HVAC systems come in many shapes and sizes. Some may only heat or cool but many will carry out both functions. Regardless of the system type or functionality, they are all designed to achieve the same goal - transferring heat to, or from, the treated space. 


1. Split Type (Mini-Split)

split system is a particular type of air conditioner with a separate condenser located outside and an evaporative coil located indoors. Rather than using ductwork to transfer air, the two parts of the system are connected by copper pipes transferring refrigerant. 


2. Furnace

Modern furnaces run off gas, electricity, or induction. Contemporary high-efficiency systems also utilize both heating and cooling components to offer increased control over your HVAC system. The days of a pure gas furnace are mostly over now. 


Smaller furnaces may also be attached to hot water boilers to apply supplementary energy or heat transfer, often referred to as heat exchange. Using up or transferring as much potential energy into the home's boiler or hot water tank results in increased energy efficiency and reduced costs.


3. Rooftop Unit (RTU)

Typically found in commercial or dense residential applications, a rooftop HVAC unit, or RTU, is a fully packaged self-contained HVAC system. At a minimum, the evaporator, condenser, fan motor, and compressor are all located within this enclosed unit. Additional accessories such as heat exchangers, re-heaters, and humidity controls may also be located within the housing. As the name suggests, these systems are generally installed on top of a roof but they can also be installed at ground level and ducted into buildings where there is no suitable or level space on a roof.

Sometimes RTUs may be referred to as an Air Handling Unit (AHU). These two systems tend to be virtually identical. 



Another variation on rooftop units is the Make-Up Air (MAU). This type of HVAC solution pulls in fresh, tempered air from outside your building to replace existing air that cannot be recirculated. A common application of this is increasing ventilation (making-up air) in large commercial kitchens. These systems do not condition air to the level a fully kitted-out RTU would.


4. Packaged Terminal Air Conditioner (PTAC) 

Packaged Terminal Air Conditioner (often abbreviated as PTAC) is a type of self-contained heating and air conditioning system commonly found in hotels and apartment blocks. They have also been colloquially referred to as "window-shakers" as they often sit at or in window openings.



5. Heat Recovery Ventilators (HRV) / Energy Recovery Ventilators (ERV)

Heat recovery ventilators (HRV) and energy recovery ventilators (ERV) are air exchange systems that help to enhance indoor air quality and minimize heating costs. They retain existing heat and optimize the interior moisture content in the air. These mechanical systems use fans to maintain a balanced airflow into the house while exhausting stale indoor air.


In summary, HVAC systems come in different shapes and sizes but they all have the same goal:  transferring heat to or from a treated space. 


Don't see your home's system here or are unsure if it's compatible? Check out our system compatibility guide here.


If you don't already have HAVEN products installed, speak to your HVAC contractor today about adopting HAVEN products to control your air.

    • They can reach out to us at for more information. 
    • We'll help them find the best solution to resolving any IAQ concerns you may have.



      If you have any questions about our HAVEN IAQ products, our dedicated Support Team can be contacted directly via 1-888-964-2836 or





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