#hvaclife Archives | United CoolAir

January 6, 2020 by Kevin Stepp

Recovering Energy from Class 2 Exhaust Air

The Problem

Providing a healthy environment must be the top priority for any air conditioning design. This can be difficult though, especially in spaces that generate less-than-ideal breathing conditions. Nail salons, health clubs, and bathrooms are just a few examples of spaces where processes or people taint the air with undesirable chemicals or odors. In these spaces, building designers are missing an opportunity to save valuable energy while providing healthy buildings.
ASHRAE 62.1 – 2019 designates air in these spaces as Class 2 air and stipulates that it must be exhausted. Fresh, but expensive to treat, outside air must be brought into the building to replace the exhaust. Here, designers are dropping the ball if they simply throw away the exhaust air. It contains valuable heat energy that should be recovered and used to reduce the energy needed to condition outside air.

The Solution

United CoolAir’s Alpha Aire utilizes two energy recovery devices to extract heat energy from the exhaust and pre-cool (in summer) and pre-heat (in winter) outside air before it reaches a coil. The unit design reduces the load on the cooling and heating coils to as little as 1/3rd that of a standard outside air unit. At a fraction of the operating cost, Alpha Aire delivers room-neutral (roughly 73° and 50% RH), fresh air to a building.
One common concern with Class 2 applications is whether the exhaust air will be transferred back into the building by way of the energy recovery wheel. United CoolAir utilizes a molecular sieve enthalpy wheel with a rated EATR of 0.5% or less. This means that less than one half of one percent of air leaving the building will be trapped in the wheel and recirculated into the space, a rate undetectable to humans and one far lower than the 10% allowed by ASHRAE 62.1 – 2019.
Designers should not hesitate to use all of the energy at their disposal. Alpha Aire gives them the opportunity to do just that. Call or click the link above to find out more.

Applications

Toilet rooms	Nail salons	Museums
Locker rooms	Pet shops	Hotels
Shower rooms	Barber shops	Health clubs
Science labs	Restaurants	Laundry rooms
Libraries	Bars	Pharmacies
Art classrooms	Bowling alleys	Churches

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.

September 13, 2019 by Matt Hanson

All about packaged units in air conditioning

Packaged Unit HVAC

Since the invention of the air conditioner in 1902, engineers have developed various ways of handling the HVAC process. The evaporator and condenser sections are the two major components of Heating, Ventilation and Air Conditioning (HVAC). This is the case as it applies to Direct Expansion (DX) type systems. At the same time, the indoor air absorbs heat inside the evaporator section. The condenser converts the vapor to a liquid by cooling it down. This section is usually located outside on the roof or on the ground. Because the two sections are located in different areas, this is called a split system.

A packaged unit is when the heating and cooling components are contained in the same unit. This type of system can be beneficial when space is minimal. Many times, this type of HVAC unit is also placed outdoor but can also be installed completely indoor. Connected to both the supply and return air ducts; these operate similar to a central air system. These packaged units can be delivered as both air-cooled or water-cooled systems.

The Refrigeration Cycle

In the refrigerant cycle, the air-cooled or water-cooled liquid goes through an expansion valve and is converted into a vapor. The vapor then absorbs heat inside the evaporator before moving on to the compressor. After the compressor, the vapor then goes to the condenser where the refrigerant is air or water-cooled. The component known as a heat exchanger can be accomplished by way of shell and tube, plate and frame or coil.

To achieve the cooling effect, water is supplied continuously to the system. Sometimes building codes do not permit an HVAC system to be installed outside. In this case, packaged units can be installed as a solution. United CoolAir produces these all-indoor packaged systems. By the way, the self-contained HVAC units and are available with multiple air path configurations.

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 installed to control the flow of refrigerant into the evaporator in response to the cooling load. 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.

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June 18, 2019 by Matt Hanson

Commercial vs Residential HVAC Units

Learn the similarites and differences between commercial and residential units

Commercial vs Residential

Commercial and Residential HVAC units share many similarities but contain many differences as well. While some HVAC manufacturing companies produce units for both markets, others specialize in one or the other. The biggest differences have to do with size, and whether the unit is packaged or split. Commercial systems are typically modular in nature, which makes them more flexible and expandable. These units are for business applications and can serve very large office buildings to small shops.

Many times the HVAC unit is installed when the building is first being constructed presenting a problem later. Eventually the unit will be in need of replacement. Commercial units because of their size and complexity usually require more highly trained technicians to install and service the equipment. This type of HVAC unit is designed to serve multiple zones and is capable of providing heating as well as cooling to the building. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) sets Minimum Ventilation Rates in Breathing Zone standards as to how much fresh air must be delivered for the number of occupants in a given room. HVAC units are measured in tonnage or CFM (Cubic Feet per Minute), while ASHRAE advises 20 CFM per person in a health club, only 5 CFM per person is recommended for a library.

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