Upon reading the new Chicago mechanical code sections dealing with grease ducts and hoods, we were immediately struck by some serious omissions. While Chicago’s Mayor Daley had wished to adopt model ICC Code language, Chicago’s new mechanical code language fails to include certain elements critical to energy conservation.

City code writers did not include model code language developed through years of extensive research and testing by UL, the University of Minnesota, ASHRAE and both private and industry test labs.

By not following the mayor’s instructions, Chicago code writers created a new mechanical code that is out of step with the commercial kitchen ventilation (CKV) industry.

LISTED HOODS

By leaving out any reference to listed hoods, UL listed hoods are not available as an option. Listed hoods are the main choice of savvy CKV designers, building owners and operators for their energy savings.

1. The new city mechanical code contains no reference to the use of listed hoods. The Q formulas given in the new code reflect the use of outdated and oversized methods of dealing with kitchen ventilation. These formulas are only used with non-listed commercial kitchen hoods.

   A. Listed hoods are those that are certified by UL and others to operate at significantly lower air quantities to that of the old Q or square foot formulas. This listed hood option reflects in energy savings and operating costs to the building owner or operator.

   B. Lower air quantities are available to designers using listed hoods and allow both smaller ducts and duct shafts, a major cost savings to owners and developers.

   C. The elimination of listed hoods quietly accepts the fact that poorly constructed hoods may be acceptable to city inspectors. Safety may often be compromised since many are fabricated substandard. These hoods are built only for price and may not follow nationally recognized standards for safety. These compromises can be subtle and are often missed by city inspectors who are unable to recognize the differences.

   D. Item C will be welcomed by general contractors who often regard kitchen hoods as a place to hide higher profit by ignoring well designed hoods in favor of inexpensive built for a price models.

LOWER AIR VELOCITY

A second instance of ignoring changing codes and standards is the failure to include the use of new lower air velocity industry research, University of Minnesota research project number 1033-RP, funded by ASHRAE.

1. The limiting high air duct velocity of 1500 to 2100 FPM (feet per minute) through the grease duct is retained in the Chicago July 28, 2004 Mechanical Code. It applies to non-listed and listed hoods. See item 2 and the IMPORTANT DISTINCTION box below.
    
2. The current NFPA Standard No. 96-2004 (National Fire Protection Standard) has lowered the base figure to 500 FPM. The ICC in their International Mechanical Code has also adopted this lower base air velocity. ICC Proposal M45-03/04 was approved in September 2003. The revision appears in the 2004 Supplement. It will appear in the next published hard cover edition in 2006.

 ENERGY CONSERVATION

Energy conservation is the primary consideration. Testing sponsored by ASHRAE at the University of Minnesota has proven the practicality of this new reduced base figure, allowing the lower 500 FPM air velocity to be adopted using variable speed technology. The benefits are as follows:

A. Lower energy costs for the lifetime of a given installation are immediately available to the owners of buildings for as long as they are in use. Estimates of savings vary from $1.00 to 3.00 per cubic foot of annual air costs. That includes the cost of heating and air conditioning a building via make-up air to replace the contaminated air exhausted by the hood(s).

B. Variable speed fan and control technology becomes the key to using fans that automatically adjust to the cooking effluent load at any given time, allowing further annual air operating costs.

C. Duct systems and building duct shafts using listed hoods are generally smaller reducing the cost of construction to owners and keeping a lid on ever rising per square foot costs.

D. KEY POINT -The lower FPM air threshold provides the allowance of potentially using existing CKV duct systems and building air shafts when remodeling - a major consideration with as many restaurants as Chicago has.

Much of the progress made by CKV industry members over the last several years goes unrecognized by these omissions in the new Chicago Mechanical Code.

WHY?

We have learned that there may be some relief being developed in the way of an addendum or revisions. However, at this time we are unaware of the details. UP YOUR STACK™ has offered to assist the committee in correcting these issues. It remains for the City Council to vote on the changes. A vote is not anticipated until some time in 2005.

There is no indication that the lower air velocity allowing variable speed fan technology is being considered at this time. We encourage the committee to recognize and add this technology and code language.

What happens in the interim? Chicago officials maintain they can only respond to what is written in the code. Exactly what does that mean?

HIGHER CONSTRUCTION & ENERGY COSTS

The City Council passed the new code on July 9, 2004. That means that since July 28, 2004, when the new Chicago Municipal Building Code was issued, listed hoods are neither acceptable, nor recognized in the city. It may be confusing enough for private restaurant operators who are accustomed to co-existing with the cities code inspectors and code language, but chains are another story entirely.

National chains, and Chicago has them all, rely on good choices for their equipment and design. When the choice to use a listed CKV hood is taken away without any apparent reason, chains are forced to deal with many decisions. Greater CFM needs create the primary reason resulting in larger exhaust ducts, larger exhaust fans, larger heating and air conditioning systems. These choices result in higher construction costs and higher energy costs for the life of the system.

We believe that creates an unwelcome sign by the City of Chicago.

When will this situation be rectified by the City Council? The council holds the power to make the changes and include listed hoods. The key question becomes when?

WHAT HAPPENS NOW?

What happens in the interim? Architects, mechanical engineers, developers, owners, designers, consultants and suppliers are left with a decision. How should they respond to the code as written?

Should they redesign at higher costs to all?

Should they delay designs and construction pending City Council action?

ACTION CALL

Clearly neither of the above becomes a good option. We suggest writing to the mayor at his office. If enough concern is shown, we hope the city will respond in a timely manner. The mayor and related department heads can be reached at the following address.

Mayor Richard J. Daley
Office of the Mayor
121 N. LaSalle St. Room 507
Chicago , IL 60602

Cc:      Mr. Fabio Grego, Department of Construction and Permits
           Mr. Stan Kaderbeck, Building Commissioner
           Mr. Tom Domain, Ventilation Section Chief

The Chairman, for the Mechanical Code Working Group coordinating city efforts is:

Mr. Anthony B. McGuire, P.E.
President
McGuire Engineers
300 S. Riverside Plaza
Chicago , IL 60606

The opinions expressed here are those of UP YOUR STACK™ and are meant to educate all who deal with commercial kitchen ventilation in the City of Chicago and to make them aware of the new Chicago Mechanical code.