You're correct to be concerned about this. While I can't give a definitive "yes" or "no" answer without knowing your specific location and situation, here's a breakdown of the relevant considerations and codes that likely apply

Why this is a potential problem:
Corrosion

HVAC refrigerant lines (especially copper) can react with certain metals. Direct contact between the conduit and the line set can accelerate corrosion, especially if moisture is present.

Electrolytic Action

Dissimilar metals in contact with an electrolyte (water, especially rainwater containing pollutants) can create a small electrical current, leading to corrosion of one of the metals.

Physical Damage

Vibration from the HVAC system can wear on the conduit over time if they're directly touching. Sharp edges on the conduit or supports could also damage the line set.

HVAC System Performance

Strapping things too tightly can compress the refrigerant line, altering refrigerant pressure and affecting the efficiency of the HVAC system.

Accessibility

Attaching conduit to the same supports as the HVAC line can make it difficult to service or repair either system.

Workmanship

Using a single support for different systems may be seen as sloppy workmanship, potentially drawing scrutiny from inspectors.

Relevant Codes and Standards (General Guidance - Check Local Codes)


National Electrical Code (NEC)

The NEC primarily addresses electrical safety. While it may not explicitly forbid sharing supports, it emphasizes proper installation and protection of electrical systems. Specifically, look at:

NEC 110.12 Mechanical Execution of Work

This section stresses the importance of neat and workmanlike installations. Sharing supports haphazardly might be seen as a violation.

NEC 300.4 Protection Against Physical Damage

This requires that wiring methods be protected from damage. Direct contact with HVAC lines might be deemed inadequate protection.

NEC 300.11 Securing and Supporting

This section specifies how conduits must be supported. The method of support needs to be appropriate for the application and prevent damage.2.

International Mechanical Code (IMC) / Uniform Mechanical Code (UMC)

These codes govern the installation of HVAC systems. While not directly addressing electrical conduit, they often have sections on proper support and protection of refrigerant lines. Look for sections that specify: Clearances between refrigerant lines and other objects. Materials that are acceptable for supporting refrigerant lines. Prevention of vibration and physical damage to refrigerant lines. Workmanship requirements.3.

Local Building Codes

Your local municipality (city, county) will have building codes in place that may be more restrictive than the NEC or IMC/UMC. These local codes may specifically address this situation.

This is the most important source of information.4. Manufacturer's Instructions

Both the conduit manufacturer and the HVAC equipment manufacturer will have installation instructions. These instructions often specify acceptable support methods and materials. Following these instructions is crucial.5.

Best Practices

Even if not explicitly prohibited, it's generally considered best practice to avoid sharing supports between electrical conduit and HVAC lines, especially refrigerant lines. Use separate supports to maintain proper clearances and prevent potential problems.

How to Find the Correct Answer for Your* Situation


Contact Your Local Building Department

This is the

most important step. Call your local building department or electrical inspector and ask them directly about this. They can tell you if there are specific codes or regulations in your area that prohibit or restrict this practice.2. Consult a Licensed Electrician

A licensed electrician will be familiar with the NEC and local electrical codes and can advise you on the proper way to install conduit in your area.3.

Consult an HVAC Technician

An HVAC technician can advise on the best practices for installing and supporting refrigerant lines.

In summary:

While there may not be a hard and fast rule in every jurisdiction, sharing supports between electrical conduit and HVAC refrigerant lines is generally discouraged and may be prohibited by local codes. The best course of action is to check with your local building department and consult with qualified professionals. It's better to be safe and compliant than to risk code violations or damage to your systems. Flag for review