CRC installation, operation, and maintenance guidelines. Use the checklist section to verify correct installation before startup.
Upon Delivery — Before Signing
- Inspect crate/box for external damage before signing the freight bill
- Look for: indentations, protruding nails, forklift marks
- Inspect interior contents carefully for concealed damage
If Damage Is Found
- Accept the shipment — do not refuse delivery
- Note “DAMAGED” clearly on the freight bill before signing
- Do not move damaged equipment or discard packaging
- Contact CRC immediately to report the damage
- Wait for carrier inspection before proceeding with any repairs
- Contact CRC again once inspection is complete
⚠️ Accepting a damaged shipment does NOT hold you liable — as long as “DAMAGED” appears on the freight bill. Failing to note damage on the freight bill forfeits your claim.
Handling & Mounting
- Lift by casing only — never by connections, headers, tubes, or fins
- Install coil and piping on separate supports
- Use backup wrenches on all connections — never torque against coil headers
- Position tubes horizontally using a level
- Special drain headers available if leveling the coil is not possible
Piping Connections
- Supply water → bottom connection on the leaving-air side
- Return water → top connection on the entering-air side
- Run water counter-flow to air for maximum heat transfer efficiency
- Always use thread tape or pipe compound + backup wrench on threaded connections
- Pipe velocity: do not exceed 8 FPS (preferred range: 2–6 FPS)
- Under 1 FPS → risk of laminar flow (poor heat transfer)
- Over 8 FPS → risk of tube erosion
- Recommended friction loss: ~3 feet per 100 feet of pipe
- Support all piping independently — never let pipe weight stress coil connections
Filling & Venting
- Open the vent at the top of the supply header before turning on water
- Fill until a steady stream flows from the vent, then close
- Re-vent periodically with fluid flowing to clear accumulated air pockets
Cooling Coil Specifics
- Drain pans must extend minimum 10 inches from the coil’s leaving-air edge
- Drain line trap depth: 2× the negative static pressure of the unit
- For stacked coils: install intermediate drain pans with plastic tubes draining from upper units
⚠️ Minimum entering air temperature: 40°F. For applications below 40°F, use glycol or brine solutions — see Freeze Protection section.
Handling & Mounting
- Lift by casing only — never by connections, headers, tubes, or fins
- Non-cased coils: pitch ¼ inch per foot toward the return connection for condensate drainage
- Steam distributing (non-freeze) coils: pitch ⅛ inch per foot of finned length toward return connection — critical for freeze protection
- Ensure adequate piping flexibility to accommodate thermal expansion
Piping Connections
- Steam supply → upper connection on the leaving-air side
- Run steam counter-flow to air for maximum heat transfer
- Do not reduce pipe size at the return connection
- Install vacuum breakers and air vents on all applications
- All piping must be supported independently — no pipe weight on coil connections
- Use float and thermostatic (F&T) traps for both high- and low-pressure systems
- Position traps minimum 12 inches below the coil return connection
- Each individually controlled coil or coil group requires its own trap
- Series coil arrangements: each coil or bank requires a separate trap
Control Valves
- Modulating valves must be sized properly — DO NOT OVERSIZE
- Steam distributing (non-freeze) coils: must use modulating control valves — on/off valves NOT permitted
Coil Type Selection Guide
| Coil Type | Use When | Control Valve | Min Steam |
|---|---|---|---|
| Standard steam | Entering air always ≥ 40°F | On/off OK | Any pressure |
| Steam distributing (non-freeze) | Outside air pre-heat, below-freezing entering air | Modulating only | 5 psig min |
🚨 Non-freeze coils require minimum 5 psig steam supply for proper freeze protection.
Receiving & Preparation
- Coils arrive with nitrogen holding charge — exercise caution when opening connections
- If no nitrogen charge on arrival: contact factory before installing
- Clean distributor connections with emery cloth if soft solder was factory-applied
Refrigerant Line Sizing & Routing
- Use long radius fittings for all bends — minimizes pressure drop
- Use nitrogen-charged, capped piping during installation to keep moisture out
- Liquid line: maintain 5°F sub-cooling at the expansion valve
- Pitch horizontal suction lines toward the compressor
- Install traps at riser bottoms and every 15 feet on vertical risers for oil return
- Insulate suction line completely with appropriate insulation wall thickness
- Install pressure tap on the leaving side of the evaporator
Filter-Drier & Sight Glass
- Install filter-drier upstream of the expansion valve
- Maximum pressure drop through filter-drier: 2 PSI
- Install moisture indicator/sight glass between the expansion valve and filter-drier
- Install liquid line shutoff valve with access port near the condenser
- TEV must be selected for proper size, capacity, and the refrigerant being used
- Select valves with external equalizer connections
- Mount sensing bulbs at 10 o’clock or 2 o’clock position on suction line — never on top or bottom
- Do NOT overtighten the bulb clamp
🚨 Disassemble the TEV before brazing connections. If necessary, wrap the valve in a cool wet cloth while brazing.
Refrigerant Notes (Post Jan 1, 2026)
- New split systems must use refrigerants with GWP <700
- R-454B: standard for Carrier, Trane, York, Lennox ducted residential/light commercial
- R-32: standard for Daikin, Goodman, Amana ductless mini-splits
- R-454B and R-32 coils are NOT interchangeable with R-410A coils
- Existing R-410A systems may be serviced and repaired indefinitely
- Use glycol solution if operating near or below freezing temperatures
- Minimum entering air for standard coils: 40°F — below this requires glycol or non-freeze coil design
To Winterize a Water Coil
- Fully drain the coil
- Blow out with compressed air through the return (top) connection
- Disconnect supply and return lines until ready to refill
⚠️ When draining coils, all water may not drain completely. Always blow out with compressed air after draining.
Glycol Freeze Points Reference
| % Ethylene Glycol | Freeze Point | % Propylene Glycol | Freeze Point |
|---|---|---|---|
| 10% | 25°F | 10% | 26°F |
| 20% | 17°F | 20% | 19°F |
| 30% | 5°F | 30% | 8°F |
| 40% | -13°F | 40% | -7°F |
| 50% | -34°F | 50% | -29°F |
- Average coil life: ~15 years; well-maintained coils can last 25–30 years
- Disconnect power and lock out/tag out (LOTO) before any cleaning
Cleaning Procedure
- Always clean from the leaving-air side — pushes debris out, not deeper into the fin pack
- Light dirt: vacuum or soft-bristle brush
- Heavy buildup: cold water with detergent, or commercial coil cleaner; pressure washer (use carefully to avoid fin damage)
- Rinse thoroughly after using any cleaning agent
🚨 Do NOT clean refrigerant coils with hot water or steam — causes dangerous high-pressure buildup inside tubing.
- Avoid acidic cleaners
- Alkaline cleaners must have pH ≤ 8.5 OR include an aluminum corrosion inhibitor
- Always follow SDS/safety instructions and use appropriate PPE
Fin Straightening
- Use fin combs sized to the coil’s FPI specification — wrong size will cause damage
- Inspect fins after every shipping delivery or servicing event
- Work carefully — fins are thin aluminum or copper and bend easily
⚠️ Steam itself is not corrosive. Steam condensate can be, if contaminated. Coils developing pin holes — especially repeated failures — signal corrosive condensate, not simply worn-out coils.
Three Primary Corrosive Agents
| Agent | Common Source | Affects |
|---|---|---|
| Oxygen | Air leakage into condenser | Copper alloys |
| Carbon Dioxide (CO₂) | Air leakage or feed-water alkalinity decomposition | All copper alloys |
| Ammonia | Contamination or pH chemical overdosing | Copper alloys |
Standard water treatment tests typically do NOT test for oxygen, CO₂, or ammonia — so corrosion can go undetected until pin holes appear.
Diagnosis & Solutions
- Pin holes in tubes = direct indicator that corrosive agents have reached damaging levels
- Test the condensate immediately after the first pin hole — do not simply replace the coil
- Solution 1: Replace with stainless steel tubes and headers
- Solution 2: Cleanse the system of corrosive agents (addresses the root cause)
🚨 Thicker tube walls do NOT solve corrosion. It is the material’s corrosion resistance that matters, not thickness. Replacing with the same-material coil without fixing water chemistry = rapid re-failure.
| Coil Type | Max Pressure | Notes |
|---|---|---|
| Steam coils | 150 psig saturated steam | — |
| Fluid coils (standard) | 300 psig | 250°F max for single-phase fluids |
| Fluid coils (elliptical ½″ × 0.016″) | 250 psig | — |
| Fluid coils (elliptical ½″ × 0.025″) | 450 psig | — |
| Evaporator coils | 750 psig | R-410A rated |
| Condenser coils | 750 psig | R-410A rated |
ℹ️ All coils pressure tested at 550 psig using dry nitrogen, submerged under water, with dual-operator verification before shipping.
General — All Coil Types
Water Coils
Steam Coils
Refrigerant / DX Coils
- All installations must comply with local codes and standards — non-compliance may void manufacturer warranty
- Do not substitute a water coil for a steam coil — completely different construction, pressure ratings, and tube wall requirements
- Refrigerant coils for R-454B or R-32 are NOT interchangeable with R-410A coils
- Do not clean coils with hot water or steam
- Do not use acidic cleaners or alkaline cleaners above pH 8.5 without aluminum corrosion inhibitor
- Always lock out/tag out power before cleaning or servicing any coil
📞 For questions or coil replacements, contact CRC directly.
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