Author Archive

How long has static regain been used for ductwork design?

January 31, 2012  |   FAQ's   |     |   9,099 Comments

Static regain has been used since the 1940s and followed the development of the commercial fan and air moving market.  Static regain is very friendly to long term operations but it took a lot of calculating, adjusting sizes and recalculating to get a system balanced on paper. With computer availability in the 1970s, static regain was done with a punch card input system. In the early 1980s, the IBM PCs were used to calculate DOS based ...

What is Equal Friction?

January 31, 2012  |   FAQ's   |     |   19,736 Comments

The Equal Friction design methodology sizes the supply duct system for a constant pressure loss per unit length such as 0.1"wg friction loss per 100 feet of duct. This is a low velocity industry standard. Equal Friction is the most widely used method of sizing lower pressure, lower velocity duct systems. There is no equalization of pressure drops in duct branches unless the system has a symmetrical layout. Dampers are used for balancing.

Does static regain actually save energy?

January 31, 2012  |   FAQ's   |     |   12,013 Comments

Most VAV ductwork systems are sized for a 1% ASHRAE cooling day for 86 hrs/year of peak demand. The average VAV fan system operates at 65-75% capacity for 4000 hours/year and operates at minimum 35% capacity for 2000 hrs/year. With static regain using 30% smaller VAV spiral duct sizes, there is less BHp-Hrs used for part load spiral systems estimated at 5-10% less than rectangular ductwork systems. Actual operating leakage savings using smaller spiral ducts ...


January 31, 2012  |   FAQ's   |     |   17,251 Comments

A local leadership enegry engineer explained that we need to do two important missions. "Stop wasting energy" is required. "Start saving energy" is desired. Static Regain methodology is more efficient with less lbs of supply ductwork, lower acoustic effect and less noise, and part load energy savings which are very important.

1983 5 Story Office building

January 31, 2012  |   Past Projects   |     |   21,482 Comments

1983 5 Story Office: 82,000 SF 5 story with 175 tons DX RTUs using static regain spiral distribution to 145 VAVs. Static regain spiral installed at 18,000 lbs costing $116,700 in place of rectangular MP at 36,500 lbs costing $211,700 saving $95,000 or $1.16 per SF basis 2012$$. Total Job SQFT: 82,000 Total Job Savings: $95,000 or $1.16 per SF basis 2012$$.  

Medical Ambulatory Surgery Center:

January 31, 2012  |   Past Projects   |     |   21,441 Comments

Medical Ambulatory Surgery Center: 20,000 SF Surgery Center with IDPH ambulatory requirements conditioned with static regain distribution and vav pressurization relationships from 115T DX RTUs contracted at $1,195,000 Spiral static regain used 11,200 lbs of spiral costing $72,000 compared to rectangular MP at 23,900 lbs costing $144,400. Total GSF: 20,000 sf Static Regain Savings: $72,400 or $3.62 per SF. Total Job SQFT:20,000 Total Job Savings: $72,400 or $3.62 per SF.

AAA Office HQ, Aurora, IL

January 26, 2012  |   Past Projects   |     |   13,454 Comments

2-Story, 78,000 gsf Hi Tech Office Building using 200T DX RTUs, static regain distribution, Fan Powered Units with DDC Control: $1,450,000 total contract. Spiral static regain used 18,900 lbs at cost of $121,900 compared to rectangular mains at 35,700 lbs costing $207,900 saving Total Job SQFT:  78,000 gsf Total Job Savings: $86,000 or $1.10 per sf. Job Drawings:

Pacific Garden Mission, Chicago, IL

January 26, 2012  |   Past Projects   |     |   15,997 Comments

Pacific Garden Mission, Chicago, IL: 100 panel solar array for pre-heating 8,000 gpd of hot water for domestic use at new mission with glycol, heat x, pumps and controls along with complete Mammoth 200 Ton Penthouse HVAC and static regain distribution for 150,000 sf mission: Total Installed Cost:   $2,900,000 Spiral Static Regain used 36,000 lbs at cost of $236,500 compared to rectangular mains at 59,000 lbs costing $342,500 Total savings:  $106,000 or $0.71 per sf.

Motorola Pine Meadows, Libertyville, IL

January 26, 2012  |   Past Projects   |     |   21,175 Comments

3-story office building, 90,000 SF, with 300 tons DX RTUs, static regain distribution to Data & Tech Center using air column/raised floor pressurization and FPBs, full kitchen and dining system (9000 sf) Total SQFt: 9,000 Total cost installed: $995,000.  Spiral static regain used 16,000 lbs at cost of $104,000 compared to rectangular mains at 34,000 lbs costing $197,000 saving $93,000. Savings of $1.03 cost/SF

Lastest News

  • Why using spiral duct improves duct design – SNIPS article
    April 22, 2019

    In 1948, research by R.G. Huebscher established flow resistance for different shapes of ductwork at equal velocities, which allowed the creation of the duct-sizing calculator or “Ductulator” for picking equivalent sizes of rectangular ducts based on the baseline round duct size. The Ductulator is a shortcut that only works on paper if you reduce the […]

  • 2014 was productive for Optimized Spiral using VariTRANE.
    December 30, 2014

    2014 was productive for Optimized Spiral using VariTRANE. A mechanical contractor in New Jersey used VariTRANE to save $80,000 cost on a 300T fitness center. A strategic partner in Utah used VariTRANE to save $70,000 cost on a 63,000 SF office building. A strategic partner in California used VariTRANE to save $60,000 cost on a […]

    July 27, 2012

    Guaranteed: $20,000 in engineered spiral static regain savings for preparing a redline system design up to 34,000 SF or 100 tons, a value of  $10,000. Included: a one-day static regain seminar at your location before December 14, 2015, Included: 12 months of support consultation by phone and email, a value of  $10,000 a value of    $7,500 a value of    $2,500 Total value […]

  • Trane Strategic Partner Exchange – 6 Real World Examples
    February 25, 2012