Anyone can purchase, install, and service VRF equipment. However, just because they can doesn’t mean they should. Leaving the intricacies of VRF up to just anyone will likely result in a wide variety of problems.

Are you confident in the capability of the VRF service provider you’ve hired?

Below are 10 questions to ask when hiring an experienced VRF Provider.

• #1: Do you have tools such as hoses and manifold sets that are dedicated to the type of refrigerant oil shipped within the equipment?
  Answer: Yes. Cross contamination by different oils in VRF system can lead to problems.
• #2: What type of wire is required for VRF controls?
  Answer: it varies by manufacturer and is typically 16 or 18 gauge, 2-conductor, stranded, and one manufacturer require non-shielded while the others require shielded wire.
• #3 What pressure do you run for testing?
  Answer: most manufacturers recommend 550 psi, Mitsubishi recommends 600 psi.
• #4 How long do your run pressure testing?
  Answer: Most manufacturers require a minimum of 24 hour positive pressure test, however if ambient temperatures the pressure will too and therefore may require several days to verify no leaks.
• #5 Why do you pull a vacuum on a system?
  Answer: to remove moisture and verify no leaks.
• #6 What measure of vacuum needs to be pulled and for how long?
  Answer: lower than 500 microns and manufacturers vary on vacuum tests requirements, some say they should hold for 1-hour, others require 24 hours.
• #7 Some manufacturers recommend setting the system into forced evacuation during vacuuming; why?
  Answer: Forced evacuation opens all the electronic valves in the system to make sure your pulling a vacuum on the entire piping network.
• #8 How far away should an elbow be from an indoor unit connection?
  Answer: most manufacturers recommend 16 to 20”
• #9 What should you use to purge atmospheric air from the refrigerant piping when brazing joints?
  Answer: Dry nitrogen
• #10 How are extended warranties awarded on new installations?
  Answer: it varies by manufacturers and while some offer 10-year parts & 10-years compressor standard warranties without documentation, others require a very specific lists of items and run time to extend their warranties from 1-year parts & 7-years compressor to 10-year parts & 10-year compressors.

Not getting the right answers? Give us a call (817) 416-2881 or send us a message.