(7) Alarm system. It is recommended that there be an audible alarm wired to the dehumidification system to
warn of equipment failure. Care should be taken not to locate it in the general area of the dried air outlet.
(8) Dehumidification equipment replacement parts. It is critical that humidity is not allowed to exceed 50
percent; therefore, any down time of the dehumidification unit should be kept to an absolute minimum. To ensure that
this is so, the procuring activity should consider purchasing essential replacement parts as recommended by the
manufacturer of the dehumidification unit.
(9) Dehumidification equipment maintenance. Units should be inspected weekly to ensure smooth operation.
The manufacturer's maintenance schedule should be followed for lubrication, belts, filters, etc. The humidistat must be
calibrated according to the manufacturer specifications.
5-7. Controlled Humidity Buildings
a. Controlled humidity buildings. These are permanent buildings sealed against water seepage, water vapor
transmission, and air leakage. Only sound buildings with a limited number of openings and with a limited ratio of wall
area to floor area or volume can be economically sealed and dehumidified. A sound, built-up roof is required. All doors,
windows, ventilation, and other openings not required for operational purposes shall be secured and sealed against water
vapor transmission and air leakage (fig 5-1).
Figure 5-1. Example of Daily Water Vapor Load in a Controlled Humidity Warehouse