Engineering Considerations for Indoor Pools.

In any indoor pool project it appears that the HVAC engineer is the one most between the rock and hard place. The architect at least has the freedom to design, but the engineer has to work his magic and make, what was designed by others, work. And that is not so easy. The engineer has to heat and cool the place but also control the humidity. He has to introduce outside air to meet the code requirements, heat and cool the outside air, make sure there are enough air-changes, make sure the air quality is acceptable and at the same time control the humidity. Too much humidity is bad, will help deteriorate the building in short notice, where as too little humidity will increase the cost of operating the pool and often dissatisfy the users of the pool.

The engineer is also responsible for equipment selection and the offerings are many. In the dry territory, let’s say left of the Mississippi, outside air will help to dehumidify in the summer but might be responsible for over dehumidification in the winter. On the East Coast it works quiet different with warm humid outside air adding to the humidity in the summer and only little support to reduce humidity from the winter outside air.

Some systems advertise the maximum use of outside air, other will tell him that energy can be saved by using the minimum amount of outside air. The engineer will have to look at all parameters to come to a final selection. Note that no indoor pool is equal to the next one, and just designing what was used in the last pool can create terrible headaches.

The engineer will find that all indoor pool dehumidifiers are sized for summer operation (high wetbulb) but at the same time he will realize that during mid winter the indoor pool is in really in danger. That is when cold outside air will help in creating condensation which is the main culprit in bringing the building down.

And that is the most important fact the engineer has to realize. Indoor pool dehumidification first and foremost must protect the building. It is not just peeling paint and some water tracks on the wall that will annoy the owner. It is a collapsing roof, with swimmers in the pool, that cause the nightmare.