What are the risks when foodservice facilities and residential units occupy the same property in mixed-use developments?
The risk associated with mixed-use developments cannot be understated. The complexities from design to execution and delivery of such a project have many inherent risks that if not handled successfully, can create properties that can be difficult to manage or in a worst-case scenario, lead to litigation. With proper planning and execution, virtually all of these risks may be mitigated. The nature of these types of projects requires a system capable of adapting to changes in infrastructure. With building planning and construction timelines covering several years and the useful life of the buildings estimated to be anywhere between 15 and 30 years or more, a system that is put in place should be able to accept or be updated to the latest generation.
The rise of mixed-use developments has created a significant challenge for property developers to have foodservice operations within the same complex or neighboring residential dwellings. While residents want access to these types of amenities, they don’t want to be subjected to nuisance odors and potential fire safety issues associated with foodservice venues.
What comes out of the exhaust of a foodservice operation?
It is important to understand that foodservice operations are effectively production facilities with the associated effluent as a byproduct. In the course of production heat, effluent and volatile organic compounds (VOCs) are produced. These are typically exhausted to the atmosphere and carry condensable grease and odor with them. With residential properties proximate to these establishments, it creates a condition that lends itself to odor and/or smoke complaints. Fire safety is another issue that must be addressed. Regular maintenance of the system components and ductwork is critical.
Most of the odor from cooking is contained in the VOCs. The VOCs are in vapor form. This is an important consideration because it cannot be removed by mechanical or filtration means. Grease particulate can be removed by mechanical filtration at the hood level while grease and smoke (with the appropriate level of filtration) can be removed at the pollution control unit (also called a “scrubber”) based on the efficiency of the unit.
There is a variety of filtration methods that can be deployed at both the source and discharge areas for applications that are considered Odor Critical.
Factors to take into consideration for kitchen ventilation in mixed-use developments
When assessing the design and systems to be used, the following are some of the factors to be considered:
- Infrastructure flexibility
- Allowance for future foodservice operations
- Independent operation of the foodservice tenants
- Minimizing duct routing and determining exhaust discharge
- Allowance for pollution control devices and odor critical systems
- Monitoring of systems
- Enforcement of maintenance
- Allowance for future foodservice operations
- Filtration needs
- Number and type of foodservice operations
- Cooking processes from bakery to a steakhouse
- Operational hours
- Estimated loading and maintenance cycles
- Odor Mitigation
- Area of discharge
- Best available technology
- Odor monitoring capabilities
- Avoidance of residential complaints
- Fire Risk
- Monitoring of the affected grease duct
- Code compliance for ductwork
- Tenant and Developer responsibilities
- Well defined responsibility scope
- Established tenant criteria
If the foodservice tenant spaces are defined and the exhaust and make-up air systems can be isolated within the perspective tenant space, then it is a pretty straightforward equation. Assurance must be provided that allows for the pollution control unit (larger physical footprint) and access for maintenance.
If there are multiple foodservice tenant spaces being designed, it is generally practical to combine the exhaust systems into a “manifold configuration”. A manifold duct system allows for a central Scrubber to serve multiple tenant spaces.
There are systems and controls available that can easily manage multiple tenant systems on common ducts and have them operate independently of each other.
At the hood level, the primary filtration method is what is commonly referred to as “grease filters”. They are visible within the exhaust hood and are typically removed daily for cleaning. This would be the tenant responsibility. The efficiency of these filters varies widely and there is a limit to their effectiveness. Published efficiency for a given grease extractor is readily available.
Another technology that is often deployed in mixed-use development applications is Ultraviolet light in the exhaust hood. UV-C is not a filtration technology, but it converts grease particulate at the molecular level to an inert powder.
What is available to remove grease and odors?
As far as Pollution Control Units (PCU’s) are concerned, there are paper filter units and Electrostatic Precipitators as the filtration methods for Scrubbers. The effectiveness of the filtration method is a function of the filter rating.
Media filter units are lower first cost, but higher maintenance cost as the filters are disposable and need to be replaced when full. Most systems have filter monitoring capability to indicate when the filters need to be changed — accounted for in the operational budget.
ESPs are higher first cost, but lower maintenance cost. They remove particulate by charging the grease particles, and as the particles travel between parallel, charged, and grounded oppositely charged plates, they are repelled to the grounded plates and drain off.
As previously stated, odor from cooking processes is the primary complaint of residential tenants residing in mixed-use developments. Although appealing in limited exposure, chronic odor migrating to residential tenants has led to the devaluing of properties and litigation to mitigate odor generation.
There are several odor abatement systems and some very promising new technologies on the market. These technologies run the gamut from odor masking sprays to UV/Carbon with odor sensing “noses” that monitor the carbon life and effectiveness.
UV/Carbon Panels, The most effective combination of odor mitigation technology available. The UV bulbs generate ozone, which acts on the VOC’s and the carbon adsorbs them. New technology now uses an odor sensor or “nose” that can detect the efficiency of the odor abatement and the life of the carbon. These types of systems should be considered for Odor Critical applications, where residential tenants will be exposed to foodservice tenant exhaust systems.
Putting it all together
At its core, the well-defined scope of responsibility is the key to a successful mixed-use development project. Although it may appear daunting in a fluid, fast-moving project, it can be done. The following is an example of a comprehensive scope that is part of the construction documents and tenant lease documents.
With a properly planned design with the appropriate technology in place, you can be assured that all of the challenges of mixed-use retail and residential properties are addressed.
For a more comprehensive guide on scope responsibility and design details, please feel free to download our whitepaper on the subject.
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