Refrigerant pipework installation

Pipe must be cut accurately to measurements established at the construction site and must be worked into place without springing or forcing. Pipes must be installed as to permit free expansion and contraction without damage to joints or hangers.

All due consideration and allowances shall be taken to keep refrigerant pipework clean and dry during the installation works. Arrange piping to allow inspection and service of compressor and other equipment in case of hvac maintenance works. Install valves and specialties in accessible locations to allow for service and inspection.

Installed piping must not interfere with the operation or accessibility of doors or windows and must not encroach on aisles, passageways, and equipment. Piping must be installed appropriately ranged continuous-duty temperature and pressure gauges designed for refrigeration service. Refrigerant copper pipe work shall be suitably identified and labeled where required in accordance to the project specifications and site conditions. If the system is found to be leak free, The final pressure readings for both strength and leak testing are to be witnessed and entered in the test and inspection reports.

The high side and low side of each completed refrigeration piping system must be pressure tested at a pressure not less than the lower of the system test pressure or the setting of the pressure-relief device protecting the high side or low side of the system as per approved specifications and manufacturer recommendation. Where pressure-relief valves are installed, position the three-way dual shutoff valves so that full test pressure is applied to both relief valves.

Do not attempt to repair any leak while the system is pressurized. If any leaks are found, relieve the test pressure and perform repairs. The pressure will be held for a period of 24 hours. If there is no visible loss of pressure after 24 hours, the line will be deemed to be gas tight.

In case a pressure gauge indicates the pressure drop, the testing operations connection and shut-off valve be first rechecked for leak and tightened as necessary.

If a pressure drop is still evident, then all joints and lastly the piping it self will be checked with soap and water solution. So if an electrical arc the current must have run down copper pipe and arced where the two metals made contact.

There was a copper deposit on inside of the cover where they had touched. Your opinion on what logically appears to be an install fault due to touching pipe and cover is very appreciated. If this could also denote a grounding issue that info is also appreciated. The pitting and crater and black marks look a lot like an electrical arc, not a vibration wear-through. Yes electrical arc does seem most likely. I do believe the proximity of the pipe touching the casing allowed the arcing to happen at this point - and there should not have been a point where the two touched - I believe am correct in saying this?

Where the electrical current came from is unexplained. Lightening is offered as an explanation but no sign of any strike anywhere. E,g The casing was clean all the way up - no scorching. Should I be looking for a possible electrical fault connected to the AC equipment. Yes certainly. I'd start by a visual inspection of the equipment for a loose wire, connection, or component, and also I'd look for burn marks or overheating signs inside the equipment.

From your photos I lack a more distant perspective view send that along if you can that might be informative. Absence of slack in the air conditioning system coolant lines at the compressor units can cause leaks: should the compressor move, perhaps because its supporting pads settle, there will be likely leaks at these lines.

You should review this question with your HVAC service person. This item may be deferred until next maintenance or service. Our refrigerant line photo below left shows worn insulation and a crimped condensate drain line. Our photo of a pair of outside compressor units below right shows what looks like a neat installation, but the mounting of the refrigerant piping against the building wall and absence of slack is just asking for a refrigerant leak in these systems.

Carson Dunlop Associates ' sketch illustrates the installation of the refrigerant suction and liquid lines and points out that the refrigerant lines should slope downwards towards the condensing unit - a detail that helps direct refrigerant oil back towards that component. Refrigerant lines need to be securely installed to minimize vibration that causes noise and damages piping. Reciprocating compressors, in particular, cause vibration. Steel braided flexible refrigerant lines a must for spring isolated reciprocating compressors minimize this vibration.

Refrigerant lines that rub against solid objects wear holes through copper and create a leak. For this reason, when refrigerant lines pass through walls, the line should pass through sleeved openings in such a manner that the lines do not touch.

There are several commercially available pipe clamping systems that allow pipes to be held rigid without causing damage to them. Most include some form of rubber grommet around the pipe, which is then secured within a bracket. Many building codes specify minimum support spacing.

Where piping is exposed to possible damage, the lines should be routed out of the way or be protected in some form of chase. Where refrigerant piping or condensate drains are routed through building walls, floors, or ceilings, if the holes drilled through framing members place the tubing too close to an interior or exterior wall surface, there is a risk that a drywall nail or screw, or an exterior siding nail will puncture the refrigerant lines.

We protect against this hazard by nailing standard nail plates across the face of each stud, joist, or rafter where this risk is present. Our refrigerant line photo left shows liberal use of these nail plates on the interior face of wall studs where the routing of refrigerant lines was close to the interior wall surface.

Because the builder had not yet completed the exterior siding just the OSB sheathing was in place , we also had to watch out for use of long siding nails that might puncture one of these lines. Outside the building in areas where this was a concern, because the sheathing was already in place, we simply marked "no-nail" areas on the OSB.

Refrigerant piping should be insulated. Manufacturers also recommend wrapping the insulated refrigerant lines exposed to outdoor weather, using an appropriate weatherproof tape. It's worth taking the time to read all of those details as the manufacturer has the same desire for a successful and trouble-free installation as the home or business owner or the HVAC installer. Among these instruction details you'll read how the manufacturer wants the refrigeration lines installed, including the following:.

When installing insulation over the refrigerant tubing, do not over-tighten the foam insulation typically held in place with plastic ties or tape. Crimping the insulation along its refrigerant tubing pathway creates points of less and possibly inadequate insulation.

Missing or inadequate refrigerant piping insulation means a system that operates at a lower efficiency and it risks condensate drips into problem areas such as wall or ceiling cavities - a mold risk.

I live in a townhouse and have a split air conditioner system. The compressor is currently on the roof, but it may need to be relocated to ground level. The other unit is in the attic. How far away from the house can the compressor be maximum, not minimum. I do not want to put the unit on my terrace, which is next to the house, because it would diminish our ability to use the terrace due to noise, etc. Could the unit be located approximately 37 feet away from the house without affecting it's function?

This would place it at the back of the garden, either behind a fence or obscured by a shrub. There is a more subtle technical concern with refrigerant velocity in the line. If the velocity is too low, refrigerant oil may not be properly distributed in the system.

In addition to total length of refrigerant piping, the number of elbows, bends, fittings, also affect flow and have to be taken into account. If there is not a "table" of distances and pipe diameters for a specific air conditioning system, then the manufacturer will expect the installer whose layout is different from the usual distances to make some measurements on the system and to adjust it accordingly.

In a nutshell, the size in diameter of the refrigerant suction and supply piping needs to be determined by the installer based on the distances involved, the equipment tonnage, changes in elevation between compressor and evaporator coil, the number and type of fittings in the refrigerant piping system, ambient operating temperature ranges, and other cooling equipment specifications given by the manufacturer. A cooling line that is too big in diameter OR too small in diameter can cause the equipment not to work properly or efficiently.

It's easy to get confused about pipe sizes or diameters when discussing flexible copper tubing. Refrigeration technicians often refer to flexible copper refrigerant tubing by its outside diameter or "OD" while plumbers usually refer to any piping by its inside diameter or "ID".

So when you are measuring or ordering piping, make sure you and your supplier are talking about the same size by using "OD" or "ID" in your measurements. Unused refrigerant piping or tubing should be stored with its ends capped to keep dirt and moisture out of the piping. Most HVAC systems that we have inspected and all that we have installed or repaired used soldered or brazed connections for copper refrigerant piping on both suction and high pressure lines. Some manufacturers, codes, and procedures also allow flare fittings - something we have used on some LP gas lines but in our opinion flare fittings are more leak prone than soldered connections.

We do not use compression fittings on refrigeration and air conditioning systems. In the opinion of some HVAC instructors, half of the leaks found in refrigerant piping are traced to defective soldered or flared connections so it's important to make these connections as close to perfect as you can during system installation or repair.

Sections of flexible copper tubing to be soldered or brazed together are connected using a procedure called swaging.

A swaging tool see our sketch above and our photograph at left is used to join similar-sized sections of refrigerant piping without requiring an additional coupling fixture. Swaging tools come in a range of sizes - two of mine [DF] are shown at left. Refrigerant tubing sizes are specified in O. The advantage of this approach is that we eliminate at least one soldered joint, increasing the reliability of the refrigerant piping system or other piping against leaks.

The swaging tool is inserted into the end of the copper tubing through a flare block or, if the installer is experienced, the tubing may be hand-held. The swaging tool is carefully hammered until it has expanded the copper tubing internal diameter ID sufficiently to permit it to slip over the connecting copper tubing section.

The interior of the enlarged end of tubing and the exterior of the factory-sized tubing that will insert into the enlarged mate are both cleaned, primed, or fluxed and soldered according to the manufacturer's instructions, typically using silver solder, or in some applications, brazing.

Watch out : improper swaging can damage copper tubing leading to future failures and leaks. This article describes three different temperature ranges for soldering copper piping or tubing along with some general copper pipe or tubing soldering advice. The copper tubing ends to be connected are cleaned, sanded, treated with soldering or brazing flux, and soldered or brazed.

When a capillary tube is to be soldered take are not to place soldering flux too far into the joint or the solder may flow over and close the end of the capillary tube. Soldered connections are much less likely to leak under the harsh conditions to which refrigerant piping is subjected: vibration, high pressures, high temperature swings, and outdoors, weather exposure. For example, measuring the refrigerant gas line pressure drop or temperature change on the suction line return to the compressor will show typically that a 4 degree temperature loss through the refrigerant line will result in an 8 percent loss in cooling capacity of the system.

Or on the discharge line output from the compressor will show typically that a 4 degree temperature loss through the refrigerant line will result in a 2 percent percent loss in cooling capacity of the system. ASHRAE[7] and some air conditioner manufacturers such as McQuay[6 ] provide a refrigeration piping guide that gives complete, detailed guidance and charts on refrigerant line sizing diameter as a function of length of run.

The company points out that the entire liquid refrigerant line is composed of more than just piping, and includes. Each of these devices or components contributes volume to the refrigerant piping system and must be considered in designing the "equivalent length" of the entire refrigerant piping system in order to determine the proper refrigerant charge.

For example,. In some refrigeration system designs, a low-temperature heat laden vapor line suction line is soldered alongside the high-temperature, high-pressure liquid refrigerant line.

The purpose of this line-to-line soldering is to act as a heat exchanger, to reduce the temperature of the liquid refrigerant that is going to enter the metering device TEV or cap tube , gaining some benefit to system operation - we want a lower refrigerant temperature at the point where the liquid refrigerant is about to be metered or released into the cooling coil evaporator coil in the air handler.

A second benefit of this heat exchange is that in the larger suction line entering the compressor, the refrigerant enters at a higher temperature, easing the compressor's job of compressing and raising the refrigerant temperature on the condenser side, so that the refrigerant is by being hotter better able to transfer heat to ambient air in the environment around the condensing coil. Other forms of air conditioner and heat pump economizers and economizer tricks of the trade are discussed.

On by mod - routing refrigerant piping under the roof decking. John, Thank you that's a helpful question. I don't think you will find an explicit statement in the model building codes about the distance below roof deck that's acceptable for routing air conditioning or heat pump refrigerant lines.

However the lines do need to be routed in a way that they're not exposed to damage. Because it's common for roofing nails to penetrate the roof deck it would make sense that the refrigerant lines would be several inches away from the deck. That's the same reasoning as applies to routing electrical wires that might be sent through rafters. Is there a code that states a minimum distance below a roof deck for refrigerant lines to be installed?

The refrigeration valve on my Trane condenser keeps releasing and a large amount of liquid is discharged. Is this normal? A friend of mine is having some problems with a room sized split air conditioner in his home. The unit is about three years old. A few months ago the unit stopped cooling and an air conditioning technician confirmed that the gas had leaked out. To inspect the lines some drywall had to be removed form a lowered ceiling, and upon inspection a cracked flare nut was found.

The technician said that this is a not uncommon occurrence. Have you ever come across cracked flare fittings in small air conditioners?