Kramer 3.5 HP Low Temperature Refrigeration Condensing Unit
The Kramer KFO350L4SDA is a 3.5 HP outdoor condensing unit built for low-temperature walk-in freezer refrigeration. A ZF11K4E low-temperature scroll compressor delivers approximately 11,140 BTUH at a 95°F ambient and a -20°F saturated suction temperature on R448A or R449A refrigerant, holding a walk-in freezer near a -10°F box temperature. It is the outdoor condensing unit only and matches a Kramer low-profile electric-defrost evaporator to complete a walk-in freezer system.
Is a 3.5 HP Low-Temp Condensing Unit the Right Size?
At 95°F ambient and -20°F SST the KFO350L4SDA produces about 11,140 BTUH on R448A or R449A, matched to a walk-in freezer holding roughly -10°F. Freezer load is driven by insulation R-value, outdoor ambient, door-opening frequency, the quantity and entering temperature of product frozen or stored each day, and required pull-down time, so size from a calculated load rather than floor area alone.
This listing is for the outdoor condensing unit only. To build a complete walk-in freezer system, it pairs with a matched Kramer low-profile unit cooler with electric defrost — the KFO350L4SDA is factory-matched to the KL6E090DDASC evaporator. Low-temperature evaporators use electric defrost rather than air defrost, because a freezer coil accumulates frost that off-cycle box air cannot clear.
Ideal for: high-capacity walk-in freezers in grocery distribution, commissary operations, and frozen storage.
Need more capacity? Step up to the Kramer 4 HP KFO400L4SDB Low-Temp Condensing Unit. For a smaller freezer, see the Kramer 3 HP KFO300L4SDA Low-Temp Condensing Unit.
Recommended refrigeration applications are general guidelines only. Actual system requirements depend on insulation, ambient conditions, door openings, product load, and operating temperature. Request free sizing assistance, contact Budget Heating, or call 813-885-7999.
Condensing Unit Specifications
| Condensing Unit Model | KFO350L4SDA |
|---|---|
| Horsepower | 3.5 HP |
| Compressor | ZF11K4E Low-Temperature Scroll Compressor |
| Application | Low Temperature Walk-In Freezer Refrigeration |
| Refrigerant | R448A or R449A |
| Capacity | Approximately 11,140 BTUH at 95°F ambient and -20°F SST |
| Electrical | 208-230V, Single Phase, 60 Hz |
| Minimum Circuit Ampacity | 22.4 A |
| Maximum Overcurrent Protection | 35 A |
| Matched Evaporator | KL6E090DDASC Low Profile Unit Cooler (sold separately) |
| Factory Charge | Nitrogen Holding Charge — Refrigerant Field Supplied |
| Manufacturer Warranty | 1 Year |
Condensing Unit Features
- 3.5 HP ZF11K4E low-temperature scroll compressor rated for walk-in freezer duty
- Approximately 11,140 BTUH at 95°F ambient and -20°F saturated suction on R448A or R449A
- Configured for R448A and R449A, the current-generation replacements for R404A in low-temperature refrigeration
- Integral liquid sub-cooling circuit for improved efficiency and stable expansion valve operation
- Flooded head pressure control standard, supporting operation as outdoor ambient temperatures drop
- Generously sized condenser coil with enhanced copper tubes and aluminum fins in an all-weather painted galvanized steel housing
- Ships under a nitrogen holding charge, with a refrigerant receiver, isolation valve, and pressure relief plug
- Liquid line with sealed filter and sight glass, factory crankcase heater, and defrost termination provisions for a matched electric-defrost evaporator
- Fixed high-pressure and adjustable low-pressure controls, with quick-access shut-off valves and color-coded point-to-point wiring
- 208-230V single phase, drawing about 16.3 rated load amps and 109 locked rotor amps, on a 22.4 amp minimum circuit ampacity and 35 amp maximum overcurrent protection
Specifications & Manuals
Product documentation includes technical specifications, installation information, maintenance instructions, and warranty information to assist with equipment selection, installation, and service. This condensing unit carries a 1 year manufacturer warranty; see the Kramer warranty documentation above for full coverage terms and conditions.
Frequently Asked Questions
What size walk-in freezer is the KFO350L4SDA sized for?
It produces about 11,140 BTUH at 95°F ambient and -20°F SST, suiting a large, higher-throughput walk-in freezer near -10°F. Verify with a calculated freezer load.
Does this condensing unit include the freezer coil?
No. The KFO350L4SDA is the outdoor condensing unit only; a matched low-profile electric-defrost evaporator is required and sold separately.
How does the KFO350L4SDA compare to the 3 HP and 4 HP units?
At 3.5 HP it sits between the 3 HP KFO300L4SDA (about 9,000 BTUH) and the 4 HP KFO400L4SDB (about 12,990 BTUH), for a freezer load between those two sizes.
What box temperature is this unit intended for?
It is a low-temperature unit rated at a -20°F saturated suction temperature, which typically holds a walk-in freezer box near -10°F depending on load and coil selection.
Is the KFO350L4SDA suitable for outdoor installation?
Yes. It is an outdoor-rated condensing unit; the matched KL6E090DDASC evaporator installs inside the freezer.
Does the KFO350L4SDA ship with refrigerant?
No. It ships with a nitrogen holding charge, and R-448A or R-449A is field supplied and commissioned by an EPA 608 certified technician.
Kramer KFO Condenser Technical SpecificationsKramer Installation GuideKramer Maintenence ManualKramer Warranty
