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Spa Floating Tank Room Air Change Per Hour?

Updated: Feb 13

The recommended air change rate per hour for a spa floating tank room can vary depending on the specific requirements and regulations in your region. However, a general guideline is to have at least 4-6 air changes per hour to maintain good air quality and prevent the buildup of humidity and odours.

The size of the room and the number of people using the floating tank should also be taken into consideration when determining the appropriate air change rate. It is important to consult with a professional HVAC engineer or technician to ensure that the ventilation system is properly designed and installed to meet the specific needs of the spa floating tank room.

ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) provides guidelines for ventilation rates in different types of spaces, including spa and pool areas. According to ASHRAE Standard 62.1-2019, the minimum ventilation rate for a spa area is 68 cubic metres per hour (m3/h) per occupant.

To convert this minimum ventilation rate to air changes per hour (ACH), you would need to know the volume of the spa area and divide it by the ventilation rate. For example, if the spa area has a volume of 1,000 cubic meters and you want to achieve 6 air changes per hour, you would need a ventilation rate of 6 x 1,000 = 6000 m3/h. or 1667 lit/s.

It is important to note that the minimum ventilation rate recommended by ASHRAE may not be sufficient to provide optimal indoor air quality in all situations, especially in spaces with high humidity levels or other contaminants. It is recommended to consult with a professional HVAC engineer to determine the specific ventilation requirements for your spa area based on factors such as occupancy, size, and use.

Engineers normally select ACH =20 to 30 for the spa. What is the optimum amount of ACH?

the running cost of ventilation from ACH=6 to ACH=20 is huge money!!!

We used Computational Fluid Dynamics (CFD) to optimise the air change rate per hour for moisture removal in a spa floating tank room. CFD simulations can provide detailed information about the airflow patterns, temperature distribution, and moisture levels in the room, which can be used to design and optimize the ventilation system. By simulating different air change rates and airflow patterns, CFD can help identify the most effective ventilation strategies for moisture removal while minimizing energy consumption and maintaining good indoor air quality. This can include optimising the placement and size of air supply and exhaust vents, adjusting the temperature and humidity setpoints, and incorporating other moisture control strategies such as dehumidification systems or air purifiers. Overall, using CFD simulations to optimize the air change rate for moisture removal can help ensure that the spa floating tank room provides a comfortable and healthy environment for users while minimizing energy costs and reducing the risk of moisture-related problems such as mould growth or corrosion.

We simulated a floating tank room for three conditions:

a) almost no ventilation (ACH=0)

b) Medium ventilation (ACH=8)

c) High ventilation (ACH= 20)

The following animations show the relative humidity of the room:

Blue colour: Relative humidity = 100%

Red Colour: Relative humidity = 0%




Here are the outcomes:

We can see that CFD found ACH=8 is sufficient for this floating room. This outcome can help to optimise the energy cost for ventilation.

contact Deratec to discuss more!


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