Ventilating Heated Indoor Pools & Spas
Inadequate wet area ventilation leads to
Indoor pool areas are not just a bigger bathroom. Careful consideration needs to be exercised when planning and building such areas especially as water is to being heated constantly over a period of months
Air ingress dictates where egress is to be located on the roof. Wet area ventilation employs heat and pressure dynamics to facilitate air movement. In all cases ingress to egress is to be balanced and appropriate to the disposition of the area being ventilated.
It is not a matter of ingress being in a convenient location and a vent(s) anywhere on the roof for the purpose of aesthetic conformity.
Problems arise when practitioners focus only on the aesthetics and not on the performance necessary.
The client may not know what is in store for them in the short term but they soon acquire an education which leads to uncomfortable questions being asked in the not too distant future.
The one thing that practitioners fail to realized is that this particular wet area has chlorine salts present and cannot be simply considered as an oversized bathroom.
Volume replacement is critical in both quantity and quality. Recirculating the air through a dehumidifier may remove the moisture but not the odour nor will it improve the air quality, so an expensive quick fix is not the answer.
With pressure being greatest at ground level, air ingress is required to be within 600mm of the ground. This dynamic is used to facilitate efficient ingress into the building and can only be done if efficient and proportional displacement is present.
You do not want the roof ventilator to create negative pressure and thus establish an unwanted direct line from ingress to egress.
You do not need a roof mounted fan but you do need good low level air ingress.
Indoor Pool / Span Ventilation (mechanical ingress)
Where low level peripheral natural air ingress is not available. This approach is for air ingress only, do not use mechanical for egress.
Should mechanical means be used to introduce air volume into an area it should be done without establishing flow paths.
The introduction of air to the area must be in a manner as to pressurize the area with the roof ventilator(s) providing relief.( similar to inflating the tyre of your car).
You do not want a direct line established from in to out ingress must be slow and positive, egress must be laminar. A pulsing mode is more effective than a continuous flow.