Distribution & Common Issues

For heated water or steam, piping is used to transport the heat to the rooms. A large number of modern hot water boiler heating systems have a device called circulator, which is a pump, to move hot water through the distribution system (as opposed to older gravity-fed systems). The heat can be transferred to the surrounding air using radiators, hot water coils (hydro-air), or other heat exchangers. The radiators may be mounted on walls or installed within the floor to produce floor heat.

The whole procedure of using water as the heat transfer medium is known as hydroponics. The heated water can also supply an auxiliary heat exchanger to supply hot water for bathing and washing.

In an HVAC system, warm air systems distribute the heated air through ductwork systems of supply and return air through metal or fiberglass ducts. Many systems use the same ducts to distribute air cooled by an evaporator coil for the purpose of air conditioning. The air supply is normally filtered through air cleaners to remove dust and pollen particles.

Common issues:

  • Restricted Or Poor Quality Airflow

Many HVAC users complain that they aren’t receiving adequate ventilation in all areas of their property. If you are experiencing a restriction in airflow, then it could be due to a couple of reasons. One of the most common is clogged air filters. Air filters are designed to trap and collect dust particles and pollutants from your HVAC unit. But once they become overloaded they can limit the amount of air that passes through them, causing the drop in airflow. In order to avoid this issue, filters should be switched out routinely every month.

If the airflow isn’t increased after the filter has been changed, then the problem may have affected internal components too. Evaporator coils that receive insufficient ventilation tend to freeze up and stop working properly. If this problem persists, then the entire unit can suffer. Replacing the filters and defrosting the coil is often the only way to solve this issue.

  • Water Damage And Leaking Ducts

Often building maintenance teams will be called in to deal with overflowing ducts and drain pans. The drain pan is designed to deal with surplus water, but can quickly become overwhelmed if humidity levels are rapidly increased. In most scenarios, this is caused by the melting ice from frozen component parts.


The intense use of furnaces, space heaters, and boilers as a procedure for indoor heating can result in incomplete combustion and the emission of carbon monoxide, nitrogen oxides, formaldehyde, volatile organic compounds, and other combustion byproducts. These are extremely hazardous for the human respiratory system. Incomplete combustion occurs when there is insufficient oxygen; the inputs are fuels containing various contaminants and the outputs are harmful byproducts, most dangerously carbon monoxide.

Sans proper ventilation, carbon monoxide can be lethal at concentrations of 1000 ppm (0.1%). However, at several hundred ppm, carbon monoxide exposure induces headaches, fatigue, nausea, and vomiting. Carbon monoxide binds with hemoglobin in the blood, forming carboxyhemoglobin, and this reduces the blood’s ability to transport oxygen. The primary health concerns associated with carbon monoxide exposure are its cardiovascular and neurobehavioral effects. Carbon monoxide can cause atherosclerosis (the hardening of arteries) and can also trigger heart attacks. Neurologically, carbon monoxide exposure reduces hand to eye coordination, vigilance, and continuous performance. It can also affect time discrimination.

Ventilation can be defined as the process of replacing air in any space to control temperature or remove any mixture of moisture, odors, smoke, heat, dust, airborne bacteria, or carbon dioxide, and to replenish oxygen. Ventilation includes both the exchange of air with the outside as well as circulation of air within the building. It is one of the most important factors for maintaining acceptable indoor air quality in buildings. Methods for ventilating a building may be divided into mechanical/forced and natural types.

In an HVAC, an air conditioning system, or a standalone air conditioner, provides cooling and humidity control for all or part of a building. Air-conditioned buildings often have sealed windows, because open windows would work against the system intended to maintain constant indoor air conditions. Outside, fresh air is generally drawn into the system by a vent into the indoor heat exchanger section, creating positive air pressure. The percentage of return air made up of fresh air can usually be manipulated by adjusting the opening of this tent, which is really quite easy.

Free cooling systems can have very high efficiencies. These are sometimes combined with seasonal thermal energy storage so that the cold of winter can be used for summer air conditioning.