HVAC contractors –
Don't get caught without a retrofit plan in 2015

The lifecycle of many older R22 HVAC systems will come to an abrupt end this cooling season. As a result, HVAC contractors will be facing a record number of repair, retrofit and replacement scenarios throughout the summer of 2015. Successful HVAC companies understand that overall profitability is achieved by finding ways to increase profitability within individual jobs.

Your ability to take advantage of these increased retrofit situations means applying your technical knowledge and expertise of how component choice, technique and focused decision processes save time on those individual jobs. Without a doubt, reducing field hours on individual jobs will enable you to do more jobs with the same work force and produce more profitable business volume as a result.

Let's take a look at some of the choices you'll need to make in order to save money during a retrofit.

Today, virtually all new mini-split systems, light commercial systems or unitary/residential systems utilize R410A Refrigerant. The US phase-out of R22 refrigerant is in its final stages and as older R22 systems fail, most new or replacement system repair components required necessitate a changeover to R410A refrigerant.

The changeover to R410A is happening at an incredible pace and there is a tremendous amount of discussion around availability of old refrigerant, incompatible refrigerants, incompatible oils, different operating pressures and their effect on components. Part of that debate includes the line set…. and not simply whether to change the line set or not, but more specific questions about tube size, tube thickness, vacuum, line pressures, connections, flare dimension, brazing issues, purging, cleaning, line filters, line driers, solvents, disposal and other issues that are critical to a successful repair, retrofit or system replacement.

In our last article, we demonstrated how 50% of a contractors' time is apportioned to tasks associated with the line set in a typical mini-split installation. Undoubtedly, this "critical component"…. the line set… should be considered more carefully in order to achieve higher job success rates for the HVAC contractors who will be performing more repairs, retrofits and replacements throughout 2015.

For this article, let's tackle the question we hear most often from HVAC contractors about retrofits.

"In an R22 refrigerant retrofit scenario, do I need to change out the line set… or can it be re-used?"

The "Smart Money" dictates that the copper line set should always be replaced – especially when you are going from R22 to R410A. The truth is, you just don't know what's in the existing lines and there's simply no guarantee that all of the contaminants (MO, acid, sludge, solder, corrosion, etc.) can be removed - even if the installer is very diligent and very careful. We've heard about newly converted HFC/POE's that burn out in just several months of operation. Evidence points to residual impurities from the old retained line sets. Besides the obvious risk, are there real financial savings to justify the re-use? The number of man hours plus the cost of chemicals, materials and other modifications can result in a higher total cost than that of a new line set. Finally, there's a good chance that the equipment manufacturer will void the warranty of their component(s) if the old line set was discovered to have been re-used.

How old are they, anyway?

Some installers say 10-year old lines are fine for re-use. And in a repair situation, we might agree. But if you are using old line set with new components, it's a lot like installing your old brake lines on a brand new car. Why take the chance?

PS – the copper we have today is NOT the same as the copper we had 30 years ago. Today, you have a choice of buying quality metal from reputable sources or cheap, recycled low grade copper that's filled with impurities, pinholes and thin enough to leak from the stamp marks.

But it runs under a concrete slab!

Well…you probably can't see it then, can you? So how do you know what condition it's in? Is it held together with quick connectors? Any kinks? Pinholes? Sheathing gone? We'd drain it, remove it and put in a new set.

Break out the tape measure.

In some cases, the decision to re-use an old line set gets trumped by a simple measurement. Always check the distance between the coil and the condensing unit. If it's beyond 50' a larger line size will be most likely be needed anyway. Time for a new line set!

Size matters – a lot

In some cases, line set sizing is an issue with R410A installations because if the line set for an R22 system has been properly sized, it will actually be oversized for R410A. This oversizing not only negatively affects system capacity but could result in improper oil return to the compressor, leading to compressor failure.

It's good to be well connected

Connections are more important than ever before. R410A systems put additional pressure on all the components throughout the system. Who wants a call back due to a bad braze or cracked flare? Oh yeah….lost refrigerant is expensive too – not to mention being harmful to the environment if it's R22!

Many HVAC Contractors prefer to use flare joints whenever possible. Factory flare joints are great, but the field-fabricated flare joints MUST be just as reliable. An experienced installer using a specific R410A flaring tool is required. Careful de-burring with a small drop of POE oil on the connection will result in a reliable, long lasting connection. The installation should be leak tested per the requirements of the system manufacturer - many of whom specify a 500 psig test pressure.

A specific R410A flaring tool is required because R22 flare connections have a smaller pitch than those for R410A flare connections. In addition, the overall diameter of the R410A flare is larger making the quality and consistency of the copper tubing that much more important.

This will be the year of the system retrofit! For certain, HVAC Contractors can expect a lot more retrofits in the months to come along with a continual rise in the price of Refrigerant R22. Remember, R22 and R410A are incompatible…. Period! The existing R22 system components like the condensing unit and cooling coil are not suited to the new R410A refrigerant that operates at higher pressure. The line set is affected by the change in refrigerant as well as your tools, vacuum pumps, gauges and hoses.

In conclusion, your approach to every retrofit should be based around a conscientious and diligent review of the manufacturer's specifications and installation instructions, good job planning, labor allocation, equipment/materials procurement and excellent on-the-job craftsmanship. This forward-looking mindset will not only enhance your company's reputation, but reduce field hours on individual jobs - enabling you to do more with the same work force and increase profitable business volume as a result.