HVAC Scenting Machines & HVAC Scent Diffusers
Professional HVAC Scenting Systems for powerful scent distribution
throughout the whole home, large residential areas, or commercial spaces
The Benefits of Cold Air HVAC Scenting Systems
HVAC scenting provides an even distribution of scent in your entire home.
All Aroma Designers’ HVAC scenting diffusers are based on waterless cold air diffusion technology which transforms liquid (fragrance oil) into nanoparticles that dissipate into the air as fine aroma mist. One of the inherent benefits of cold air diffusion compared to commonly found aroma humidifiers is no heating or adding water to trigger the misting process. The main benefit of cold air diffusion is the coefficient of efficiency in the transformation process.
HVAC compatible scent diffusers have an internal air pump that creates pressure and picks up the aroma molecules in the form of aroma mist.
Professional HVAC scent machines. Easy installation step by step.
Experience outstanding fragrance scent delivered through your central heating and cooling system. Each HVAC scent diffuser comes with a metal push-in fitting that screws into the machine and a plastic tube that connects the diffuser to the HVAC air duct.

Step 1
In order for the aroma mist to carry through the air duct, the AC must be operating or the blower fan must be turned on. If the AC (or fan) is off, the aroma mist will stay in the air duct and won’t reach the intended space. If the diffuser is operating for a prolonged period of time with the AC fan being off there will be unwanted scent buildup in air ducts and could cause diffuser or air handler damage.
Step 2
HVAC setup typically requires intensity levels 10% to 15% higher compared to standalone diffuser setup. Air duct passage creates an additional volume of space through which the aroma must travel and some capacity is lost due to the extended volume of space. With a standalone setup, the aroma covers a smaller volume of space and has a slower transit time.
Step 3
Installing the air diffuser requires adequate space to accommodate your aroma diffuser and must be close to the air ducts. The ideal placement of the diffuser tube opening is after the air handler and before the first air register (please refer to the diagram above). Please ensure the air duct opening is further away from the air handler body to prevent possible interference.
Step 4
The plastic tube that connects the diffuser with the air duct should be kept as short as possible and at the near-vertical pitch. Avoid ‘sagging’ formations in the tube as this could cause oil accumulation in the lower part of the tube and possibly damage your diffuser.
Step 5
The diffuser plastic tube entering the air duct should be approximately three to four inches inside the duct and pitched at about 10% downward angle just to ease the aroma flow.
Step 6
Ensure proper insulation of the opening by using aluminum tape and secure the plastic tube to one of the hard areas to minimize any tube movement.
Step 7
The placement of the diffuser should be in a dry, clean, moist free environment
nearby a proper 110V power outlet.
Actual HVAC Customer Installations
Frequently Asked Questions
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HVAC Connection
No! Not recommended to place aroma diffusers in the attic space if the temperature is not controlled. Extreme variations in temperature will cause changes in oil viscosity, which it terms affect the misting process. Hot temperatures could make the oil too liquidly and cause oil spills. Cold temperatures could make the oil too dense and not atomize at all.
Connecting the aroma diffuser to your HVAC thermostat for automatic control is possible and should be done by a licensed professional only. In principle, this approach entails having a power relay switch (sold separately in Home Depot and electronic stores) being triggered by the thermostat and on/off cycle the 110V source of the aroma diffuser.
Leveraging the thermostat control for On/Off cycles ensures 100% synchronization between your HVAC and aroma diffuser and negates the need to have the air handler fan On all the time. Some companies have attempted to use the pressure switch approach, but based on our observations thermostat connection control has superior accuracy. The pressure switch approach is prone to false-positive/negative as precise pressure calibration in the air ducts is often not possible.
You can watch how to connect your Aroma Designers scent machine with your HVAC.
Learn more information about HVAC scenting.
Please, check the connection between the plastic tube coming from the diffuser and your HVAC, the connection should be snug and properly sealed.
Our diffusers transform the fragrance oils into nano-particles that can travel effortlessly throughout the air ducts and vents without any oil residue. The aroma diffusers that come with an HVAC adaptor (brass fitting and plastic tube) can work with your HVAC system.
If you have elected for an HVAC type connection, the HVAC fan must be constantly turned on in order to dissipate the aroma particles. Not having the HVAC fan ON for a prolonged period of time can also damage your aroma diffuser.
No additional servicing is required for HVAC type connection. For optimum aroma diffuser performance please ensure proper HVAC connection, dust-free diffuser placement and timely fragrance oil refills also help.