March 2020 – Dehumidified Air Solutions

Does Your Dehumidifier Need Frequent and Expensive Repairs?

October 21, 2021March 24, 2020

Indoor pool dehumidifiers are precision pieces of equipment. From the materials they are constructed with, to their actual layout and inner workings, they vary in numerous ways from other types of HVAC equipment like air handlers and air conditioners. The environment they operate in is also significantly different than other HVAC systems.

These two facts mean that there are not many service technicians with deep knowledge when it comes to diagnosing and repairing indoor pool dehumidifiers. Often, basic problems can be overlooked and many service visits only see resolution after the manufacturer’s customer support department gets involved.

To help you avoid expensive and unnecessary service company visits, here are some things to consider when you experience challenges with your indoor pool dehumidifier.

Finding the Reason

Anytime you experience an operational challenge related to the room environment, you should think of the dehumidifier. The first question to ask is whether the dehumidifier is operable.

How old is the unit?
Is it blowing air as intended?
Are any of the fans impeded? They may need a belt replacement, if applicable, or could be blocked by foreign objects.
Have any parts failed?
Is there major corrosion on key parts such as the coils?
Are the filters still good or do they need replacement? It’s recommended to change them about once per quarter.
Has fluid or refrigerant leaked?
Is the outdoor condenser experiencing any similar issues? For example, it may be blocked by some debris that should be cleared away.

The older the unit, the more likely there is a mechanical issue to blame. It’s always recommended to periodically inspect and maintain the dehumidifier to keep track of any issues that may arise and prevent as many as possible. Preventative maintenance is always the best kind of maintenance.

If there is a mechanical or electrical problem with the dehumidifier, it should be addressed by a qualified service technician.

Check the Conditions

Before you call in a service company or contact warranty support, double-check the dehumidifier’s operating conditions. What space conditions (air temperature and RH, plus water temperature) is it currently set to maintain? Compare these to what the unit was designed to maintain (usually on the nameplate). If they are different, then the dehumidifier should be reset to follow what it was originally designed for.

We have observed many facilities turn down their space conditions over the years, often at the request of patrons. While it’s true that patron comfort should always be the priority, unfortunately once a pool has been designed for a certain set of conditions, there are negative things that happen when setpoints get changed. For example, if you lower the air temperature by just a couple of degrees the water will increase its evaporation rate. The result will be higher operating costs to heat the water as well as, ironically, patron discomfort. (As patrons exiting the pool will feel chilled as the water on their skin evaporates quicker.)

Are the Filters Dirty?

Dehumidifier coils are much deeper than standard air conditioner coils, which helps them effectively condense moisture out of the air. It also makes them hard to clean thoroughly if any foreign particles get into them. Therefore, it’s extremely important the air filters are changed consistently to prevent that from happening.

It’s also important to note that dirty filters can impede airflow over the coil, which can cause inefficiency and potentially lead to trips on low pressure. This could potentially damage your unit!

The good news is that filters are inexpensive and well worth the price of regular replacement, compared to what it will cost the operator through inefficiencies caused by dirty coils. Refer to the stickers on the equipment or submittal documents for the type of filter equipped (or inspect the filters themselves). Any number of local stores may sell suitable replacements. Check filters for replacement at least once per quarter

Ductwork

If it doesn’t seem like there is a problem with the dehumidifier itself, you may be experiencing an air distribution issue.

When to Replace?

One good time to replace is near the end of the normal life cycle when several other issues you want to fix have been identified. Bundling the work can be more efficient and easier to get funding for since you can show numerous problems will be resolved.

The normal lifespan of a high-quality dehumidifier is 10–15 years. In perfect conditions, they can last much longer. We’ve seen some still in great shape beyond the 20-year horizon. When to replace is entirely reliant on what condition the unit is in.

Cheaper dehumidifiers tend to have a shorter lifespan because they are built with lower-end components and use fewer corrosion protections. A five-year replacement cycle is common.

In many ways, a dehumidifier is like a car in terms of knowing when to replace. If the unit is constantly raising alarms and shutting down, frequently needing repairs and losing major components like coils or compressors, then it’s probably time to replace. Like a car, the repair bills add up and eventually it would be cheaper to buy a whole new machine rather than replace yet another compressor.

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.

Does Your Hotel Pool Suffer from Sweaty Windows, Doors and Ledges?

May 1, 2020March 23, 2020

Whether big or small, all hotels pools must have robust measures to control humidity and prevent condensation.

Obviously, an indoor pool has the potential to produce an enormous amount of moist air. But that’s not the only reason condensation is a unique concern in pools. Their air temperature is also much higher than a regular room, meaning their dew point is also quite a bit higher than usual. Combined, these factors mean condensation can easily occur in a pool while it wouldn’t normally be an issue in another room.

Dew Point

The dew point is the temperature at which moisture in the air condenses when it comes into contact with a surface that’s colder by 1°F or more.

You only have to enjoy a cold drink on a summer day to experience dew point and condensation firsthand. When you pour a cold beverage into a glass, condensation will begin to form on the outside of the glass almost immediately. This is because the surface temperature on your glass is below the ambient dew point temperature.

This happens at indoor pools across North America every year when outdoor temperatures fall during the winter. Exterior-facing surfaces that have low insulation values, like windows, skylights and fire doors, are very likely to have a surface temperature that is below the room dew point during cold weather. As a result, moisture condenses on them.

The Dangers of Condensation

There are two major concerns for hotels around condensation at their pools:

It can damage the hotel assets.
In doing so, the guest experience will be negatively affected; sweaty windows are unsightly, and visible mold or corrosion could drive guests away.

Condensation triggers a destruction process, since it allows mold and mildew to grow on the materials from which a building is constructed. It also frequently foments corrosion on metal surfaces.

In a hotel pool, air will almost always have some degree of corrosiveness due to chemicals that off-gas from the water.

Other than condensation that you can see on surfaces, there is a hidden danger. If allowed to permeate the building walls or roof, condensation will not only instigate mold-induced deterioration, it will also cause additional devastation of the structure in winter. This is because when temperatures drop below freezing point, the moisture that’s soaked into the structural components of the building turns into ice and expands, putting additional stress on the materials and causing fissures and cracks that compromise the integrity and safety of the structure. That is why it’s critical all hotel pool rooms have a properly constructed envelope with a vapor barrier.

Preventing Condensation

The pool room dehumidification system is an essential part of condensation control and preventing. It must maintain the interior conditions (temperature and RH) at the correct, desired setpoints as determined when the hotel pool was constructed. The air ducts must distribute air all around the pool room, taking special care to direct warm airflow against surfaces that are likely to drop below the dew point of the room.

It’s important to ensure the entire surface is covered by warm airflow. Mother nature will tell you on the first cold day how good a job you’ve done — it’s common to find the top of a window condensation-free because it’s near a diffuser, but the bottom is sweaty because the diffuser does not have enough “throw” distance to work the air all the way down.

If your hotel pool room struggles with this aspect to HVAC, then it is a smart idea to have an expert come in and review your dehumidification system. They will have the experience and the knowledge to identify areas that can be improved to better control condensation. In many cases adjustments can be made for little cost. For example, one facility was recommended to rotate their ductwork to improve supply air diffusion.

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.

Can You Smell Your Pool from Other Parts of the Building?

May 1, 2020March 17, 2020

While it’s true indoor pools can be perfectly safe and healthy environments with good air quality, they must also be contained environments. After all, even great-quality air from a pool room is not air you’d want to have mixing into the lobby!

If your guests are being greeted at your hotel by a scent of the pool, rather than a smile from the concierge, then that is a problem with the potential to damage guest perception as well as the hotel property.

Why Can I Smell the Pool Without Being Near the Pool?

Normally, indoor pool rooms should be contained from other areas of the building they are within. This is accomplished through a number of means, including:

A physical airlock or vestibule to enter the pool room.
A separate HVAC (dehumidification) system with its own ductwork.
The pool room is kept at a negative air pressure.
A vapor barrier ensuring the higher moisture levels in the pool area stay in the pool area

These measures ensure that the environment is a closed system for the comfort of all building occupants, including guests and employees.

Sometimes, however, air can drift out of the room. A common cause is related to the dehumidification system. Indoor pool dehumidification systems commonly include exhaust fans that ensure the environment is at negative pressure. Generally, the exhaust fan is separate from the dehumidifier. In hotels they are located in the pool room and ideally draw in air from above the spa if you have one.

If the exhaust fans are off, or not at the right speed, then they may not be exhausting enough air to the outside to keep the space negative. As a result, the code-required outdoor air that the dehumidifier introduces to the space will be greater and result in a positive-pressure situation that pushes air out to the rest of the hotel.

Additionally, a positive-pressure pool room would worsen the phenomena known as vapor migration. This is particularly acute during cold weather, where high pressure moisture inside the pool room tries to migrate through the building envelope to equalize with the lower pressure moisture levels outdoors. While this is a predictable and normal occurrence, it is vital that it is mitigated by special design of the vapor barrier in the building envelope during construction. Anything but a negative air pressure indoor pool exacerbates moisture trying to migrate by forcing air through the envelope.

If you find that you can smell your pool room without being in it, the doors/vestibule to the room should be checked to ensure it is properly sealed. Then, examine the exhaust system to ensure it is removing enough air from the space for negative pressure. It should be exhausting 10–20% more air in CFM than is being brought in from the outdoors. Because indoor pool environments can be complex, it may be valuable to bring in an experienced expert as they will be familiar with this particular problem and how to resolve it.

Of course, another thing to keep in mind is that your indoor pool should not have a strong acidic or chlorine smell. This is an indicator of a potentially hazardous environment and should be addressed as quickly as possible.

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.