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May 2023

2J Supply Newsletter

Presenting the New 2J Supply Newsletter 

Welcome to the first edition of our 2J newsletter! This newsletter will share the latest industry news, events, training, and more resources for HVAC contractors.

The latest industry news includes Understanding SEER and SEER2 and what it mean for homeowners. Additionally, the adoption of heat pump units and the air source heat pump market is discussed. And we’ve created a section on HVAC training and education that discusses the importance of monitoring compressor discharge temperature and making the decision to repair or replace your evaporator coil.



News

Understanding SEER and SEER2: What it means for homeowners.


As the HVAC industry transitions to the new efficiency metric, SEER2, you may be wondering what this means for your home’s heating and cooling system. Seasonal energy efficiency ratio (SEER) has been the standard measure of efficiency for heat pumps and air conditioning systems, but it can be a confusing term for homeowners.

To provide some context, SEER is the ratio of total cooling capacity during normal periods of operation divided by the total electric energy input over that same period. The higher the SEER, the less electricity is required for the A/C unit to cool the space. However, with the introduction of SEER2, the numbers on your unit’s label may not appear as impressive as before.

In 2023, the U.S. Department of Energy (DOE) obligated test labs to represent an average use cycle, leading to the increase in minimum efficiency standards and the transition to SEER2. While the new standards are great news for your utility bills and the environment, it can be tricky for dealers to explain the transition from SEER to SEER2 to homeowners.

To make things simpler, a professional can explain that your old unit may have been 10 SEER, and the new one is going to perform better and more efficiently. Alternatively, energy savings calculators can provide ballpark estimates of the savings you can expect.

It’s important to note that while SEER and SEER2 may seem like apples-to-apples comparisons, they are not. The AHRI Directory is updated with SEER2 metrics for system matches, which can provide homeowners with peace of mind and help dealers to close sales more effectively.

As homeowners, we understand that heating and cooling units are a major contributor to our overall utility bills, and that our equipment’s efficiency matters. By taking the time to educate yourself on what to look out for while shopping for new equipment, you can make informed decisions that will benefit both your wallet and the environment.


Adoption of Heat Pump Units.


According to HVAC Informed, the air source heat pump market is expected to grow significantly in the coming years, with an estimated 17 million units to be installed annually by 2028. This growth can be attributed to increased investment in green building infrastructure and technological advancements. In addition, developing countries have implemented strict regulations to limit carbon footprint and introduced favorable policies for the adoption of efficient heating units.

The COVID-19 pandemic impacted the global economy, but the ongoing vaccination drives and easing of lockdown protocols have provided a revival of various industries, leading to an uptrend in commercial application. Air-to-air heat pumps are widely installed in small logistics and transportation establishments due to their low power requirement and simple design.

Commercial air source heat pumps accounted for 25% of the market share in 2020, with growing demand from various sectors like colleges/universities, offices, and government/military services. The North American market accounted for over 33% of the global industry in 2020, with robust development across residential and commercial sectors driving demand.




HVAC Training and Education

The Importance of Monitoring Compressor Discharge Temperature.

The temperature of a compressor's discharge line can be an important factor when troubleshooting refrigeration or air conditioning systems, but it is often overlooked. This temperature is significant because it provides an indication of the amount of heat absorbed in the evaporator and suction line, as well as any heat generated during the compression process.

Because the discharge temperature is superheated, there is no pressure-temperature relationship, and a temperature-measuring device must be used to read it directly from the discharge line. It should be measured about one to two inches away from the compressor and should never exceed 225°F as carbonization and oil breakdown can occur.

There are three primary causes of high discharge temperatures: high condensing temperatures, low evaporator pressures and temperatures, and high compression ratios.

High condensing temperatures occur when the refrigerant changes from a vapor to a liquid in the condenser, and the compressor must compress the refrigerant from the low-side (evaporating) pressure to an elevated high-side (condensing) pressure. This added work can raise the heat of compression, causing the compressor's discharge temperature to be higher.

Dirty condensers, high ambient temperatures, non-condensable air in the system, condenser fan issues, restricted airflow, refrigerant overcharge, wrong refrigerant, and high heat loads on the evaporator are all potential causes of high condensing temperatures. Low evaporator pressures can also cause high compressor discharge temperatures.

When evaporator pressures are low, the compressor must compress the refrigerant from this lower pressure to the condensing temperature. This added work of compression makes the heat of compression higher, resulting in a higher discharge temperature.

Causes of low evaporating pressures and temperatures include dirty or iced-up evaporator coils, evaporator fan motor issues, lack of airflow over the evaporator, frost from high humidity or defrost component malfunction, low heat load on the evaporator coil, defrost intervals set too far apart on the time clock, undercharge of refrigerant, end of the running cycle, partially plugged filter-drier or compressor inlet screen, restricted liquid line, wrong refrigerant, or metering device starvation.

High compression ratios are a result of high condensing pressures or low evaporator pressures, or both. High compression ratios mean there is more work added to the compression stroke of the compressor, causing the heat of compression to increase and the compressor to have a higher discharge temperature. Volumetric efficiency can also play a role in high compression ratios, as a higher volumetric efficiency will introduce more refrigerant into the cylinder with each downstroke of the piston, resulting in more refrigerant circulated with each revolution of the crankshaft.

In conclusion, monitoring the compressor discharge temperature is critical in identifying potential problems in refrigeration or air conditioning systems. By understanding the causes of high discharge temperatures, technicians can quickly troubleshoot and diagnose the underlying issues and prevent further damage to the system.


Making the Decision to Repair or Replace Your Evaporator Coil.

When a refrigeration system experiences a loss of refrigerant, the leak can occur in various locations, but one common spot is the evaporator coil. If this happens, you have to make a decision whether to repair the coil or replace it altogether, and there are pros and cons to both options.

Repairing an evaporator coil can be risky, and it's not always possible. Replacing the coil is expensive, and it might not be feasible to obtain the original one for older models. Another alternative is to replace the entire unit, but it's the most expensive option. Ultimately, the decision will depend on the overall condition of the unit, and what solution is the most reliable and cost-effective long-term.

Before starting any repair, it's crucial to discuss options with the equipment owner to find the best solution. Sometimes, the cheapest repair may not be the most reliable long-term option for their business.

When considering a repair on a coil, there are a few factors to consider. First, where is the leak located? Leaks on a return bend are easier to fix than those close to the tube sheets or within the finned section. Leaks in those locations might be repairable, but they require cutting away the metal. In some cases, repairing the coil might be extremely difficult or impossible.

Second, heat could cause further damage and make the repair impossible or impractical. Evaporator coils have thinner-walled tubing than the ACR tubing, and too much heat could burn through the section being repaired or make the hole larger, rendering the repair impractical.

Third, if repairing the coil is feasible, another leak may develop. This could lead to a second repair or replacement, which could be uncomfortable for the technician and the customer, who may not be happy about paying for another expensive repair after spending money on the first repair.

When replacing an evaporator coil, using an OEM replacement is preferred, but if that's not possible, a similar coil with the same Btu rating, physical size, and configuration might work. Another option is to replace the entire evaporator assembly, which includes the coil, its housing, and fan. Technicians must match the Btu capacity and physical dimensions. Finding a non-OEM replacement can be challenging, but the extra effort required might be a better option than trying to repair the original coil.

Ultimately, it's generally better to replace an evaporator coil than attempt a repair. It's more reliable and the best long-term solution for a customer. Consider discussing the options with the equipment owner and weighing the pros and cons before making a final decision.

Keywords: Compressor, Heat Pumps, SEER and SEER2,  2J newsletter