Swimming Pool (Natatorium) Enclosure Exhaust Only?

[Wareagl487]

I recently produced a design for a 3,700 sq. ft. enclosed pool. The pool will be used for teaching swimming and possibly club events. Knowing the owner is very conscious of cost, I squeezed the design parameters for pool water (80 degrees) and space temperatures (80 degrees) to minimize the total tonnage required - got it down to 17 tons.

The owner is still balking over cost of the equipment and wants me to change to exhaust/heat only. I find nothing code wise that prevents this. ASHRAE Handbook chapter 4 address need for humidity control and cautions high humidity levels are destructive to building components. ASHRAE also mentions "codes" require a minimum of 6 AC/hr adding that the rate "may be inadequate for some occupancy and use."

Anyone have experience in venting only? Any values for AC rates? I was thinking more in line with 15 to 20 AC/hr - project in Houston, Texas.

Thanks for any input you can give.

Andy W.

 

[sprinkler1000]

I would specify a dehumidifier. Check airflow to be about 6 ac/hr . You will need only a small amount of outdoor air.

Working with a 100% outdoor air and heating it is an energy waste, and I dont know if you can control humidity as it should be.

 

[lma1]

“Exhaust/heat only” system is never recommended. I also “would specify a dehumidifier.”

Our Pool Regulation (BC Reg. 296/2010) is not specific on the AC rates. Like ASHRAE, the recommended min. operating guidelines as published by the BC Recreation & Parks Association is 4 – 6 ACH. The actual air requirements of course depends on the evaporation rate of the pool water, the min. air required to remove this evaporated water (a useful equation appears in the 1982 ASHRAE Applications Handbook) and the heating load. The outdoor air must also satisfy ASHRAE Std 62 (the 2001 ed. as referenced by our VBBL (Vancouver Bldg Bylaw) based on pool area or the # of occupants.

 

[ChrisConley]

I typically see this arrangement in hotel pools. The primary issue is that when it is humid outside, you have no ability to dehumidify. Many of these pools show signs od moisture damage. I would push hard for a dehum system. Dectron has some tech material online that may help.

 

[itsmoked]

Isn't a dehum a waste here? As you drop the humidity you will just suck more out of the pool faster.

I'd rather see the building be moisture proofed. Something like concrete with gable windows that can use gravity to ventilate the space.

My wife works in an indoor pool that's kept at 93F. One side of the building are those glass bricks the other is multiple offices lined along the pool. This structure has been in service continually for about 40 years with no obvious moisture issues. It does have some high and low windows they keep open.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[cry22]

Smoked
You wife works at a special place, it is a different application.

93F is a therapeutic pool (many football teams have such a pool for players after all the hits) that dos not need dehumidification. Such pools use what is called a "push-pull" system.
Why would you dehumidify (meaning cool) a space that needs a room temperature a 93F?

 

[Wareagl487]

As always guys, ya'll have been of a great help!!!

A letter was sent to the "tenant" warning him of all the hazards of not providing a proper pool HVAC unit with dehumidification. This facility is being converted in an existing strip mall - they will be leasing the space. The architect has been made aware - so I feel it his responsibility to look out for the owners interest.

Cry I believe Smoke is referencing pool water temps, not space. Either way, IMHO enclosed pool require a dedicated pool dehumidification unit.

Andy W.