The Hysen Group is an international consulting firm headquartered in
Northville, MI. It provides concept development and design, engineering
and management services to a variety of foodservice segments.
You can't manage what you don't measure. “The first issue on the table when you consider onsite kitchens is that we typically do not measure the steam, the electricity, the water or natural gas that goes into running a college or hospital or other onsite kitchen. People want to do the right thing but have no way to know if they are doing the right thing.
“In contrast, if you go to a typical shopping mall, every shop is separately metered. So you are starting off with a premise that on its face is not manageable. Many proposals can be more easily justified if you use systems for evaluationg return on investment comparisons of how much energy is actually used by existing equipment vs. replacement equipment.”
Look hard at refrigeration. “Refrigerators and freezers are one of the biggest energy using equipment categories. We try to design freezers so they are never entered directly from an ambient temperature room. Use your 35°F walk-in cooler as a vestibule from which to enter your freezer compartment.
“On new installations, a properly recessed floor should be installed; if not, you will in short order have water infiltration in the insulated wall and floor panels. That dramatically reduces their insulation value and causes the compressor to run harder and longer. A payback on the additional expense is typically 2-4 years for an installation that will have a 20 year or more life.
“A good maintenance program to keep evaporator and condenser coils clean is essential and should be part of a regular maintenance checklist. Some companies now put automatic coil cleaning systems on their units and some operators may find these worth considering.”
Balance specs with practicality. “We often install 1-in. plexiglass/acrylic doors with pneumatic closers on walk-in refrigerators rather than less expensive, 4-in. insulated doors. Though plexiglass does not have the R-value (a measure of insulation) of an insulated door, the fact that employees feel comfortable letting the door close while they're inside means they are less likely to prop it open. Cleanliness and sanitation are also enhanced since managers can easily check the state of the cooler as they walk by.
“Similar issues exist with cooking equipment. Some appliances, like quick-bake ovens, are not especially energy efficient in a theoretical sense but can be very efficient in an operational sense because dwell times are so short.”
Bigger is often better. “Generally, one bigger unit will be more efficient than multiple smaller units. This goes for ice makers, water heaters, steam production, etc. In new construction, we believe direct steam from a main building boiler is a better choice in many cases than other options. It may require more attention to maintenance schedules, but it usually pays off over time.
“There are exceptions to ‘bigger is better’. In refrigeration, split compressor systems are a good idea. Even though they're slightly less efficient, they provide redundancy in case one compressor goes down. That gives you breathing room to get the repair done without losing the contents of the freezer.”
Watch how production lines are ventilated. “It is common to find that mechanical engineers have looked at tray make-up areas where hot food is plated and have installed two or three airconditioning diffusers to blow cool air directly on those areas. It may be technically appropriate because of the heat being produced, but it dumps cold air directly on hot food you are trying to keep warm. We like to see such supply diffusers nearby, but not where they blow directly on the prep and holding areas.”
Lighting technology is improving. “Motion detectors are very useful in refrigerators, store rooms and bathrooms. We are doing a lot with LEDs today in walk-ins and display cases. LEDs not only reduce power consumption but also reduce heat gain significantly, lowering the airconditioning load. The color temperature of these lamps is improving when it comes to their use in merchandising applications and will continue to get better.”