Controlled Humidity Protection Program
CHP is a field-tested, time-proven maintenance technology that is designed to eliminate moisture-induced damage and the resulting sustainment costs. Modern technology has made this concept applicable to equipment throughout its spectrum of operation and its lifecycle. By maintaining relative humidity (RH) below 50%, the adverse effects of humidity are eliminated, including rust, mildew, mold and moisture. Above 50% RH the rate of corrosion growth shifts from linear to exponential. A CHP system is an environment stabilization system with four major components: air dehydration units, air distribution equipment, shelter/hull and a control system. The shelter/hull component can be tailored to meet operational requirements in the most cost effective manner. Examples of shelter/hull configurations include LAVs, tanks, metal and tension fabric shelters, and existing buildings. This program is designed as a means to evaluate and approve CHP technologies for operational and storage applications. Dehumidified protection is the preferred method of storage. The deferral of preventative maintenance checks and services for equipment stored in CHP is authorized as defined in the CPAC Handbook.
Equipment Storage Methods
NSWCCD is performing a limited research and development task aimed at determining the potential reduction in corrosion resulting from protected storage methods at each of the MEFs. In this study, warehousing or garaging showed a reduction in corrosion by a factor of 65X over uncovered storage for corrosion test coupons. The first year's data collected at Camp Lejeune tracked corrosion of steel in an open lot, under roof cover only, in a warehouse and in dehumidified storage. Corrosion rates were:
- Open lot = 1.31 mils per year
- Under cover = 0.55 mils per year
- Warehouse = 0.02 mils per year
- Dehumidified = 0.01 mils per year
While dehumidified storage has demonstrated reductions in corrosion maintenance costs for the National Guard, substantial initial investment and continuing costs (electricity and dehumidifier maintenance) are required to achieve this benefit. The preliminary test data suggests that garaging alone will show similar or equal benefits.
Facility Identification - Facilities will be identified or purchased for garaging a minimum of 10-12 HMMWVs and 5-ton trucks at Camp Lejeune and/or Kanahoe Bay. As part of this effort, an evaluation of using covers with detachable dehumidifier hoses for individual vehicles or groups of vehicles will be conducted.
Vehicle Documentation and Coupon Installation - The condition of vehicles intended for garage storage and an equivalent amount to be stored outside will be documented. Corrosion monitoring coupons will be installed on both sets of vehicles.
Performance Monitoring - Both sets of vehicles will be monitored for corrosion performance for a period of up to 3 years. Sets of coupons will be removed yearly and measured to quantitatively determine differences in the corrosivity of the environment to which the vehicles were exposed.
Storage Method Analysis - The data collected will be analyzed to determine the most cost effective method of vehicle storage. Costs to construct warehouses, procure and maintain dehumidification, etc. will be included in the analysis. Results will provide justification for greater MILCON funding for warehousing at all of the MEFs should this be identified as the most cost effective method.