#hvacquality 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

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.

August 30, 2019 by Matt Hanson

What is a Heat Pump and how does it work?

Heat pump

A heat pump represents a growing segment of the HVAC industry. In practical terms, it is a reversal of how the air conditioning system works. Where air conditioners are used for cooling air, a heat pump can be used for cooling or heating if is used in the right conditions. Therefore, it is necessary to employ a heat pump where temperatures are more moderate. The Mid-south is one such area where the unit can be used for cooling in the Summer months and be converted into a heating application when the temps are a bit cooler. In areas such as Florida or California where temperatures are mostly warm, it is best to use an air conditioner only.
Heat pumps use a reverse refrigeration cycle as opposed to the regular vapor compression cycle of an ac unit. Heat pumps use the condenser section to generate heat whereas an air conditioner uses it to reject heat. A heat pump uses a small amount of energy to move heat from one location to another and can be reversed to cool a building or office space. Air conditioners and heat pumps work in a very similar way. The biggest advantage to a heat pump is there is no need to have separate units to handle heating and cooling. Since the heat pump is only transferring heat it can operate by electricity and does not rely on the burning of fuel to accomplish the process.
In the cooler months, a reversing valve reroutes the refrigerant path making the outdoor condensing coil function as the evaporator and the indoor coil as the condenser. The outdoor heat is absorbed by the evaporator and then used by the condenser to heat the indoor space. However, there is one remaining problem. Now that the evaporator is outside and is tasked with absorbing heat it must operate at temperatures lower than the outside air. This low operating temperature causes ice to build-up on the outside of the evaporator. Consequently, the unit must go through a defrost cycle where auxiliary heat must be used to provide indoor heat during this stage.

May 24, 2019 by Matt Hanson

Sick Building Syndrome and what to do about it

Sick building syndrome, sometimes referred to as tight building syndrome is a term that was developed from the ill effects building occupants incur because of poor indoor air quality. Although there is not one specific disease that is solely attributed to (SBS). Ill health and loss of employee productivity is a major concern of poor indoor air quality.

Sick Building Syndrome