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REFRIGERATED food storage design
Spencer Engineers,
Inc. (SEI) is the AE of
Record and Gerald Spencer, P.E. is the MEP Engineer of Record for many cold storage units in grocery stores and restaurants. SEI is also the AE
of record for the refrigeration system replacement at the Fort Polk Refrigerated
Warehouse Building 4366.
GROCERY STORE AIR
CONDITIONING AND REFRIGERATION:
Refrigeration systems used in food retailing today are changing to meet the
requirements for energy efficiency and environmental concerns. New
installations are using new HFC refrigerant blends to replace the older CFC
refrigerants -- R- 12 (medium temperature) and R-502(low temperature). New
medium temperature systems are using R-134a, and low temperature systems are
using blends of two or more of the following: R-134a, R-125, R143a, and R-32.
The recommended blends available for low temperature at this time include three
ternary blends and one binary blend -- R-407A, R-47013, R-507, and R-404A. A
compromise is to use R-22 for all temperatures, understanding that R-22 will be
banned in 10 years. R-22 would not be recommended for new, but where it is
already existing in a good system, it should be considered as a part of a phase
out program.
1.
Because the condensing temperatures of these new blends are typically
higher than that of the older R-502 for air cooled systems, design pressures of
system components and vessels has to be rated for 4OO psig in lieu of the 350
psig of R-502 systems. For this reason, water cooled condensing becomes more
economically feasible. This opens up opportunities to integrate a common
condensing water loop for air conditioning and refrigeration. If the heat pump
technology is used on the air conditioning, there are tremendous opportunities
for complementary performance when the systems are linked in this manner. This
is an emerging concept that has great potential.
2. For conversions of existing systems, the solutions are not easy. There
is no simple inexpensive process that will convert existing CFC and HCFC to the
long-term alternatives. Oil selection alone is a big problem, pipe sizing often
is inadequate. The number of system types, the ages of equipment, operating
efficiency, and installation quality all vary.
3.
Air conditioning in a food retailing environment is critical. It is
imperative that humidity be controlled. Without direct humidity control,
refrigeration systems will cool the store, causing the air conditioning back
off, causing humidity to zoom out of control. For every IO% rise in relative
humidity within the store, the load on cases increases 5 0%. Additionally, coil
frosting increases significantly, requiring defrost cycles, which are
devastating to energy costs.
4.
To solve the humidity problem, there are several solutions'.
5
Use standard vapor compression systems with reheat. Reheat may be gas,
electric, or refrigeration reclaim. This will work in dry climates.
6.
Use specialized vapor compression equipment with high latent coils,
by-pass air arrangements, and reheat. Reheat may be gas, electric, or
refrigeration reclaim. These systems are the majority of that employed in
quality installations in humid climates.
7.
Desiccant dehumidification combined with vapor compression cooling.
These systems provide desiccant dehumidified air into cold isles and around
cases. These systems do an excellent job and are energy efficient, but there is
a high first cost.
8.
Water cooled heat pumps. May use a common condenser water loop with
refrigeration systems. Cooling, outside air pre-treating, and reheat, are all
independently controlled and use the condenser water loop.
9.
The following is a list of refrigeration projects where SDJ&S was the
Refrigeration System EOR.
9.1.
U S Army - Fort Polk - Bldg 4366 Central Cold Storage Facility - Replace
All Refrigeration Systems 350 tons - Miscellaneous Repairs - $1,796,000
9.2.
M D Anderson Cancer Center - Smith Research Building - Add Cold Storage
Rooms in various research labs.
9.3. USPS Central Mail Facility - Repair Two 500 ton Centrifugal Chillers
9.4. Safeway Grocery Stores No. 405, 406, & 409 - Houston, Texas
9.5.
Fort Hood, Texas - Three Post Exchange Buildings with Refrigerated
Vegetable Storage, Dairy Product Storage, and Frozen Food Freezer.
9.6. Lackland AFB - Enlisted Men's Dining Facility - Refrigerated Vegetable
Storage, Dairy Product Storage, and Frozen Food Freezer.
9.7. TRADE WINDS MOTOR HOTEL AND ADDITION - WICHITA FALLS, TEXAS - Motel with
full restaurant plus refrigerated food storage.
9.8. HOLIDAY INN PARK 10 - 19 FLOOR - 350 ROOMS - HOUSTON, TEXAS - MEP
Consultant - This is a high rise hotel with restaurants, kitchen plus
refrigerated food storage.
9.9. L'HOTEL SOFITEL - 8 FLOORS - 375 ROOMS - HOUSTON, TEXAS - MEP Consultant
- This is a high rise hotel with three separate restaurants, meeting rooms,
indoor swimming pool. laundry and two full kitchens plus refrigerated food
storage.
9.10. ALBERT PICK HOTEL 250 ROOMS - 10 FLOORS MEMPHIS, TENNESSEE - MEP
Consultant - We designed the HVAC, Electrical and Plumbing systems for this
facility with a kitchen plus refrigerated food storage.
9.11. EXECUTIVE INN 150 ROOMS - 4 FLOORS - MEP Consultant - We designed the
HVAC, Electrical and Plumbing systems for this facility with restaurant plus
refrigerated food storage.
9.12. Exxon, USA - Production Research Facility Cafeteria - - Refrigerated
Vegetable Storage, Dairy Product Storage, and Frozen Food Freezer.
9.13. STEPHENVILLE HIGH SCHOOL -
STEPHENVILLE, Texas - A one level (9th-12th grade) school that included,
Kitchen and refrigerated food storage, etc. for 1000 students. We designed the
MEP for this project.
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