Construction workers have difficulty choosing the better type of wire for construction, but both THHN wire and THWN cable are among the types of wire and cable used in construction. Their main difference is durability, THHN wire is more heat resistant, while THWN cable is more water resistant. Whether it is practical use or resistance, let's compare the difference between THHN wire and THWN cable, which type is better?

Electrical work is one of the most complex aspects of home improvement and construction. There are many variables between wire and conduit that affect installation and durability. So, what's the difference between THHN cables and THWN wires, and why does it matter?
Thermoplastic High Heat Nylon Coated Wire (THHN) cannot exceed 167 degrees Fahrenheit in humid environments. However, THWN wire is suitable for wet and dry conditions and is rated to withstand 194 degrees Fahrenheit. Dual rated cables are available as THHN cables and THWN wires with excellent heat and moisture resistance.
The difference between THHN wire and THWN cable
THHN wire and THWN cable differ in several unique ways, not least in their moisture resistance. Some wires, such as THHN wire, are simply not suitable for use in wet environments. However, THHN and THWN wires have more in common than you might think, depending on their construction. Both types of wires are wrapped with nylon and PVC insulation. THHN wire and THWN cable have different temperature ratings for wet areas, but that's essentially their only difference.

                                                      
THHN wire
Thermoplastic High Heat Nylon Coated or THHN wire is one of the more durable wires in construction. The wires are usually two conductors, and they can withstand temperatures as high as 194 degrees Fahrenheit, and they can drop to 167 degrees in cold conditions.
THHN wire cannot exceed 167 degrees Fahrenheit in particularly humid areas. THHN wire is less water resistant than THWN cable, but otherwise, the durability is the same. Professionals only use THHN wire in areas that are dry and will stay dry.
Some manufacturers produce one-piece cables that contain THHN, THWN, and THWN-2 wires. However, it is best to use THHN wires strictly indoors or away from wet conditions to avoid electrical damage and personal injury. THHN wire has three main components:
Wire: aluminum or copper
Conductor: Can be solid or stranded, depending on size
Sheath: Nylon outer sheath, polyvinyl chloride (PVC) insulation or vinyl
THWN cable
Thermoplastic hot water resistant wire or THWN cable if better suited for wet conditions. THWN cables are made of the same conductive aluminum or copper and nylon as THHN wires, but are slightly different. The main difference is that THWN wire can withstand 194 degrees Fahrenheit (90 degrees Celsius) when wet or dry.
This means THWN cables have more practical uses than THHN cables. You can use THWN cables indoors or outdoors, and they work in both wet and dry conditions. Some THHN wires have poor waterproof vinyl coatings, but THWN wires always have a nylon sheath.
Which is better, building wire THHN wire or THWN cable?
THHN wire is more efficient than THWN cable, but THWN wire is better for wet conditions. Wire from modern manufacturers is rated as both THWN and THHN wire, which is the best option. That way, you don't have to worry about moisture in areas where you run dual-rated cable.
THHN and THWN wires are almost identical except for their moisture resistance. Both THHN and THWN wires are made from the same basic materials and methods. THHN and THWN cables have three main components:
Wire: aluminum or copper
Conductor: Can be solid or stranded, depending on size
Sheath: Nylon outer sheath, polyvinyl chloride (PVC) insulation
The most important aspect of any THHN or THWN line is the nylon sheath. PVC inside the nylon coating provides insulation and protection from physical damage or temperature changes. Dual rated cables are usually as good in insulation as strictly THHN or THWN cables.

                                         

Why is THHN wire an excellent choice for resisting various outdoor factors?
THHN wire is gaining popularity in the Philippines as it is a cost-effective alternative to other types of construction wire for indoor and outdoor applications where longevity is important.
THHN wire is actually the abbreviation of thermoplastic high heat-resistant nylon coated wire, which belongs to connecting wire. This type of wire is used in nearly all residential and commercial structures. Depending on size, THHN wire is available with standard or solid conductors. It is made of aluminum and copper with insulated pvc. Many manufacturers also apply it with a nylon sheath to survive hotter and colder locations. This type of wire is used in building structures, but also in control circuit wiring, machine tools, and some other appliances. THHN wire cannot be used in all electrical equipment as it produces smoke when burned which can overheat the equipment and can be harmful.
THHN uses thinner insulated pvc material, which is a key factor in its electrical performance. This thinner insulating layer often causes current leakage and even failure during chemical or environmental exposure. Therefore, when we choose two kinds of wires and cables, we should make full use of their advantages and choose the wires and cables with the best effect.