#hvac #hvaclife #plumbing #hvactechnician #airconditioning #heating #hvactech Archives

March 17, 2022 by Matt Hanson

Commercial vs Residential HVAC

While the commercial and residential HVAC industries have similarities there are differences as well. No matter what type of HVAC being deployed, the purpose always comes down to cooling, heating, dehumidification, and ventilation. Some of the key differences involve size, location and manufacturing. While there are HVAC manufacturers that specialize in one or the other, some companies are more specialized. Whichever industry is in question there are key things to know about when it comes to commercial vs residential HVAC.

Residential HVAC

Residential HVAC systems are what cools and heats homes and small businesses. Fundamentally, these systems operate the same as commercial units. These unit are often split between the evaporator and condenser section and located outdoors beside the home. Other times the location is an attic or crawl space. These use of these types of units is most heavily in the Summer and Winter months.

The residential market accounts for roughly 40 percent of the HVAC market. Furthermore, servicing these units occurs by a single contractor. Residential units are usually smaller than commercial units and are easier to service. As a repair technician there is much more contact with the owner of the unit than with commercial.

Commercial HVAC

Commercial HVAC systems have the same functions as residential but are instead, installed in corporate and industrial buildings of all sizes. These units are very large and located on rooftops but there are also modular packaged units that are installed indoors. These units usually involve contractors and architects in the planning phase. Some industries using commercial units include manufacturing, healthcare, education, offices, churches, restaurants, retail stores, banks, and hotels. Commercial units are more complex and costly than residential and require a higher skill level to install and maintain. They account for up to 60% of the HVAC market.

Summary

Whether residential or commercial, HVAC units will continue to innovate to meet the cooling and heating needs of both markets. New efficiency requirements and coolant types are ever evolving. The following resources have updated information on the HVAC industry.

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE)
HVAC Excellence
North American Technician Excellence (NATE)
Refrigerating Engineers and Technicians Association (RETA)
Refrigeration Service Engineers Society (RSES)

February 22, 2021 by Matt Hanson

Improving Indoor Air Quality in Commercial Buildings

Indoor Air Quality

Indoor air can be considerably more detrimental to people’s health than outside air. With this in mind, it is important to identify where indoor air contaminants originate and address the possible health effects. To begin with, we can improve indoor air quality

Particulate matter
Carbon Monoxide
Secondhand tobacco smoke
Pesticides
Solvents
Volatile organic compounds
Biological pollutants
- Mites
- Allergens
- Molds
Built environment
Radon
Asbestos
Occupation-related contaminants

Schools present an extraordinarily important focus due to the unique vulnerability of children. This is because children inhale more pollutants per kilogram of body weight than adults. Furthermore, with children having narrower airways, indoor pollutants can result in proportionately greater obstruction to airways.

Particle Size

Pollutants travel through the air by multiple means. For instance, particles come in an array of sizes ranging from coarse particles (2.5–10) to fine particles of less than 2.5 micrometers. In particular, the size of particles is a determining factor in which part of the lung receives particle deposits. For this reason, children may be greater affected by the smallest of particles according to the World Health Organization (WHO). Furthermore, children that reside in urban areas are at greater risk of IAQ due to spending more time indoors than rural children.

Sometimes the negative impact of indoor air quality is caused by the burning of fossil fuels and poor ventilation. Yet other times poor air quality is associated with building materials such as asbestos, formaldehyde, paints, glues, resins, spray propellants, and cleaning agents.

Acute and Chronic effects of air pollutants

Poor indoor air quality can affect people in a variety of ways from mild to severe.

Acute:

Irritation of mucus membranes (eyes, nose, and throat)
Cough, wheeze, and chest tightness
Increased airway responsiveness to allergens
Increased incidence of acute respiratory illness:
Tracheobronchitis
Exacerbation of asthma

Chronic

Long-term exposure decreases lung growth
Impairment of pulmonary function
Increased susceptibility to chronic obstructive lung diseases
Other

Prevention is the key
Carbon Monoxide (CO) is a colorless, odorless gas formed by the incomplete burning of carbon-based fuels. Exposure to this gas can lead to intoxication that results in tissue hypoxia. Breathing high levels of carbon monoxide can lead to symptoms such as headaches, dizziness, and weakness. Breathing even low levels can cause fatigue and increase chest pain in people with chronic heart disease. Smoke and CO detectors may provide early warning and prevent exposure.

Tips:

Keep fuel-burning appliances in good working condition
Check heating systems, chimneys, and vents on a regular basis
Never burn charcoal indoors
Never leave a car running in a closed garage.
Consider CO detectors

Ventilation is Paramount

Finally, one of the best ways to improve indoor air quality is to bring clean fresh air into the building. Of course, this is easily accomplished by the use of a dedicated outdoor air system (DOAS). These units work in conjunction with an HVAC unit to bring in fresh room neutral air which also saves energy by helping the HVAC unit run more efficiently. Besides, United CoolAir makes several packaged DOAS units in various tonnages.

February 7, 2019 by Matt Hanson

HVAC Replacement Made Better

What if there was a way to replace existing indoor HVAC equipment that has reached its lifespan. Furthermore, without expensive demolition and alterations to the building structure?
Many contractors, engineers, and property managers try to answer this question each day. It’s a question that is seemingly easy to answer. The dismantling of Outdated equipment could help make the debris more easily hauled away to make way for a replacement unit. The problem is that most replacement units are too large to bring into spaces without major disruption and structure modifications.

There is a better way of HVAC Replacement

United CoolAir equipment is a better solution for replacement HVAC units. Our units are modular in construction with quick connects and re-sealable fittings that allow replacing equipment without demolition. Most UCA units can fit through a standard doorway or elevator, around tight corners of hallways and into the space. The process of installing United CoolAir units can save time and money leading to greater satisfaction in the retrofit process.

Countless numbers of HVAC units were installed while the building was under construction thus confining the unit in its chosen location. The current protocol is to chop up a brand new unit and bring it into spaces and then reassemble the equipment. The alternative is to knock down a wall or removing part of the roof in order to accomplish the replacement task. The problem with both of these solutions is the damage that can result in new equipment and the expense of building demolition and reconstruction. These building alterations can add tens of thousands of dollars to the total replacement cost.

Do all commercial HVAC units have to be installed outdoors?

No, companies such as United CoolAir produce HVAC units that are installed completely indoors.

Is there such a thing as an indoor DOAS unit?

Yes, United CoolAir produces several dedicated outside air units that are installed completely indoors.

September 28, 2018 by Matt Hanson

Emergency Temporary Portable Cooling and Heating

Emergency temporary cooling, heating units

When tragedy strikes in the form of natural disasters such as hurricanes, tornadoes, and other extreme weather events, time, and resources are of the essence. Without reliable temporary cooling and heating systems, critical infrastructure can fail. This results in important social services such as hospitals and other institutions being unable to function as well as data loss. Moreover, the housing of evacuees requires large populations to locate into tents or makeshift shelters, and having appropriate systems can save lives. Unfortunately, AC units sold on the retail market lack the power to provide adequate relief to a large space or populace. This is because retail units only go up to 14,000 BTUs. Therefore, it is imperative to have mobile, rugged, and powerful systems that can reach up to 360,000 BTUs, such as Untitled Cool Air’s units. In addition, larger units are in development.

Built to last Commercial Units

Emergency units must be tough and hold up under harsh conditions and transport. Instead of cabinets built out of flimsy plastic, you will need a unit constructed from thick metal and quality parts. During the construction of United CoolAir portable units, they tested before leaving the factory. This line of portable units is self-contained and built with various capacities and sizes. Units are also provided as air-cooled, water-cooled, and heat pumps. The production of these well-constructed reliable units started in 1988, in York, PA.

For indoor or outdoor applications, these horizontal units are small and flexible. But also when operating indoors, the condenser air can be ducted outside. A low-profile design provides a neat, clean appearance. Mobility is paramount for these portable air conditioning units. They can be provided with an integral unit-mounted forklift pod or with casters. The ducted feature makes these units ideal for temporary cooling or heating in renovation projects. Other applications include spot cooling or heating and temporary cooling when the building air conditioner is down for maintenance. Other uses include providing extra cooling or heating when needed to augment the building system. These portables can supply cooling only or cooling and heating options. On the other hand, the design of these units for your specific requirements covers a wide variety of options.

August 31, 2018 by Matt Hanson

Dedicated Outside Air Systems (DOAS) part 2

Adapting DOAS To Your HVAC System

There is a proven method that will meet the challenges of complying with the ASHRAE Standards. This method delivers precise amounts of ventilation to spaces regardless of load size, and do it cost-effectively. Known specifically as Dedicated Outside Air Systems, or (DOAS), the conditioned outdoor air separates from the air that controls the building’s space temperature (dry bulb). By having separate systems providing dehumidified and ventilation air and another for dry bulb temperature, there is an improvement of both humidity and space temperature control. By conditioning the outdoor air and recirculated air independently, Dedicated Outside Air Units effectively separates the sensible and latent loads.

The DOAS unit removes the latent load to control humidity, while the main HVAC unit removes the sensible load. The result is a comfortable temperature for the space occupants. This is important because the primary source of building humidity in most climate areas is fresh outdoor ventilation air is improper dehumidification. Additionally, the DOAS unit can assist the main HVAC unit by controlling smaller internally generated amounts of latent load. This latent load naturally builds from occupants and other sources. It does this by providing air that is slightly drier than the target humidity level. Generally speaking, a Dedicated outside air unit provides a “neutral” air of 70ºF to 72ºF @ 50% RH.

What About Dehumidification

A DOAS unit can also provide the dehumidified air directly to spaces at 55°F where it will offset some of the sensible load of the local HVAC unit. By delivering the air “cold”, this operation strategy doesn’t waste the sensible cooling byproduct performed by dehumidification. This results in the local heating/cooling units sized smaller and require less valuable floor space. A smaller main heating/cooling system means less energy consumption through smaller fans and compressors. A DOAS delivering cold supply air requires less reheat, but some reheat could happen during periods of low sensible loads. In this way, there is not “over-cooling” by the DOAS unit.

A DOAS doesn’t rely on new technology but rather uses HVAC equipment configured to condition outdoor ventilation air separately from return air. The outside air conditioning system design consists of a cooling/dehumidification-reheat coil and a supplemental heating system. The deep evaporator coils consist of 10 fins per inch/6 rows deep design, positioned in the draw- through airflow arrangement. It is this technique that differentiates it from conventional HVAC systems. This configuration will cool and dehumidify air in the summer and heat or cool it in the winter. The design with outdoor air first passing through an optional preheat coil (if used), is sometimes used for winter operation. By using a heat exchanger, bringing the outdoor air closer to the temperature and humidity of the conditioned exhaust air is achieved.

Dedicated outside air units provide design engineers with installation flexibility to meet the requirements of the application. Variables facing the engineer include; new construction, retrofit, or installations having an existing system in place. Other considerations include the type of new or existing HVAC system installed such as constant volume, VAV, and even the newer variable refrigeration flow (VRF) terminal units.

All About Ducting a DOAS

Delivering the conditioned OA from the DOAS to where it’s needed usually includes a separate ducting system. This system runs parallel to the HVAC supply air. For many climates, an independent duct system is the best choice because the ventilation air volume better meets the volume requirements of the project. Furthermore, the DOAS ducting can be smaller than the conventional HVAC saving on the installation cost. Smaller ducting is also easier to manage in retrofit and existing HVAC installations.

A popular alternative ducting choice is a single duct system where the conditioned OA is blended with return air from the main HVAC system. For this, we use a mixing box, or in a terminal unit that serves just one zone. If using a multi-zoned HVAC control system, individual zones are controllable separately. In this way, the DOAS will deliver the proper amount of outdoor air directly to each zone. In all cases, the DOAS can vary the fraction of ventilation to supply air, which can reduce the outdoor airflow rate by 40 percent. This is due to only conditioning the amount of air necessary for each zone.