We’ve lived our entire lives, and continue to work in Southern Maryland and parts of Virginia, and are committed to the local community. Both the loyalty of our long-term customers and our A+ BBB rating are a testament to our dedication. Exceeding your expectations for service and performance, T. N. Bowes Heating & Air Conditioning, Inc. delivers the results you’re looking for.
Air conditioners come in two basic types—central and window. A central AC provides cooling to your entire home, while a window AC cools just the room where it’s installed. If you’re not using a heat pump, you can pair an air conditioner with a furnace to provide both heating and cooling. Just to make things a bit more confusing, a central air conditioner housed together with a furnace in a single cabinet is also known as a packaged unit!
Electronically Commutated (EC) fans use brushless DC motors which include in-built electronics to convert the AC supply to DC without the need for a separate DC supply. EC fans provide a more efficient (up to 30%) means of airflow through Precision Air Conditioning (PAC) units with the additional benefit of variable speed control via an output signal from the unit controller. Also see EC Fan upgrades.
We take great pride in our crew, choosing the best and brightest to represent R.S. Andrews in the face of an emergency. Our HVAC contractors boast not only unparalleled skill but also a friendly and professional demeanor. All of our work comes completely guaranteed, and we won’t rest until your emergency has been resolved to your full satisfaction!
Heat pumps are similar to cooling only systems with one exception. A special valve in the refrigeration piping allow the refrigeration cycle to be operated in reverse. A cooling only system cools the indoor air and rejects heat to the outdoors. A heat pump can also cool the indoor air, but when the valve is reversed, the indoor air is heated. A supplementary electric resistance heater may also be used to assist the heat pump at lower outdoor temperatures. In colder climates, heat pumps require a defrost period. During defrost times the electric heater is the only means of heating the interior of the building. These units are manufactured as either split or packaged systems.
All modern air conditioning systems, even small window package units, are equipped with internal air filters. These are generally of a lightweight gauzy material, and must be replaced or washed as conditions warrant. For example, a building in a high dust environment, or a home with furry pets, will need to have the filters changed more often than buildings without these dirt loads. Failure to replace these filters as needed will contribute to a lower heat exchange rate, resulting in wasted energy, shortened equipment life, and higher energy bills; low air flow can result in iced-over evaporator coils, which can completely stop air flow. Additionally, very dirty or plugged filters can cause overheating during a heating cycle, and can result in damage to the system or even fire.
"I was experiencing problems with one of my rooms not getting enough air flow, I was reached out to and they got a better feel for what my situation was and gave me the best honest opinion about what I should do, I really appreciate their professionalism in the manner and not just trying to gain my business. They really looked out for me as a customer, and I couldn’t be more grateful!"

In 1906, Stuart W. Cramer of Charlotte was exploring ways to add moisture to the air in his textile mill. Cramer coined the term "air conditioning", using it in a patent claim he filed that year as an analogue to "water conditioning", then a well-known process for making textiles easier to process. He combined moisture with ventilation to "condition" and change the air in the factories, controlling the humidity so necessary in textile plants. Willis Carrier adopted the term and incorporated it into the name of his company.[10]
Heat pumps are similar to cooling only systems with one exception. A special valve in the refrigeration piping allow the refrigeration cycle to be operated in reverse. A cooling only system cools the indoor air and rejects heat to the outdoors. A heat pump can also cool the indoor air, but when the valve is reversed, the indoor air is heated. A supplementary electric resistance heater may also be used to assist the heat pump at lower outdoor temperatures. In colder climates, heat pumps require a defrost period. During defrost times the electric heater is the only means of heating the interior of the building. These units are manufactured as either split or packaged systems.
Welzig Heating & Air is on call, 24 hours a day, 365 days, making sure that the skilled assistance you need is always available.   There’s no need to struggle with decreased performance from your air conditioner.   Even small aggravations, such as elevated sound levels, strange smells, or longer running times, are warning signs of larger issues and usually add up to higher running costs.   When you trust your cooling equipment to Welzig Heating & Air, we work to not only resolve pressing issues. but ensure reliability, efficiency, and longevity.   A thorough inspection often protects against degraded air quality, property damage, and premature system failure.   We work on all makes and models of air conditioners, and with every repair we tackle, our team of dedicated technicians earn your satisfaction.   Through exemplary customer service, ethical business practices, and exacting standards, Welzig Heating & Air provides superior solutions to homeowners across Boulder, Longmont, Louisville, Lafayette, CO & more.

Inside the unit, the air passes over the evaporator coil first, and is cooled and dehumidified. The now dehumidified, cold air then passes over the condenser coil where it is warmed up again. Then the air is released back into the room. The unit produces warm, dehumidified air and can usually be placed freely in the environment (room) that is to be conditioned.


The compressor-based refrigerant systems are air-cooled, meaning they use air to exchange heat, in the same way as a car radiator or typical household air conditioner does. Such a system dehumidifies the air as it cools it. It collects water condensed from the cooled air and produces hot air which must be vented outside the cooled area; doing so transfers heat from the air in the cooled area to the outside air.
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In the refrigeration cycle, heat is transported from a colder location to a hotter area. As heat would naturally flow in the opposite direction, work is required to achieve this. A refrigerator is an example of such a system, as it transports the heat out of the interior and into its environment. The refrigerant is used as the medium which absorbs and removes heat from the space to be cooled and subsequently ejects that heat elsewhere.
No one wants to be stuck in the dead of summer with a broken air conditioner, or in the cold of winter with a broken furnace or boiler. That’s why we’re available any time of day to make your emergency heating and air conditioning repair and get your system up and running as quickly as possible. We’ll show up on time, in uniform and ready to make your HVAC repair right the first time.

Have your contractor do a load calculation based on a recognized method, such as one in Manual J from the ACCA. The contractor’s evaluation should include whether your ducts need to be resized, sealed and insulated, or replaced. Remember that an indoor evaporator coil and outdoor condenser must be a matched set from the same brand, or the performance, efficiency, and capacity might not meet expectations.

If you are installing an AC system from scratch, your contractor should calculate the size of the cooling equipment you need by using recognized methods such as what you’ll find in the Residential Load Calculation Manual, aka Manual J, from the Air Conditioning Contractors of America (ACCA). If you already have ductwork for your heating, adding a central system can cost less.
Sometimes a heating and air conditioning system just needs to be repaired rather than completely replaced. You may need air conditioning repair services if there is leaking around the outside unit, the air coming into the house isn't hot or cool enough, the unit is short-cycling or constantly turning on and off, using the system is consistently resulting in higher-than-normal energy bills, or if there is excessive noise during startup and operation.
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