One of the main points in Steve Melink’s article titled “Commissioning Kitchens” is that the mechanical contractor is normally responsible for T & B, or testing and balancing of the HVAC systems. Think about it this way, it means that the mechanical contractor oversees and attests to his own work. What is his incentive to spend a lot of time and effort to find or report problems involving his own work?

It is for that very reason, that UP YOUR STACK™ and other professional members of ASHRAE’s Technical Committee for Kitchen Ventilation have been recommending commissioning by an independent or third party that reports directly to the owner.

Quoting from Steve’s article, “By reporting directly to the building owner, the T&B firm is empowered to ensure that the owner receives the HVAC system for which he paid. When a T&B technician finds a problem with the design, equipment or installation, he can communicate his findings without undue pressure from the engineer, contractor or manufacturer.”

Steve points out in his article that multi-unit operators have much to gain from using a single source T&B firm. The consistency of having one firm monitor new installations builds a database of how well the design works over a number of locations. It also readily points out when a new location is not checking out properly. A design can be modified and fine tuned to provide for use of the best fans, the best duct configuration as well as other accessories.

One point that should be stressed is that in too many instances, the local HVAC contractor or his T&B firm is testing kitchen exhaust systems without the equipment being heated up to normal cooking conditions. Without the thermal plume in place from the hot equipment, there is no reality to testing at that point. A thermal plume of hot air coming off the top of the cooking equipment, teamed up with the exhaust fan and the hood is what makes a kitchen hood system work.

A local Chicago area mechanical designer and fellow ASHRAE member called us this week to discuss a problem project. One of the questions we asked was the cooking equipment turned on and hot when the T&B was performed? Checking back, he found out that the cooking equipment had not even been delivered. Yet, the contractor performed a T&B and now the local chain operator is complaining of problems. The T&B will now be performed for a second time, this time with all the equipment in place and operating.

Steve’s article is much more in depth and we recommend that you follow the ASHRAE link in the short description of this newsletter.