Wendes HVAC Estimating Blog

Wendes Labor Estimating Background

Posted by joseph damelio on Thu, Mar 25, 2010

HVAC Estimaitng Labor Manual

Wendes  Systems, Inc. was founded by Herbert C. Wendes PE who authored an estimating instructional manual designed to assist HVAC Sheet Metal Estimators in the methodology for preparing thorough and accurate HVAC sheet metal labor and material cost estimates.The manual contained a logical step-by-step approach for producing HVAC sheet metal estimates.The detailed unit labor cost data contained in his manual was derived from more than twenty five years of labor studies conducted by Herbert C.Wendes during his career in the HVAC industry. The studies included the various steps in the process for manufacturing and installing HVAC sheet metal ductwork in commercial buildings.Herbert C. Wendes was invited by trade associations and independent companies to conduct workshops throughout North America  instructing estimators in the principles detailed in the instructional manual.

 During 1980 many of the labor calculations and formulas contained in the instructional manual were converted to program language for use with a hand calculator. With the introduction of the IBM XT computer the mathematical formulas for producing labor and material cost were then programed for the DOS operating system and have become more detailed and sophisticated with advancements in computer technology.     

Topics: HVAC Sheet Metal Estimating, Background On Wendes Estimaitng

We Are Often Asked.....What Are HVAC Systems?

Posted by joseph damelio on Wed, Mar 24, 2010

HVACHVAC refers to an air system for heating and cooling in a commercial or residential building. The various components of HVAC systems include a heating furnace, a blower motor assembly, an evaporative coil, a compressor and compressor coil, and  the associated air ducts to distribute air within a building.


HVAC systems are designed to control humidity and circulate air in a building. There are various  types of HVAC systems and equipment used in commercial and residential applications. Some factors to be considerered in the design of HVAC systems include the flow rate and air pressure for the ventilation system. The air velocity and air pressure in a duct system is regulated by the duct size, duct type, fan size, fan velocity,grills, registers and air flow dampers that control air flow in the HVAC ventilation system.
HVAC Sheet Metal Estimating or HVAC Ductwork Estimating genarally refers to the material and labor cost estimates required to construct a heating and cooling ventilating system. All aspects of material and labor cost are itemized to determine the total cost estimate for the HVAC ventilating system. A comprehensive bill of materials based on specific design criteria and specifications for the HVAC system are produced with the associated labor cost for manufacturing and installing a system in a building.  


Topics: HVAC Sheet Metal Estimating, Cost Estimating, Labor Estimating