If you're an admin buyer like me—someone who handles orders for the office, kitchen, or warehouse—you've probably been handed a spec sheet for a bohn freezer unit and told, "just get the best price." I've been there. In 2022, I was tasked with sourcing a new evaporator for our walk-in cooler. I thought I had it figured out. Got a great price. Then the installers showed up and told me the wiring diagram didn't match our setup. That was a $600 mistake in change orders and lost inventory.
Here's a 5-step checklist I now use to avoid that headache. It's for anyone ordering commercial refrigeration equipment—especially Bohn products—who wants the specs to work the first time.
Step 1: Match the Wiring Diagram to Your Power Supply (Don't Assume)
The biggest mistake I see is people glancing at a bohn evaporator wiring diagram and assuming it matches their facility. You can't. You have to check the voltage and phase.
- Single-phase vs. three-phase: Your building might have one or the other. A Bohn evaporator rated for 208V single-phase won't work on a three-phase line without a phase converter. I almost made this error in 2023 when ordering for a new construction project.
- Control voltage: Look at the transformer. Is it 115V or 24V for the controls? I once ordered a unit that required 24V controls, but our building's control system was 115V. Add a transformer? Sure. But it's an extra cost and a headache you don't need.
To be fair, Bohn's technical documentation is pretty good. But you still need to read the actual wiring diagram, not just the model number. The model number tells you the capacity. The diagram tells you if it'll actually turn on.
Quick check: Ask for the specific wiring diagram PDF before placing the order. Look for the voltage and phase labels. If it says "V/Hz/Ph" and it doesn't match your facility's power supply, stop and ask questions.
Step 2: Verify the Dimensions Against Your Stand Up Freezer or Walk-In
You're probably ordering this for a stand up freezer or a walk-in cooler. But "standard size" is a dangerous phrase.
I learned this the hard way. In 2021, I ordered a condenser that was supposed to fit our existing walk-in. The unit was 3 inches too wide. The installation crew had to reframe the doorway. Cost: $450 and a delay of 3 days.
Here's what to do:
- Measure the rough opening or the mounting area in your stand up freezer. Note the maximum width, depth, and height.
- Get the Bohn evaporator or condenser dimensions from the spec sheet. Check not just the unit dimensions, but also clearance for air intake and service access.
- If you're replacing an old unit, do not assume the new one is the same size. Bohn designs change. You need actual, current measurements.
I now keep a folder of dimension spec sheets for our 3 locations. Saves me a call to the contractor every time.
Step 3: Check the Refrigerant Type (It's a Legal Thing Now)
This might be the most overlooked step. Refrigerant regulations are changing fast. Per the FTC's Green Guides and EPA regulations, if you're installing new equipment, you need to check the refrigerant type. Some older Bohn units used R-404A. Newer ones might use R-448A or R-449A. They are not interchangeable without a system redesign.
Per EPA regulations effective 2023, the manufacturing of equipment using high-GWP refrigerants like R-404A is being phased down. Verify your unit's refrigerant at the EPA's SNAP program website.
I ordered a Bohn condensing unit in early 2024 that was listed as "R-448A." That was fine for our operation. But if I had ordered an old R-404A unit, we would have been locked into an expensive and soon-to-be-scarce refrigerant. Check the tag on the unit before you buy.
Step 4: Don't Forget the Accessories (Especially the Ice Maker Machine Connection)
If your system includes an ice maker machine or other secondary equipment, you need to make sure the Bohn system has the right connections and capacity.
I once ordered a chiller for a setup that also had an ice maker machine. I didn't check the Bohn condensing unit's capacity for both. The unit was powerful enough for the walk-in, but when the ice maker kicked on during peak heat, the system couldn't keep up. We had melted ice and a complaint from the kitchen manager.
Before ordering:
- List all connected equipment (walk-in cooler, stand up freezer, ice maker, etc.)
- Add their BTU loads together. Compare to the Bohn unit's total capacity.
- Check if the unit has an auxiliary port or connection for the ice maker. Some Bohn condensers do. Some require a separate line.
It's a small detail, but it's the kind of thing that makes you look bad to your team. A vendor who proactively asks "Do you have an ice maker connected?" is a vendor who saves you from a call from operations.
Step 5: Confirm the Control System Compatibility (Can Nest Thermostat Replace Heating and Air Conditioning)
This is the weird one. I've seen people ask if a can nest thermostat replace heating and air conditioning system. For a commercial refrigeration system, a Nest won't work (it's a residential thermostat). But you do need to think about control compatibility.
What I mean is:
- Does the Bohn unit use a standard pressure control or an electronic controller?
- Does it need to talk to a building management system (BMS)?
- If you're using a smart thermostat for the HVAC in the building, the Bohn system is usually separate. But if you have a combined HVAC and refrigeration system (rare in commercial, but possible), you need to check the logic.
A colleague of mine had a building where the HVAC was controlled by a Nest system. When the heating was off, the refrigeration system was supposed to compensate. It didn't. The Nest didn't talk to the Bohn controller. Result: a frozen walk-in and another service call.
The lesson: If the building's thermostat is smart, the refrigeration controller needs to be compatible. Bohn offers electronic controllers that can interface with some BMS systems. Specify this upfront.
One More Thing: The Price Trap
I've learned to ask "what's not included" before "what's the price." A vendor who lists all fees upfront—even if the total looks higher—usually costs less in the end. That $200 cheaper unit? It didn't include the wiring kit or the certificate of insurance. By the time I added those, I was at the same price as the transparent vendor.
Prices as of January 2025: A Bohn evaporator unit for a small walk-in cooler typically runs $1,200–$2,500 from authorized distributors. Condensing units run $2,000–$4,000. Verify current pricing at bohn.com.
Take this checklist with you next time you order. It's saved me from three expensive mistakes in the last two years. Hope it does the same for you.
