#hvacr Archives | United CoolAir

October 14, 2020 by Matt Hanson

Compressor Failure and the Effects on Warranty

Identifying why compressor failure is subject to many variables and is important to understanding warranty implications. Although compressors fail for a multitude of reasons, poor installation and maintenance are the most common causes. However, for the vast majority of compressors returned for claims, rarely is it due to a defect in the manufacturer supplied part.

Determining why a compressor has failed is a challenge for contractors of light commercial cooling systems. The mere fact that installation and maintenance procedures are key factors means that most compressor failures are preventable. Therefore, it is of the utmost importance to understand the various ways in which these failures occur.

Following OEM guidelines for installation, startup and service are critical for installers of both ducted and ductless systems. For instance, the act of completing a compressor changeout can introduce contaminants to an HVAC system. Conversely, there is the rare occurrence of natural causes such as lightning or line voltage fluctuations that happen. On the other hand, proper routine maintenance improves the long-term reliability of the system.

This allows technicians to identify issues before they can cause a catastrophic failure. For instance, a dirty outdoor unit coil will result in the inability to reject heat, thus increasing compressor operating temperatures. When this happens, the compressor forces more expended energy while providing less capacity. Therefore, regular routine maintenance is key to keeping a system running well and avoiding compressor breakdown.

Other factors that affect compressor life

When it comes to compressor endurance, keeping refrigerant lines free of moisture or oxidization is very important. When refrigerant lines become contaminated it causes the internal lubricant to become acidic, which can eat away at internal windings.

Another factor contributing to compressor failure is incorrect refrigerant line sizing. When this occurs, it affects pressurization and evacuation to ensure the absence of leaks. It is also important to have correct minimum unit clearance and refrigerant charging procedures. These factors are critical to longevity and the life expectancy of the compressor.

Overheating is yet another variable that causes compressors to lose their operating capabilities. This usually happens when there is not enough refrigerant in the system. When overheating happens over an extended period it will cause the breakdown of winding insulation. Symptoms of overheating may include compressor short cycling due to increased trips on protection devices. This reduces heating and/or cooling performance, and an increases current draw.

Training and Startup Procedures

Contractors can help mitigate the chances of compressor failure by adhering to each manufacture’s startup procedure. This is because each manufacture has unique steps that must transpire in order to keep equipment running smoothly. Finally, attending a manufacturer training session is a good step in achieving longevity in HVAC systems.

February 19, 2020 by Matt Hanson

Replacing a self-contained water-cooled air conditioner

A business owner in Vero Beach, Florida had just bought a building to produce his radio and TV shows. He thought the purchase of the building and the renovation to follow would be the end of his cost. This turned out to be only the beginning of his ordeal. As it turns out, this was an older building and the AC units were about to fail. He made calls to several HVAC companies but each company gave him the same awful news. Although the price of each self-contained unit was affordable, he was looking at several thousands of dollars in additional fees. The extra cost involved tearing down walls and rebuilding them afterwards in order to bring in the new AC units.

The owner seemed shocked to find that this was a usual practice in the industry. In fact, several decades ago self-contained water-cooled unitary devices were installed in mechanical rooms while the building was under construction. Most of these units are enclosed behind walls and replacing them is a major challenge. Surprisingly, although the outdated units could be disassembled and removed, bringing in new units was a nearly impossible. Thankfully, the owner found United CoolAir. We offered him a water-cooled self-contained unit that breaks down into small sections. This enabled them to move units into the space without making modifications to the building. The reassembly went smooth and easy and left this owner without the headaches typical to these types of installations.

Replacing Unitary Systems

Thousands of similar installations exist across the country. United CoolAir has been replacing these units for years with our modular EZ-Fit product. Now, we offer the Renovator, another modular, water cooled, self-contained unit. The Renovator is designed specifically to replace Trane^® SWUD units, the most common self-contained system in existing buildings. Our unit matches the exact footprint and features list of the Trane^® SWUD using smaller modules than a Trane^® equivalent. Additionally, the Renovator features a modular design that allows swift installations of a fully charged and tested unit, all without making costly alterations to the building. Call United CoolAir today or click on the General Inquiry form in the Contact tab above, to see how United CoolAir can save you money on your next replacement project.

October 25, 2019 by Matt Hanson

Industrial Grow Room Units

As cannabis becomes legalized or decriminalized throughout the United States, Grow Room units are in high demand. Medical applications of the plant alone have led to further community acceptance and therefore more facilities have emerged for growth and distribution. In order for this up-and-coming industry to thrive, HVAC companies have developed specialized equipment that promotes indoor plant growth.

Growing cannabis indoors on a massive scale is an elaborate process. To start with, optimal growth conditions require stable temperatures both day and night. When the plants are in the early stages of development they need oxygen-rich air for vigorous growth. Grow room unit development leads to the control of both temperature and humidity in the various stages of plant growth. In particular, the heat stress on developing plants can quickly ruin a crop.

The two-stage humidity problem

When the humidity levels rise too high, conditions become such that mold can develop. Likewise, when levels of humidity fall too low this can add additional stress to the plants. The cannabis plants thrive best when relative humidity is kept within a manageable range.

Grow Room Units by United CoolAir

When it comes to Dedicated Indoor Agricultural System (DIAS) AKA, Grow Room units, United CoolAir is on the cutting edge. Starting in the Spring of 2018 we began producing equipment for Cultiva Systems. This is a complete system unlike the conventional approach that utilizes a standard air conditioner to control temperature and a separate dehumidifier to control humidity. The DIAS has the required capacity for late flower loads and enough turn down to maintain conditions during the earliest stages of the plant. Powerful moisture removal capability and full condensing modulating hot gas reheat keep the room conditions on target. Integral controls and advanced components maximize energy efficiency while achieving the desired conditions; therefore, lowering the operating cost to the grower. Furthermore, these units range from 10 – 45 tons and come in both horizontal and vertical configurations.

October 18, 2019 by Matt Hanson

Retrofitting Commercial HVAC Units

Retrofitting Major Commercial HVAC Brands

Millions of HVAC systems are reaching replacement age. The life cycle for most will pass several times over the life of commercial, industrial and institutional structures. Estimates show that there are over 5 million buildings available for retrofit HVAC upgrades. While 70% of commercial buildings built prior to 1980 have not had any HVAC improvements. With changes in building codes, government regulations, technology, IAQ and environmental standards many building owners face a plethora of challenges.
One of the issues that building owners have little control over is the cost of energy. Current rates range from 6.5 cents to over 12 cents dependent on region. All forecasts show great increases over the next few decades. Considering that 40% of building power cost use is HVAC related, gaining efficiency and cost savings are vital for owners.

Why The Difficulty in Replacing Outdated Units

When initially installing HVAC systems, size, weight, ease of installation and refrigerant there were of no concern. During construction, large chillers were lowered into basements, and rooftop units were installed using machinery already onsite. Now twenty to thirty years later things are more difficult. No longer is there open access or a crane onsite to simplify improvising an HVAC system. Brands of HVAC units reaching the end of life include Trane^® SWUD units, Bohn HVAC Systems, Blazer units, McQuay^® HVAC, Mammoth^® v cube and Carrier^® AC units.

Going Green is the Future

In order to make energy cleaner, greener and more efficient, governments are constantly developing new refrigerant liquids. Many of today’s HVAC units are using the less efficient R22 refrigerant and are therefore in need of replacement. Newer units are using R410a refrigerant but even this will soon be outdated as well. With an emphasis on green buildings, what is the best solution? Buy a replacement rooftop unit and spend thousands of dollars on installation. Installation could cost half of the cost of the replacement unit. How do you remove and retrofit large tonnage chillers from a basement in a dense urban area?

There is a Solution

Keeping this in mind, there are products to solve these retrofit problems. Selecting an off the shelf or stock unit will not be a perfect fit like the initial installations. United CoolAir modifies units to make retrofit projects simple and easy to install. Choosing a splittable system that can move through a standard 32-inch doorway into a standard elevator, resolves to get the units inside an existing structure. This will also lessen the total cost of installation by using less manpower; overcome other technical issues that would be necessary for the installation of standard commercial units. What can make these EZ Fit units even more appealing is they can fit above the ceiling or in a mechanical room? By bringing your units indoors you can gain valuable roof space for green projects such as solar panels or a living roof.

In Conclusion

Additionally, repairs can be made anytime indoors, support longer unit life; eliminate damages from storms, vandalism or even theft of valuable copper destroying your units. Owners can expect a shorter return on investment, lower energy costs, and an overall lower lifecycle cost. Complaints from building owners vary from too costly, tenant interruption, no funding, and others. In today’s climate, governments along with others are providing programs to lessen the financial burden.

PACE bonds, leasing, and energy programs like Potomac Edison provide fantastic incentives to become more energy efficient. Potomac ED’s program provides up to 50% rebate of the purchase price, excluding taxes for each VFD installed capped at a total of $250,000. These programs give building owners every reason to retrofit their obsolete HVAC systems. Besides repair or retrofit is going to become more widespread than new construction in the upcoming years. Lastly, retrofitting your old high energy-consuming system with a unique feature split unit can make a retrofit project as simple as screwing in a light bulb.

July 3, 2019 by Matt Hanson

The Thermal Expansion Valve (TXV) Explained

What you need to know about refrigerant flow

The Thermal Expansion Valve (TXV) is an important piece of equipment in the HVAC industry. The valve is used to control the amount of refrigerant released to the evaporator section. In this way it controls the difference between superheat and the current refrigerant temperature at the evaporator outlet. Therefore, This in turn keeps its saturation temperature at the current evaporating pressure stable. The Thermal Expansion Valve function is the control the flow of refrigerant into the evaporator in response to the cooling load. Additionally, TXV’s measure the superheat at the outlet and react to this by increasing or decreasing the amount of refrigerant flowing into the evaporator to try and maintain a constant superheat.