Webinar: HVAC Claims Repair versus Replace Presenter: Curtis VanNess, General Manager HVAC Forensics Webinar Questions & Answers Q: Can you explain how a swamp cooler works and/or is different? A swamp cooler uses water to absorb and remove heat. They are not effective in all climates. Another common name is an evaporative air cooler. These machines basically use water as the refrigerant. The water passes through a coil and fan blows through the coil. The result is cooler air. Q: I handle larger losses that often involve displacement of the policyholder and sometimes up to a year of dormancy for the heating system. At the end of these long periods there are occasions where the system simply does not restart, or that is the contractor s claim. What steps should we take in terms of protecting otherwise undamaged systems? How soon should these steps be taken? Do we do anything differently with an oil system versus a natural gas or LPG system? Get an inspection as soon as possible to document the condition of the system. Equipment fuel types vary but they generally have the same components. Q: Is there a way to tell the SEER of an exterior/interior compressor unit by the model/serial? Yes the nomenclature varies by manufacturer but most can be decoded by using the unit s model number. Q: I've seen fins which have horizontal lines around them. Can you still comb those fins? Some units have a metal cage around them to help protect the coil. In cases where the fins can be combed the answer is yes. The metal cage can be removed to easily access to the coil. Q: How many hours to change out a coil on a 5-ton RTU? The process for changing out a coil on an RTU is as follows: remove the refrigerant, dismantle the unit, remove the coil, crane lift new coil into place, braze in new coil, perform triple evacuation, install refrigerant. This usually takes two guys around 4-5 hours. Q: A limb hit a unit. Insured is saying they were told this could loosen the weld joints which will show up at any time? I have seen large trees fall on air conditioners. The damage is usually severe enough to change the unit. In these cases the shell has been crushed. If a small limb hits a unit and does little damage to the shell, then it is less likely future damage would occur due to a small hit. Q: How many times can the fins be combed? This will depend on the construction of the coil. If the fins are thicker (like Trane coils) then they are more likely to be combed many times. Q: I would like to know if when we change the compressor we need to change the R-22. Using new refrigerant is best practice. However, if we know the refrigerant in the system has not been contaminated then we can reuse it.
Q: For heat pumps what has to be changed out if 13 SEER when damaged due to wear and tear? If it is an R-22 heat pump and it is determined that you are going to replace the equipment, then you will have to purchase 14 SEER R-410A equipment. You have to change the heat pump and air handler because the indoor coil is part of the air handler. Q: What is the cost to comb out fins on a commercial HVAC system? The cost to comb depends on several factors. One is the amount of damage and the other is difficulty of combing due to the construction of the coil. A general rule of thumb on pricing is $100 an hour. For coils with 1 10% damage the estimated cost to comb can vary from $200 to $500. Q: What is the best way to determine whether or not a unit is leaking? With low refrigerant levels your system will not cool at all or it may run a long time. A thorough inspection of the indoor unit and outdoor unit for refrigerant leaks using visual and leak detecting devices is the best way to determine if a leak is present. Refrigerant gauge measurements as well as superheat and subcool measurements are used to determine if the system has the correct levels of refrigerant. Q: How do you tell (what should you photograph) to show there is a heat element to the AC unit? On a heat pump system your indoor unit (air handler) has heating elements on the inside. The exhaust pipe on a unit indicates the system is a furnace. Q: As a desk adjuster, sometimes a field inspector says a unit can be combed and the insured will call and say it can't. Thoughts on that? I've told them to check with another company for repairs as sometimes it is definitely light damage in photos. There are some contractors that do not have the experience of combing units or they simply do not want to it because they want to sell them new equipment. Q: Does lightning tend to affect geothermal systems vs. other types since the lines go in the ground? Most Geothermal system piping is not conductive and therefore less susceptible to lighting damage. It is very rare to find a leak in underground piping on these closed loop systems. Q: In a situation where the outside unit is stolen, what other operations are required other than simply replace the unit? You will have to replace the indoor coil when replacing the unit. On a heat pump you will have to replace the air handler. Q: Insured states they will not agree to a comb, based on what Lennox says about combing." Can you explain? If corrosion is present then the coil cannot be combed. They might be referencing the white coil class action suit. Here is one article that references this condition. http://www.coolingpost.com/world-news/lennox-settles-white-coil-class-action/ Q: Do warranties typically cover or deny lightning? Most warranties state lightning damage is not covered. However, when it comes to compressor failures a contractor cannot determine cause of failure unless they cut it open. Therefore, we send warranty failed compressors back to the manufacturer.
Q: The biggest issue that always seems to come up in fire losses is that the HVAC contractors typically say that the entire system (interior and exterior) need to be replaced due to "compatibility" issues when only the interior air handler is affected. Is this accurate generally? I would say generally you can replace just the inside unit. You can still get multi-refrigerant indoor coils. However, the code in different states may require total replacement. Q: When refrigerant lines have been exposed, is it better to repair or replace, considering the cost; this is for an R22 unit? If moisture has entered the refrigerant lines, it would be recommended to replace the system. Q: What is the cause of an outside unit to freeze (meaning it has ice all over the system)? This occurs when the heat pump does not go through its defrost cycle. Common failures are the temperature sensors or defrost board. This can also happen during normal operation with very low ambient temperatures. Q: Is there any big difference between residential & commercial HVAC units or do the systems basically work the same way? They operate similarly. A commercial unit may have more bells and whistles like safety devices to protect the compressor. Q: Are float switches required now on all units, or only on units that are on the second floor? The IMC code book states a unit must have a float switch or an auxiliary drain line, if the unit is located where it can cause damage as a result of overflow from the equipment s primary condensate removal system. Q: Is there another alternative product to R-22? Maybe a refrigerant called 407C? There are several different refrigerants that can be used instead of R-22. Some of the replacements including R-407C and require the metering device to be changed. There are some other drop-in replacement refrigerants that do not require changing the metering device. A common counter to using a drop-in is the reported loss of efficiency. Q: Is it usually recommended that a HVAC exposed to heavy smoke & soot be replaced? Yes and possibly the ductwork. Q: Why are the fins of commercial roof top units often exposed to the elements & hail in particular? There is nothing to protect them from the elements when installed on a roof. Whereas units on the ground may have trees or walls to prevent damage to the coils. Q: How does water enter into the system? Water or moisture from air can enter the refrigerant circuit if there is a refrigerant leak or by poor maintenance/install practices. Q: Can landscaping right next to or touching the outdoor unit cause issues to a system? If the landscaping shrub or plant is blocking the airflow around the outdoor coil, then it can cause the compressor to overwork and possibly cause a failure in due time.
Q: Can a lack of maintenance contribute to an over surge? With poor maintenance practices your HVAC system is far more susceptible to a failure. In the event of a power surge or lightning event, failures can occur with different levels of dirt on the coils or filter. A lighting-induced power surge does not pick and choose based on how often you perform maintenance. Q: Is having a compressor near a water Aerator an issue for corrosion of the coil - sulfur gas? Environmental factors affects corrosion of coils. Yes. Q: In a fire loss will exposure to hot smoke destroy an interior air handler? The heavy soot or smoke can cake to all surfaces including hard to clean insulation and blower motor windings. Yes an intense fire can destroy an indoor unit, especially if it was running during the event. Q: With the introduction of 14 SEER standards, is it necessary to replace both components of a split system? Yes, we will be replacing the air conditioner and indoor coil or heat pump and air handler. Is it still possible to replace an older compressor rather than the entire system? Yes, compressors are available for purchase on most HVAC systems. Q: If the outside unit is 14 SEER, what is the minimum SEER recommendation for the indoor coil? The minimum recommendation is 14 SEER. Q: Would a thermostat be a cause for an HVAC system not to work? Yes, the thermostat turns on the system for a demand for cooling or heating. It is a temperature controlled switch. Q: At what point can the fins not be combed? When the hail dents are deep and the fins tear when attempting a repair. Q: Is it common that an escape of water from a plumbing leak damages an HVAC unit? What are some water damage identifiers? This is possible if the controls or motor have failed or been wet. We can find water marks, wet insulation, and/or moisture on key components. Q: Can an aluminum coil be effectively soldered? It can but it requires a very skilled hand. This repair is not commonly taught or practiced in the field. Q: Can the new "micro channels" on rooftop units be repaired? Hail dents to these coils cannot be repaired. Some manufacturers sell repair kits for these. But again this repair is not commonly taught or practiced in the field. Q: Is it absolutely necessary to change out the interior air handler evaporator coil when converting the outdoor R- 22 Condenser to an R-410A Condenser? Can the R-407C Freon be used in the R-410A Condenser & keep the existing interior coil & system in place? Manufacturers recommend changing out the indoor coil when changing from R-22 to R-410A. R-407C is compatible with POE oil found in R-410A units. POE oil is not compatible with mineral oil found in R-22 units. However, the cost to change the metering device and make sure all the mineral oil is out of the indoor coil would cost more than replacing the indoor coil.
Q: Is there a solution to clean the coils? There is coil cleaner. Some of these cleaners are acidic and can cause damage to the coil. Good clean water on the typical residential coil is recommended. It the coil is extremely dirty or cakes with grease then it would be recommended to use a cleaner with plenty of water. Q: Is regular maintenance on home systems worth the cost? I get this question a lot from clients on what to expect from an HVAC contractor when he comes to an insured s house or even their own. Are preventive maintenance contracts worth the cost? The answer is yes they are worth the cost as long as you have some basic understanding of your system, component failures and expectations from your service professional.