 |
 |
BUYING A WALK IN COOLER OR FREEZER
When making a decision on which walk in cooler or
freezer to buy there are many things that must be
considered. In the following we hope to go through all
these considerations and provide you with the
information you need to make an informed decision.
WHAT IS IMPORTANT TO YOU:
Most walk in coolers and freezers manufactured today are
constructed of foam insulation bonded between two sheets
of sheet metal and come equipped with cam locking
devices to allow the assembly of the panelized walk in
on site.
There are a few companies that also provide a completely
assembled unit that is delivered on a truck and dropped
off at your location. These are usually for outside the
building installations. Refrigeration systems are also
usually provided in several types of configurations
along with the walk-ins. These systems will be explained
later.
All walk-ins coolers and freezers are designed to keep
the products inside cold.
When considering the purchase of a walk in you must
consider what is important to you. If a low up front
price is most important due to budgetary consideration,
then the up front price may be a very important
consideration in buying your walk-in. (Usually lower
costing walk-ins have a lower up front cost but when
considering the higher energy expenses they may cost
more over the life of the unit). If overall cost of the
walk in over the life of the unit is important then a
little higher up front cost but lower energy use and
maintenance cost over the life of the unit may be the
way to go. Either way you go, quality workmanship and
materials are a must when buying a walk in.
Make you decision on your needs and not what someone is
trying to sell you. After all customers needs are not
the same, one product does not fit all.
MATERIALS:
INSULATION MATERIALS:
There are three types of insulation used in walk-ins
today; expanded polystyrene insulation, polyurethane
insulation and extruded polystyrene insulation. Each
insulation is constructed of gas filled cellular plastic
foam and each brings with it different benefits to the
customer.
1. Expanded Polystyrene - This insulation is the same
type of insulation used in Styrofoam cups. It has been a
reliable insulation material that has a lower up front
cost but also has a lower initial 90 day aged R-value
(The higher the R-value the more resistance to heat flow
thus less energy used) than the other two insulating
foams. Its R-value is 4.75 per inch or R-19 for a
four-inch panel. It has a moderate resistance to
moisture penetration, which lowers the insulation's
R-value and has moderate ability to keep its R-value
throughout the years. It has been very successfully used
in the manufacturer of quality walk in coolers and, in
higher densities and thickness freezers.
2. Polyurethane - Polyurethane is among many other
things used as packaging foam and in the construction of
walk through outside residential and commercial doors.
It has a high 90 day aged R-value of R-24 but is less
capable of moisture resistance and R-value retention. It
can loose as much as 75% of its R-value to as low as
(R-6) over the life of the product. It is a good
insulation for manufacturing products that include
intricate parts that need to be bonded together. It has
been used a long time in the manufacture of walk-in
coolers and freezers.
3. Extruded Polystyrene - This insulation is used in
insulating underground concrete foundations and floors.
It has a high 90 day aged R-value (R-20) and has a great
moisture resistance and ability to retain around 75% of
its R-value or (r-15) over the life of the product. It
has great structural strength of up to 4 times that of
polyurethane and expanded polystyrene. It is a little
higher than expanded polystyrene insulation but about
the same as polyurethane insulation. It is better than
expanded polystyrene and polyurethane insulation if
overall performance is considered. It is an insulation
that will continue to pay dividends in energy savings
for as long as you own the walk-in.
METAL SKINS:
Walk-ins come with several different types of skins
depending on what the customer desires. Each of these
skins provides different benefits to the customer.
1. G 90 Galvanized - This economical material is
probably the most popular skin used in walk-in coolers
and freezers. The G90 depicts the type of galvanizing
with G60 having less resistance to corrosion than G90.
G90 is the minimum needed in producing a walk-in cooler
or freezer. Its advantages are that it is reasonably
priced, strong and more dent resistant. Its disadvantage
is that it can develop what they call white rust if it
is not handled correctly in installation and if caustic
cleaners are used. Once white rust has formed it can
turn into red rust if not treated. G90 can be stucco
embossed making it even stronger and also give it the
aluminum embossed look that is sometimes desired in the
market. G90 is usually provided in 26-gauge minimum in
thickness for walls and ceilings and a 16-20 gauge
thickness for floors. Note that G90 galvanized floors
are not approved for manufacture by the National
Sanitation Foundation for food service applications.
Galvanized floors however can be used if quarry tile is
installed over the floor before use.
2. Aluminum - Aluminum as a raw material is more
sensitive to price fluctuations. It is very resistant to
corrosion except for salt spray and is not as strong as
other metals and can dent very easily. Aluminum is
usually provided in 40-60 mill thickness for walls and
ceilings and 100-120 mill thickness for floors.
Sometimes aluminum floors are 1/8th-inch thick and
diamond tread-plate embossed to add further strength.
Most of the time aluminum for walls and ceilings are
stucco embossed to increase their strength.
3. Galvalume - Galvalume is steel coated with
combination of aluminum and galvanizing material. It has
the strength of steel but is twelve times more corrosion
resistant than galvanized. It is usually provided in a
26-gauge minimum thickness. It has a gray look that is
usually embossed to make it look more appealing.
However, is more expensive than both aluminum and G90
galvanized. If up front cost is important this metal may
not be desired.
4. Painted G90 Galvanized - Painted galvanized is more
expensive than Galvalume but is more resistant to
corrosion and has the benefit of providing a choice in
color for customers who want the painted look. NSF must
approve the paint system used for the walk-in to be NSF
approved.
5. Stainless Steel - Stainless steel is the most
expensive of all metal skins normally used in walk-in
construction. It is the strongest and least corrosive of
all the metals and usually comes in 24-gauge thickness.
It comes in different polishes such as brushed and
polished. Most walk-in coolers come with the brushed
look to reduce the visibility of scratches.
Deciding on the skin you desire may once again depend on
whether up front or long term savings are important.
REFRIGERATION SYSTEMS:
Refrigeration systems consist of a condensing unit and
an evaporation coil. The condensing unit is located
outside the walk-in and the evaporator is located inside
the walk-in. The compressor compresses gas to a liquid.
It is then pumped through the condensing unit coil while
a fan blows outside air through the coil. Gas is
condensed to a liquid and is then pumped through a small
copper pipe into the walk-in to the evaporator coil.
There, through the expansion valve located in the
evaporator coil the liquid is allowed to expand back
into a gas. The expansion of the liquid to a gas causes
a rapid chilling of the evaporator coil. Since heat
always flows toward cold, inside, the walk-in, air is
blown across the evaporation coil to let the coil absorb
heat from inside the walk-in. The gas is then allowed to
exit the walk-in through a larger copper pipe to the
condensing unit where it is once again compressed and
cooled to a liquid state and returned to the evaporator
coil inside the walk-in. There the cycle is started
over.
Refrigeration systems like walk-ins can be purchased
with lower up front cost but higher operating cost or
higher up front cost but lower operating cost. This
decision is up to you and what you deem most important.
All of these systems come in different shapes and sizes,
which will affect how much you pay up front and how it
performs. In the following you will find the different
type of systems and their pros and cons.
1. Remote Systems - Remote systems are the least
expensive systems to purchase. They consist of a
condensing unit, evaporator unit and misc. parts such as
expansion valve, site glass, dryer, pump down solenoid
thermostat and on freezers a timer and drain heater to
install the system. They require the use of licensed
refrigeration installer since they are pumped down and
charged with refrigerant gas on location. The installer
will also charge for any other parts needed for the
install such as copper pipe, pipe insulation, connectors
and electrical. They are less expensive systems to buy
with the walk-in but may cost more over all depending on
what the going hourly rate is with the installer and the
cost of the parts he provides. They also provide an
advantage by allowing the condensing unit to be located
outside the building. There the condensing unit can dump
its heat without adding extra heat to the building and
air conditioning systems.
2. Pre-assembled Remote Systems - Pre-assembled Remote
Systems are the same as Remote Systems except all the
parts are shipped installed on either the condensing
unit or the evaporator coil. Pre-assembled Remote
Pre-charged systems come with the condensing unit, the
evaporator coil and line set (copper pipes that connect
the two units) charged with refrigeration gas. A
licensed refrigeration technician will be needed to
install the refrigeration system. These systems may or
may not be less expensive depending on the cost of the
system, the refrigeration service and electronics
service charges.
3. Standard Top Mount - Top Mount Systems are
self-contained refrigeration systems. They come with all
parts, copper lines and refrigeration gases completely
installed. A licensed refrigeration technician will be
needed to install the refrigeration system. The only
downside to these units is that the evaporator hangs
down inside the walk-in taking up shelf space and head
room in small walk-ins. Some units come with low profile
coils that help but do not eliminate this problem.
4. Side Mount Refrigeration System - Side Mount
Refrigeration Systems are the same as Top Mount
Refrigeration Systems except they are installed on one
of the wall panels with bolts that go through the
refrigeration plug and wall panel and are attached with
nuts on the inside of the walk in. They also require
that a condensation drain hose be connected to a drain
nearby. A licensed refrigeration technician will be
needed to install the refrigeration system. One downside
is that you loose shelf space where the evaporation unit
extends inside the walk in.
5. Saddle Mount Refrigeration System - Saddle Mount
Refrigeration Systems come completely pre-assembled on a
bracket that is designed to be mounted over the top of
one of the wall panels. These systems must be installed
on a panel with slots cut in the top to allow the
bracket to go through the wall. These systems are hung
over the wall before the installation of the roof. A
licensed refrigeration technician will be needed to
install the refrigeration system. These units also have
the evaporator coil that hangs from the top of the panel
but it is more toward the top and doesn't interfere with
the shelving as much as a side-mount unit.
6. Penthouse Refrigeration System - Penthouse
Refrigeration Systems are like Standard Top Mount
Systems except they do not have an evaporator coil
sticking down inside the walk-in. The air inside the
walk-in is drawn up through the evaporator coil located
with the condensing unit on top of the walk-in to be
cooled. These systems sometimes seem higher in up front
cost but when all things are considered including the
fact that they are factory assembled and don't take up
space in the walk-in it is less expensive in the long
run.
7. Roll Up Refrigeration System - Roll up Refrigeration
Systems are a lot like Penthouse Refrigeration Systems
except they are rolled up to an opening in the side of
the walk-in and attached to the unit. One difference is
that even though the evaporator coil is located outside
the unit it takes up shelf space inside the walk-in
because shelving should not be installed in front of the
unit. A licensed refrigeration technician will be needed
to install the refrigeration system.
Now that you know all about these units don't let it be
confusing. To simplify the selection of refrigeration
system, first decide whether allowing the condensing
unit to dump heat into the building is unacceptable. If
it is then a remote unit is the correct choice. Whether
it is pre-assembled pre-charged should be decided by
evaluating the difference in cost of having it done in
the field or at the walk-in plant.
If dumping the heat inside the building is not a concern
then choosing a self contained side mount or top mount
refrigeration system verses a penthouse or rollup
refrigeration unit should be decided by how important
the space in the walk-in is to you. If space is
important then a penthouse unit is the choice. If space
is not a big consideration then side-mount, top mount or
rollup unit may be the choice.
Whatever the refrigeation system you chose it is
important to check the efficiency of the unit and the
manufacturer's warranty to make your final choice.
OUTDOOR APPLICATIONS:
Cooler and Freezers refrigeration system that are
installed outdoors requires a winter kit. This kit
provide a compressor cover, a crank case heater to keep
the oil in the compressor warm so the compressor will
operation properly in the cold weather, and a fan cycle
control will keep the head pressure at the proper
levels.
Outdoor Coolers and Freezer need to have rain roof
installed to prevent water from leaking into the box. A
rain roof can be of a single membrane polyester
polyvinyl, chloride roof system with connectors and a
drip cap for the door, or it can be metal flashing that
installs over the roof seam to prevent water from
leaking into the box.
WALK-IN COOLERS AND FREEZERS WITHOUT A FLOOR
Walk in coolers and freezers sometime come without a
floor. Special precautions need to be taken to eliminate
future problems. Walk-in coolers and freezers without a
floor must be installed on a ground contact concrete
floor. A cooler can be installed without insulating the
floor and a thermal break under each wall panel but we
recommend installing both. A freezer must be installed
on an insulated concrete floor and must include a
thermal break under each wall panel. To see recommended
example of a concrete pad for a walk in go to
An engineer or architect in your area will be required
for the final design of your pad to meet local code
approvals. If these precautions are taken you should
have trouble free performance with you walk in floor.
MANUFACTURER:
No matter what walk-in system you buy one of the most
important decisions is deciding which manufacturer to
purchase from. There are a lot of manufacturers of
walk-in coolers and freezers. They all have their niche
in the walk-in industry. The amount of service they
offer the end user varies. Look for a walk-in company
that has these traits.
1. The company should have been in business for at least
ten years.
2. The company should have a good web site explaining
the items they offer and information about the company.
3. The company should answer the phone with a person not
an answering device. Answering devices are for their
convenience and not yours. Should you call you should
always be able to talk to someone.
4. They should have clear quotes with itemized listing
of the items provided.
5. They should be very informative and pleasant on the
phone and treat you with interest and respect.
6. Their location and shipping cost need to be clearly
spelled out. Shipping is a very important item in
figuring up front cost of the project.
7. Check the warranty clearly so that you know what is
covered should problems occur.
8. Get references of other customers.
9. Make sure they are National Sanitation Foundation and
UL approved.
10. The company should specify how the walk-in is
manufactured with the types of materials are used in its
construction.
CONCLUSION:
Buying a walk-in cooler or freezer can be a large
investment. Make sure you are totally informed before
making a decision. Make sure you buy what you need and
not what a salesperson is trying to sell you. Remember
you are the one that will have to live with the walk-in
you choose. Good Shopping. |
|
|
 |
