MOC_510-1B_HVAC_Cleaning_.pdf

MOC-510-1B

October 2000

Supercedes

AMC-510-1A

August 1995

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION (NOAA)

MARINE OPERATIONS CENTER

STANDARD SPECIFICATION MOC-510-1B

HVAC CLEANING

1. SCOPE. This specification contains the general requirements for cleaning HVAC systems ducts, equipment and components on and for NOAA ships.

2. REFERENCES.

a. NOAA Standard Specification AMC-000-1(series), "General Requirements For Ship Repair Contract Work on NOAA Ships"

3. REQUIREMENTS.

3.1 General.

3.1.1 The Contractor shall provide all labor, material, services, tools, equipment, and supervision needed to accomplish the required work.

3.1.2 Remove all interferences necessary to complete the

required work. An interference is any structure, equipment, piping, sheathing, cable, insulation, or other part of the ship which interferes with access to the ducting or equipment being cleaned. After the work has been completed, restore the removed interference(s) to a condition equal to existing.

3.1.3 Some existing overhead panels on NOAA ships contain

asbestos. To the extent possible, the contractor should plan the work to avoid removal of asbestos-containing panels. Whenever asbestos-containing panels are removed to accomplish the required work, they shall be renewed with new non-asbestos panels of the same general appearance, rigidity and strength. Comply with section 4.11.7 of reference 2.a when removing and disposing of existing asbestos-handling panels. Contractors are encouraged to conduct a pre-bid inspection of the ship to determine how many, if any, asbestos-containing panels must be removed.

3.1.4 Prior to starting work, the contractor shall prepare and submit to the COTR or Port Engineer a work plan and schedule.

The work plan and schedule shall outline the location and methods of gaining access to ducts and components for cleaning, and the day and time specific sections of the HVAC system will be inoperable. As changes occur in the schedule, the COTR or Port Engineer shall be advised.

3.2 Ducting. The following requirements apply to cleaning of

heating, ventilation, and air-conditioning ducts.

3.2.1 Work shall be scheduled to minimize disruption of the

ships' HVAC system. On ships having more than one HVAC system, only one system shall be inoperative at a time. Restore all systems to full operation at the end of each work shift, except when work will continue immediately on another work shift.

3.2.2 The contractor shall use existing access openings in ducts to the extent practical. Where necessary, the contractor shall cut new accesses in the ducts. New access openings shall be sealed with new sheet metal covers, gaskets, and screws.

3.2.3 When cleaning ducting of systems that have hot and cold air mixing boxes and air flow control boxes, the boxes shall be opened, removed, disassembled, and otherwise protected as necessary to prevent components from being damaged by the high volume air flow required during cleaning. Steps to be taken to comply with this requirement shall be included in the work plan and schedule.

3.2.4 Ducts shall be cleaned of all dirt, dust, lint, grit, debris, and other foreign particles as follows:

a. Using a high-vacuum truck capable of pulling a minimum of 12,000 cubic feet per minute (cfm) through a 10-inch diameter duct, pull a high-volume reverse air flow through each section of ducting. While the high-volume air is being pulled through the ducting, the entire interior of the ducting shall be air blasted with a "skipper" hose delivering compressed air at a minimum of 125 psig.

b. For ducts having a cross-sectional area less than 75 square inches, the reverse air flow velocity shall not be less than 350 feet-per-second. This velocity is roughly equivalent to pulling 12,000 cfm of air through a 10-inch diameter duct.

c. For ducts having a cross-sectional area of 75 square inches and greater, the reverse air flow velocity shall not be less than that which can be created by pulling 12,000 cfm of air through the duct.

d. Take necessary precautions and steps to ensure that ducting and components are not collapsed or otherwise damaged due to the excess vacuum created when pulling the reverse air.

e. If required to obtain the required air flow in individual branch ducts, temporarily blank off the registers, terminals and other openings in other branch lines.

3.3 Clean the interior side of all fans, filters, coils, diffusers, dampers, mixing boxes, preheaters, heaters and other components in the specified HVAC system using solvents and brushes as needed to remove all dirt, dust, lint, grit, debris, and other foreign particles.

4. QUALITY ASSURANCE.

4.1 All cleaning shall be inspected and accepted by the COTR or Port Engineer prior to reinstalling access openings.

5. NOTES.

5.1 Reference 2.a may not be issued with all bid solicitations.

However, a copy of the applicable section will be provided upon request. Prospective bidders may obtain a copy by contacting the Marine Operations Center, Marine Engineering Division, 439 West York Street, Norfolk, VA, telephone (757) 441-6201.

END OF SPECIFICATION