Month: February 2020

Having good indoor air quality (IAQ) at your hotel’s indoor pool isn’t optional. It has a direct impact on equipment and building longevity, as well as the comfort, health and safety of your guests and employees.

Although pool room air will always have a degree of corrosivity, due to the presence of moisture that is usually laced with gases derived from the chlorinated water, the true fact of the matter is that great IAQ is absolutely possible if the right steps are taken.

When a hotel pool possesses good IAQ, guests will want to come back to that facility next time they are in town — even if they didn’t 100% put their finger on why they enjoyed that particular pool so uniquely.

What Causes Poor IAQ in Pools?

There are a number of possible causes for poor air quality in pools. Any one of them on their own will lead to issues.

One of the most basic is air distribution. The best quality air in a pool comes directly out of the dehumidifier. This air needs to be distributed down to where the guests are on the deck and in the water.  Without getting good air in the breathing zone, the IAQ will suffer and exacerbate an unhealthy and potentially hazardous environment.

Note that for the most part, people are breathing anywhere between the water surface — which is much lower than in a regular room — and 7 feet above the deck, approximately the height of a very tall human. Air must circulate at the deck level and across the water surface. In addition, the HVAC system must blend in the correct amount of outdoor air according to codes, plus the grilles/diffusers must have sufficient throw distance to direct air where it needs to go.

You should be able to feel the supply air a little on your head when you stand on the deck, but it’s also important to not create a strong draft as that will chill guests coming out of the water.

Avoiding condensation is critical to asset protection

The air distribution must also address areas of potential condensation, like exterior windows, sky lights and fire doors. They need to have the warm air blanket them fully to avoid condensation. This fact is often missed because designers forget that these surfaces are more likely to create condensation than in a regular room, due to the pool’s heightened dew point condition. Avoiding condensation is critical to asset protection, because the droplets that collect on windows and ledges can be corrosive and will lead to degradation where it occurs.

Another aspect of air distribution is providing ventilation to move harmful gases away from the surface of the water. These are a major cause of poor air quality in pools. The main type is trichloramine.

Trichloramine is a type of combined chlorine created through reactions between chlorine and contaminants in the water that contain ammonia. Many of these contaminants are introduced to the water by swimmers. Some examples are sweat, urine, body oils, makeup, deodorant and dirt. When the introduction of these contaminants outpaces the introduction of free chlorine, the chlorine reacts with them instead of fully oxidizing them. As a result, the chloramine levels in the water increase. Trichloramine rapidly off-gasses from the water and causes that signature “chlorine smell” of pools. A slight smell can water your eyes, while a strong one can drive guests away from your hotel and pool, while also accelerating damage to the building envelope due to their corrosivity.

The Two Keys to Ensuring Good IAQ

There are two key aspects of ensuring good IAQ:

1. The reduction, control, and elimination of chemicals off-gassing. Hotels can reduce contaminants entering the water and resulting trichloramine by encouraging guests to shower before swimming and to avoid urinating in the water. Technologies like UV water treatment and even special exhaust systems are available to minimize the issue as well.
2. Having an air distribution system that supplies sufficient air to the breathing zone, including across the water surface.

Achieving good pool room IAQ isn’t just relevant to new hotels being designed and built; it is also of critical importance to existing facilities. If your existing hotel pool is experiencing IAQ issues, there are likely some cost-effective strategies you can take to improve the air — and along with it, improve the experience you provide your guests while also protecting the hotel investment. There are many potential benefits to having a Dehumidified Air Solutions expert visit your site and review what options are available for improving your facility.

Want to take a deeper dive?

We’d love to discuss your unique pool environment and conditions to provide more detailed expert advice. Leave a comment below or complete the form on the right for a direct response.

Indoor pool spaces are meant to be comfortable places for hotel guests to enjoy recreational swimming. Temperatures are kept warmer than a traditional indoor space for swimmer comfort and energy savings. Additionally, relative humidity (RH) is generally kept between 50% and 60% so that the space humidity is very similar to what it would be like in any other room. When these two measurements (temperature and RH) are where they should be, an indoor pool area is a perfectly enjoyable environment and the hotel investment is protected for years to come.

Yet, pools often operate at different setpoints either because of problems with their dehumidification system or because they don’t fully understand the impact of their choices. Here are some reasons why your indoor pool conditions may not be right:

• Expectations have changed
• Worn down equipment
• Duct work not operational
• Exhaust fan not functioning
• Outdoor air intake blocked
• More outdoor air than required

Different Operating Parameters

A popular setpoint for hotel pools is 84°F water temperature, 82°F air temperature and no more than 60% RH.

Dehumidifiers are designed and selected for a specific air temperature and RH setpoint, also with a specific water temperature in mind. This is important because these three things will influence the water evaporation rate and that has an impact on whether the dehumidifier is going to be able to keep up with the load and maintain the space. Therefore, the dehumidifier works best when these parameters are not changed. A very popular one for hotel pools is 84°F water temperature, 82°F air temperature and no more than 60% RH (the RH typically ranges 50% when less active and up to 60% when busy.) These parameters are popular because hotel guests are kept comfortable whether they are in the water or fully clothed on the deck, just watching.

While 82°F can feel a bit warm when you are fully clothed, some facilities make the mistake of lowering the space temperature. Changing setpoints from the original unit selection criteria will have an impact on system performance and operating costs. if you set the room too cool, you will wind up with increased evaporation and a unit that may no longer properly maintain the space conditions. Conversely increasing the air temperature too much, while rare, would result in oversized unit that constantly hard cycles its compressor on and off for short periods of time, frequently over-cooling and over-dehumidifying the room. Either are not good operating scenarios and lead to guest discomfort, increased operating costs and greater wear and tear on the equipment.

Lowered Equipment Performance

Unless well-maintained, mechanical equipment will experience diminished performance over time. Indoor pool dehumidifiers are especially vulnerable to this because they operate in a typically corrosive environment and their ideal operating parameters are not always understood by people servicing them. While high-quality machines built today can often last 20 years, older models that are less corrosion-protected tend to last a lot less time.

Equipment performance has a direct impact on your bottom line.

Corroded or improperly operating components, such as cooling coils, heaters and condenser coils, lose their effectiveness over time. It is best to have these components be fully-protected with an anticorrosion coating to keep them operating at peak efficiency for the life of the equipment. Older components that have corroded can be replaced, however the hotel operator should consider the ROI of replacing old components versus getting new equipment that is equipped with modern features and better corrosion protection.

Additionally, there is much to be gained with regular maintenance of the equipment by people who understand how they should be operating. Internal cleaning, including washing of all coils (inside the unit and also the outdoor heat exchanger coils), can help stave off corrosion. Plus, coils can get dirty over the years and this also lowers their output. For this reason, it is recommended to regularly change return and outdoor air filters, about once per quarter, as they keep small airborne objects from getting caught in the delicate coil fins.

Other Changes

Besides setpoints, other things may have happened at your hotel pool to change the situation. Consider these as possibilities:

• Are all supply air and return air openings in your duct work operational? Sometimes they get blocked due to objects in the space, like plants or window treatments. Especially with floor-grade supply air openings, sometimes they are covered up because they were blowing air onto guests and causing discomfort. But, covering up grilles can limit effectiveness of the dehumidification system.
• The exhaust fan, which may be remote or inside your dehumidifier, could be non-functioning.
• Was the outdoor air intake blocked off to save money? For public spaces, having outdoor air is a code-requirement and closing it off completely can significantly deteriorate air quality.
• On the flip side, poor air quality in the space has led some facilities to have more than code-required outdoor air blended in. This can cause the dehumidifier to struggle because it must treat additional outdoor air. Keep in mind, more than necessary outdoor air is expensive to treat and does not guarantee better air quality. If your facility is following the code minimum for outdoor air but still struggles with air quality, it may be a good idea to have an expert review your facility because there are likely more cost-effective ways to address the problem than increasing the outdoor air intake.

Want to take a deeper dive?

We’d love to discuss your unique pool environment and conditions to provide more detailed expert advice. Leave a comment below or complete the form on the right for a direct response.