P.O. Box 410
Schofield, WI 54476

Phone: 715.359.6171
www.greenheck.com

Product Specification Guide
Model MBD-15 Balancing Dampers
Facility Service Subgroup: Division 23 HVAC (Previously Division 15)

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Note to User: This document is subject to copyright protection and is proprietary to Greenheck Fan Corporation. However, Greenheck Fan Corporation authorizes the user a limited non-exclusive license to use this document or portions of it for the purpose of preparing written product specifications for the above CSI MasterFormat category. All information in this document as provided by Greenheck Fan Corporation is informational in nature and is provided without representation or warranty of any kind as to the user or any other party, including, without limitation, ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE, OR NON-INFRINGEMENT. To the greatest extent permitted by applicable law, Greenheck Fan Corporation assumes no liability, and User assumes all liability and risk, for the use or results from the use of this document or the information contained herein, whether as modified by the user or not. Users should consult www.greenheck.com to verify that this document represents the most current version.

Specifier Notes: This product guide specification is written according to the Construction Specifications Institute (CSI) Format - 2004 Edition.

The section must be carefully reviewed and edited by the Engineer to meet the requirements of the project and local building code. Coordinate with other specification sections and the drawings.

Delete all unnecessary "Specifier Notes" when editing this section.

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PART 1   GENERAL

1.1	WORK INCLUDED

A.	Galvanized steel balancing dampers suitable for application in HVAC systems.

1.2	RELATED WORK
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Specifier Notes: Edit the following list as required for the project. List other sections with work directly related to the dampers. ********************************************************************************************
A.	Section 233300 Air Duct Accessories (Formerly 15810 – Ducts) 

B.	Section 230913 – HVAC Instrumentation and Controls: Actuators and Operators; Control Dampers (Formerly 15900 – HVAC Instrumentation and Controls: Connections to actuator)

1.3	REFERENCES
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Specifier Notes: List standards referenced in this section, complete with designations and titles. This article does not require compliance with standards, but is merely a listing of those used. ********************************************************************************************

A.	AMCA 500-D – Laboratory Methods for Testing Dampers for Ratings

B.	AMCA 511 – Certified Ratings Program for Air Control Devices

1.4	SUBMITTALS

A.	Comply with requirements of Section 01330 – Submittal Procedures.

B.	Product Data: Submit manufacturer’s product data.
1.	Include velocity and pressure drop.
2.	Indicate materials, construction, and dimensions.
3.	Include a copy of Installation Instructions.

1.5	QUALITY ASSURANCE

A.	Product is subject to set periodic testing to assure performance is maintained.

1.6	DELIVERY, STORAGE, AND HANDLING

A.	Delivery: Deliver materials to site in manufacturer’s original, unopened containers and packaging, with labels clearly indicating manufacturer, material, and location of installation.

B.	Storage: Store materials in a dry area indoor, protected from damage, and in accordance with manufacturer’s instructions.

C.	Handling: Handle and lift dampers in accordance with manufacturer’s instructions. Protect materials and finishes during handling and installation to prevent damage.

PART 2   PRODUCTS

2.1	MANUFACTURER

A.	Greenheck, PO Box 410, Schofield, Wisconsin 54476-0410. Phone (715)359-6171. Fax (715)355-6458. Web Site www.greenheck.com.

2.2	HVAC Balancing Dampers

A.	Model: MBD-15

B.	Ratings

1.	Differential Pressure: 
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•	Dampers shall have a maximum differential pressure rating of 4 in. wg.

2.	Velocity: 
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•	Dampers shall have a maximum velocity rating of 2000 fpm. 

C.	Construction:
1.	Frame: 
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Specifier Note: The following requirements for frame construction provide for specific corner reinforcement. A major problem with dampers is light or flimsy construction resulting in damper operating problems because they are installed out of square or racked. Corner reinforcement required by the following specification will significantly minimize these problems. To prevent excessive pressure loss across small dampers it is desirable to require a low profile frame to maximize the damper free area and minimize pressure loss. The following requirements address this issue be requiring a low profile frame on dampers less than 17 in. high.
Specifier, select one of the following:
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•	Damper frame shall be 16 ga. galvanized steel formed into a 5 in. x 1 in. structural hat channel. Top and bottom frame members on dampers less than 17 in. high shall be low profile design to maximize the free area of these smaller dampers. Frame shall be 4-piece construction with 1 ½ in. (minimum) integral overlapping gusset reinforcements in each corner to assure square corners and provide maximum resistance to racking. 

2.	Blades:
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Specifier Notes: The following requirements for blade construction incorporate a design concept known as VSB (Variable Symmetrical Blades). Many damper manufacturers utilize only one size of blade, which requires trimming one or more blades to accommodate varying damper heights. When blades are trimmed one or more of the blades become non-symmetrical resulting in operating torque that will vary significantly depending on airflow direction through the damper. Alternatively larger blade stops (top and bottom of damper) are required. This reduces damper free area and results in higher pressure loss across the damper. 
Specifier select one of the following:
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•	Damper blades shall be 16 ga. galvanized steel strengthened by three longitudinal 1 in. deep V-grooves running the entire length of each blade. Each blade shall be symmetrical relative to its axle pivot point, presenting identical performance characteristics with air flowing in either direction through the damper. Provide symmetrical blades of varying size as required to completely fill the damper opening. Blade orientation is horizontal. Blade operation is parallel or opposed.

3.	Blade Stops:
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Specifier Notes: The following requirement for blade stop construction minimizes blade stop height. Large blade stops reduce damper free area and results in higher pressure loss across the damper. 
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Each blade stop (at top and bottom of damper frame) shall occupy no more than ½ in. of the damper opening area to allow for maximum free area and to minimize pressure loss across the damper. 

4.	Linkage: Concealed in jamb.
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Specifier Notes: Linkage concealed in the jamb of the damper reduces pressure drop across the damper and results in less maintenance than on-blade-linkage. 
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•	Plated steel material
	
5.	Axles: Minimum ½ in. dia.
•	Plated steel

6.	Bearings: 
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Specifier Notes: Extruded bearing holes in frame provide more axle to
bearing surface area. As a result, bearings will last longer and add to the 
life of the damper. 
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•	Axle bearings shall be synthetic (acetal) sleeve rotating in polished extruded holes in the damper frame. Bronze bearings are optional.

7.	Actuator:
•	Actuator shall be locking manual quadrant.

2.3	SOURCE QUALITY CONTROL

A.	Factory Tests: Factory cycle damper and actuator assemblies to assure proper operation.

PART 3   EXECUTION

3.1	EXAMINATION

A.	Examine areas to receive dampers. Notify the Engineer of conditions that would adversely affect installation or subsequent utilization of dampers. Do not proceed with installation until unsatisfactory conditions are corrected.

3.2	INSTALLATION

A.	Install dampers in accordance with manufacturer’s Installation Instructions.

B.	Dampers must be accessible to allow inspection, adjustment, and replacement of components. The sheet metal contractor shall furnish any access doors in ductwork or plenums required to provide this access. The general contractor shall furnish any access doors required in walls, ceilings, or other general building construction. 

C.	Install dampers square and free from racking. 

D.	Do not compress or stretch the damper frame into the duct or opening.

E.	Handle dampers using the frame or sleeve. Do not lift or move dampers using blades, actuator or jackshaft.

END OF SECTION