ASHRAE Pipe Sizing Requirements Are Changing – System Syzer Makes It Easy!

Bell & Gossett’s System Syzer does all the piping calculations necessary to meet ASHRAE 90.1 and 189.1 requirements. JMP is committed to getting all our customers up-to-speed on ASHRAE 90.1 – 2010. We’ve already covered some of these topics in previous blogs, including changes to pressure booster design.  Today’s blog focuses on the portions of 90.1 - 2010 that dramatically impact the selection of pumps and associated piping.

According to ASHRAE 90.1 – 2010, engineers must determine the pump differential pressure (head) for all newly installed commercial hydronic systems.  Specifically, engineers must calculate and document the expected pressure drop through each device and pipe segment in the critical circuit at design conditions. 

Furthermore, chilled water and condenser water piping cannot exceed specific sizes outlined in the standard,based on factors including whether the system is variable or constant speed, annual hours of operation, and flow rate. (See Table 1)  This is, of course, to encourage engineers to design systems for operational efficiency rather than lowest installed cost.

There are additional challenges for those attempting to meet ASHRAE 189.1 Standard for Design of High-Performance Green Buildings.  Some entities, including the Army Corps of Engineers, have already adopted this high performance standard. 

Included in Standard 189.1 is the requirement that all condensate from air conditioning units with a capacity greater than 65,000 btu/h (19kW) and condensate from steam systems shall be recovered for re-use purposes such as irrigation.  This, too, indirectly impacts the sizing and selection of some fluid handling equipment.  If a condensate unit is chosen to collect the water, then the anticipated condensate must be determined and the collection device sized accordingly.  Of course, the same pipe sizing requirements of ASHRARE 90.1 discussed above are also included in ASHRAE 189.1.


B&G System Syzer Is ASHRAE 90.1 And 189.1 Compliant

It may seem as though ASHRAE just made engineers’ jobs more difficult but JMP has good news for those who haven’t the time or the practice to perform the piping calculations required to meet ASHARE 90.1.  Bell & Gossett’s Version 4 System Syzer® program, available as a free download, does all the work for you!  It even includes psychometric data that allows engineers to appropriately size condensation collection equipment to meet 189.1.

 To meet the requirements of 90.1, engineers need only input a few known values and the program does all the sizing to meet the standards.  A downloadable manual is also available on “Hydronic System Design with Bell & Gossett System Syzer®”.   If you find you need any further assistance with the program, don’t hesitate to call on your JMP rep.  We know the system well and can get you up to speed quickly.

 Here are some important features to the ASHRAE Compliant System Syzer Version 4 Program:

-       ASHRAE 90.1 and 189.1 Compliant

-       Spanish Language Option

-       Includes English & Metric Units of Measure

-       Suitable for PVC Pipe applications

-       Handles fluids other than water

-       Includes a greater range of pipe sizes

-       Incorporates Circuit Setter wheel


-       iPad and Iphone versions availableWhat the earliest version of the System Syzer looked like!

A Little System Syzer Trivia

For those who are true technological trivia buffs, you may be interested to know that it was the famed Bell & Gossett Engineer, Gil Carlson,who invented the original System Syzer, a handheld cardboard version created to help design and analyze hydronic systems.  This was, of course, several years before the invention of handheld calculators.  Since that time, hundreds of thousands of System Syzers in its various versions have been distributed to engineers and tradesmen.  Needless to say, the sleek, intuitive Version 4 we speak of here is truly the product of decades of hydronic expertise and technological enhancement. But the original concept was indeed the creation of one of the greatest hydronic engineering minds of modern times.  It is not surprising that Gil Carson, who passed away in 1994, is known as the “Father of Modern Hydronics”.

If you want to see your states current adoption status visit