature. This value is given in
 degrees Fahrenheit.

 Output

 The results of the program consist of the computed values
of conduction, infiltration, and total heat losses. Results are
expressed in BTU/hr.
 Conduction may be viewed as "the transfer of energy from the
more energetic to the less energetic particles of a substance due
to interaction between the particles" (Incropera and DeWitt,
1981).
 In the case of the greenhouse conduction heat losses are due
to the difference between inside and outside temperature. These