Kramer 4.5 HP Medium Temperature Walk-In Cooler Refrigeration System
The Kramer KFO450E4SDA outdoor condensing unit and two KL6A161ADASC low profile unit coolers form a factory-matched 4.5 HP medium temperature refrigeration package for large walk-in coolers up to and beyond roughly 20 ft × 40 ft. A single ZS33KAE scroll condensing unit feeds two three-fan KL6A161 coils, delivering high capacity split across two points in the room. Configured for R448A or R449A refrigerant, it is built for distribution warehouses, processing plants, and large cold-storage rooms.
Is a 4.5 HP Refrigeration System the Right Size?
This package is matched to medium temperature coolers up to and beyond about 20 ft × 40 ft holding 35°F to 38°F. At 25°F suction on R448A or R449A the KFO450E4SDA condensing unit produces 39,190 BTUH at a 95°F ambient, with a matched system rating near 39,104 BTUH at 25°F SST. That exceeds the largest box in the standard selection guide, so rooms this size and up should be sized from a calculated heat load.
The two KL6A161 coils carry more capacity than the paired KL6A141 coils of the 4 HP package, which extends coverage to the top of the standard cooler range and holds 34,960 BTUH at a 110°F ambient. Because rooms this large vary widely in insulation, door traffic, and product load, a computed load calculation is strongly recommended for final selection.
Ideal for: distribution warehouses, food-processing plants, central commissaries, and large commercial cold storage.
Representative box sizes: this package is commonly applied to coolers such as 20 ft × 40 ft and larger footprints determined by a calculated heat load.
Need more capacity? Step up to the Kramer 5 HP KFO500E4SDA Refrigeration System (dual coil). For a smaller room, see the Kramer 4 HP KFO400E4SDA system.
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.
What's Included
| Outdoor Condensing Unit | KFO450E4SDA — 4.5 HP Medium Temperature Condensing Unit |
|---|---|
| Indoor Evaporator | Two KL6A161ADASC Low Profile Unit Coolers |
| Application | Medium Temperature Walk-In Cooler Refrigeration System |
| System Capacity | Approximately 39,104 BTUH matched system (R448A/R449A, 25°F S.T.), across two coils |
| Refrigerant | R448A or R449A |
| Compressor | High-Efficiency Scroll Compressor |
| Evaporator Defrost | Air Defrost |
| Electrical | 208-230V, Single Phase, 60 Hz Condensing Unit |
| Evaporator Electrical | 115V |
| Factory Charge | Nitrogen Holding Charge — Refrigerant Field Supplied |
| Manufacturer Warranty | 1 Year |
The KFO450E4SDA condensing unit and the two KL6A161ADASC evaporators are also stocked individually for replacement work. Ordering them together as this matched package keeps the condensing unit and coil capacities aligned at design conditions. All units ship under a nitrogen holding charge, so plan on field-supplied R-448A or R-449A refrigerant and evacuation, charging, and commissioning by an EPA 608 certified technician.
Condensing Unit & Evaporator Features
KFO450E4SDA Outdoor Condensing Unit
- 4.5 HP ZS33KAE scroll compressor for medium temperature commercial refrigeration
- 39,190 BTUH at 95°F ambient and 25°F suction on R448A or R449A
- 34,960 BTUH still available at 110°F ambient and 25°F suction for rooftop and unshaded slab installations
- Integral liquid sub-cooling circuit providing an average 3°F to 5°F of sub-cooling 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 electronic air defrost timer
- 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 draw of 23 rated load amps and 146 locked rotor amps, on a 35 amp minimum circuit ampacity with 50 amp maximum overcurrent protection
Two KL6A161ADASC Low Profile Unit Coolers
- 18,800 BTUH per coil with R448A or R449A at 25°F SST and 10°F TD (16,100 BTUH on R404A), for a combined matched system near 39,104 BTUH
- Two multi-circuit distributor-fed coils for even refrigerant distribution across the coil face
- Factory-mounted thermostatic expansion valve, selected for R448A and R449A service
- Two KL6A161ADASC coils moving a combined airflow (2,355 CFM each) through a draw-through pattern for even temperature across a large room
- Dual-speed electronically commutated 115V motors with thermal overload protection, compliant with California Title 24
- 6 fins-per-inch coil using 3/8 in. enhanced copper tubes mechanically expanded into corrugated aluminum fins with die-formed collars
- Air defrost configuration intended for coolers held at 35°F and warmer, factory wired to screw-type terminal strips
- Embossed aluminum casing with baffled fan sections, NSF compliant and designed to mount flush to the ceiling
- Removable 3/4-14 NPT drain fitting at the bottom of the pan, replaceable without changing the pan
- Each coil UL and cUL listed with 3/8 in. liquid and 5/8 in. suction connections
Specifications & Manuals
Product documentation includes technical specifications, installation information, maintenance instructions, warranty information, and KL6 Series literature to assist with equipment selection, installation, and service. This system 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 cooler is the KFO450E4SDA designed for?
Large medium-temperature coolers up to and beyond about 20 ft × 40 ft holding 35°F to 38°F. Its capacity exceeds the largest box in the standard selection guide, so rooms this size should be sized from a calculated heat load.
How is the KFO450E4SDA different from the 4 HP KFO400E4SDA?
Both are dual-evaporator systems, but the KFO450E4SDA uses a larger ZS33KAE compressor and two KL6A161 coils in place of the KL6A141 coils, raising matched capacity from about 34,556 to 39,104 BTUH at 25°F SST.
How are the two evaporators positioned in a large room?
The two KL6A161 coils are typically mounted at opposite ends or sides of the room so cold air is introduced at more than one point, which evens out temperature and shortens recovery in a high-traffic space.
What size breaker does the KFO450E4SDA need?
The condensing unit calls for a 35 amp minimum circuit ampacity and a 50 amp maximum overcurrent protection on a dedicated 208-230V single-phase circuit; each evaporator is powered separately at 115V.
Will the system operate in cold outdoor weather?
Yes. Flooded head pressure control is standard, holding head pressure so the system keeps running as outdoor temperatures drop.
Can the condensing unit and evaporators be purchased separately?
Yes. The KFO450E4SDA condensing unit and the KL6A161 coils are stocked individually for service and replacement, though the matched package keeps their capacities aligned at design conditions.
Kramer KFO Condenser Technical SpecificationsKramer Installation GuideKramer Maintenence ManualKramer KL6 Technical SpecificationsKramer KL6 CatalogKramer Warranty
