The Perfect Solution for Reducing Humidity when using a PTAC Unit Product Embeds
What is a PTAC unit and how does it work? PTAC units are mainstays of hotels, motels, and dormitories across the country. Their use dates to the mid-1980s, when hotel chains began installing air conditioning units in guest rooms. These units were less expensive to install and operate than central air and took up less space. But PTAC units have one major flaw: they are not designed to dehumidify and in some cases, they have added more moisture into an already humid space. As a result, many hotels began to suffer dampness, moisture issues, and mold problems; and these are still being seen today after nearly three decades.
What is a PTAC Unit & Why Do You Need to Dehumidify?
PTAC units are typically found in hotels, college dorms, military bases, and housing authorities. PTAC, or “Portable Terminal Air conditioner,” is a type of self-contained heating and air conditioning unit that heats and cools small living spaces.. They are most commonly seen under the windows of hotels and motels across the country. PTAC units can be installed in an exterior-facing wall to cool the air. Because PTAC units do not require ductwork, they are sometimes called “through-the-wall” air conditioners. They save money, increase energy efficiency, and are easy to install.
Why do Dormitories, Apartment Buildings, and Hotels use PTAC Units?
In buildings, such as hotels, college dorms, and military housing, a central heating and cooling system can be very expensive to operate with limited available space to install duct work. A PTAC unit, however, is designed for on-demand use in individual rooms. Additionally, each room can be set to a unique temperature based on the preferences of its occupants. Many people use PTAC units for apartments in lofts and attic spaces, sunrooms, basements, or when adding an additional room to their existing home. Others even install these units in tiny homes to avoid adding extra ductwork to the main HVAC system.
Common Problems & Myths with PTAC Units
Myth #1: PTAC units can dehumidify a room if installed and operated correctly
PTAC units cannot dehumidify. To provide good dehumidification, PTAC units should remove the latent moisture load during all operating conditions. To do this, PTAC units should be sized to handle full- and partial-load conditions. However, because of conservative load analyses and the industry belief that temperature control is more important than anything else for guest comfort, many PTAC units are oversized. An oversized unit does not cool the space as quickly and efficiently as a properly sized unit.
Myth #2: PTAC units can pressurize rooms
PTAC units do not provide adequate ventilation. They cannot pressurize a building space. To achieve pressurization, ventilation air must flow through the vent door in a volume greater than can be removed by the bathroom exhaust fan and room air leakage, a condition which is impossible. Moreover, when the room is occupied or the toilet exhaust is operating, the PTAC fan must run at all times to provide ventilation and pressurization. However, since guests can control the PTAC fan operation, it will be unable to offer positive pressure because both requirements will not be met at all times.
Myth #3: PTAC units have adequate outside air ventilation
Another common problem is that the design of PTAC units does not meet code requirements for ventilation, even though most hotel design and construction professionals believe that it does.
If a PTAC system relies on the equipment to meet code, then a guest can’t be allowed to change fan speeds or turn the unit off. The outdoor airflow can’t be accurately measured to verify compliance with codes.
One reason PTAC units cannot provide code-required ventilation, pressurization, and dehumidification is because guests control the hotel PTAC unit fans. Without limiting this effect, occupancy of PTAC rooms could be pretty challenging to manage. Furthermore, the pressure drop through the vent door air filter is higher than through the evaporator coil and filter. While many manufacturers describe how a vent door may be open or closed, they usually provide little guidance about moisture problems resulting from an open vent door. In short, contractors and hotel owners are uninformed concerning the increased risks of moisture problems due to open vents.
Mold Growth Hazards when using PTAC Units without Dehumidifiers
According to Ahmad A. Pesaran, “air humidity must be controlled below 60% relative humidity (RH) to avoid the growth of mold and mildew.”1
PTAC units can cause problems in humid environments. Humidity above 60% can cause mold growth, mildew formation, and other potential health hazards. This is because of the increased number of airborne particles present when the air is moist. Humid conditions can occur during high heat or low cool cycles and overnight when systems run continuously until sunrise.
In spite of the common belief, the reality is that home and hotel PTAC units DO NOT dehumidify. There is no way for them to remove moisture from the air since they’re not equipped with separate coils for heating and cooling.
PTAC units are designed to cool, not to dehumidify. They can’t remove moisture from the air at all – they just move it around, so you shouldn’t expect more from a PTAC unit than it can deliver.
Fixing PTAC Humidity Issues: Hotels, Apartments, Multi-Family Units
Mold and humidity aren’t just unsightly; they can make guests and/or tenants uncomfortable and in some cases can make them ill. An unpleasant experience like that may discourage your guests from coming back to your hotel or worse begin litigation where tenants are concerned.. Installing a dehumidifier helps PTAC units to resolve humidity concerns and related issues including mold.
A dehumidifier will help balance the relative humidity in your hotel rooms, dorms, and apartments to suit the most discriminating tenant or patron. It will remove moisture without interfering in any way with the operation of your PTAC. An in-wall dehumidifier or on-wall dehumidifier is a good investment because it takes up little space, requires little effort for installation, operates independently of the PTAC, and can be adjusted on-demand by any guest or tenant.
The Perfect Solution for Reducing humidity when using a PTAC Unit
Using a PTAC unit to heat and cool your space may be a reasonable option if you live in a humid climate; however, it would be a mistake to count on this single-purpose unit to do more than dehumidify the room. This error will lead eventually to excess moisture and dampness that can degrade the structural integrity of the building itself.
Rather than upgrading your entire HVAC system, all you need is to complement your PTAC unit with a practical, dependable, and efficient on-wall or in-wall dehumidifier. An IW25 dehumidifier is a wall mounted, tankless dehumidifier. Adding supplemental dehumidification with PTAC units is a great solution to help combat high humidity issues.
The IW25-4 Dehumidifier utilizes its integral humidistat to monitor the environmental conditions. When the relative humidity goes above the selected set point, the dehumidifier will energize. Air is drawn across an evaporator coil, which is cooler than the dew point of air. This means moisture will condense out of the air. The air is then reheated through the condenser coil and distributed back into the room. The IN Wall dehumidifier is designed for recessed wall mounting. For semi-recessed applications an IDS Exterior Sleeve (sold separately) shall be used. The ON Wall dehumidifier is designed for direct surface wall mounting on surfaces including drywall, cmu block, masonry, concrete, stucco, etc.
Incorporating an escape route to control moisture is important. With a stand-alone dehumidifier, you can keep your indoor relative humidity levels less than 60 percent for the entire year. It’s important that the dehumidification system runs independently from your HVAC system to ensure proper indoor humidity at all times.
PTAC units are cost-effective and energy-efficient solutions to keep you comfortable; however, you shouldn’t rely on these single-purpose units to pressurize or ventilate the room. This misguided confidence in your PTAC unit will eventually result in humidity, mold, and moisture problems that will affect your guests, your tenants, or you and your family. Using an on-wall or in-wall dehumidifier alongside your PTAC units can ensure everyone’s personal comfort and satisfaction. The best part is the hands-free wall mounted dehumidifier not only removes excess moisture but has a lock out system which prevents tenants, hotel guests, and others from changing the set point. It allows full control of supplemental dehumidification.
Do PTAC Units REALLY need an Innovative Dehumidifier for the Best Living Conditions?
Yes, supplemental dehumidification independent of PTAC units is a cost effective necessity and removes moisture trapped inside apartments and hotel rooms.
As the demand for efficient housing increases, sufficient ventilation is limited due to tighter envelopes. Since moisture is continuously added to the air indoors, supplemental dehumidification is essential to condense and remove moisture trapped in your property.
The purpose of supplemental dehumidification is to remove moisture from the air and help lower relative humidity (RH) below 60%. From luxury condo builds to large apartment or hotel buildings, homes need to have a dehumidification solution that prevents mold and ensures comfortable living conditions for occupants. Supplemental dehumidification will adjust RH levels indoors to compliment the capabilities of large scale cooling systems without necessitating exhaust fans running all day every day.
Considering a mini-split? Read this first.
Innovative Dehumidifier Systems is available to guide you through the entire process and the installation of these long-lasting dehumidifiers is simple and straightforward.
Bonus: Using a Dehumidifier with a Mini-Split Set Up
After conventional HVAC units made their debut in Japan in the 1950s, it soon became clear that these noisy, bulky systems needed to be re-engineered to meet the stricter requirements of small homes and MFUs situated in densely packed urban environments. Mini-split systems were created as a quieter, space-saving heating and cooling option that would allow the temperature of individual rooms or interior zones to be efficiently managed.
Today there are a variety of these popular mini-split systems on the market. Just as in the case of any other substantial investment in home or MFU improvement, it is important for buyers to understand the characteristics and capabilities of these units before committing to a purchase.
The popularity of mini-split systems continues to grow. The latest versions are even more energy-efficient and run even more quietly than previous models. Some units, fitted with a special “dry” mode, advertise their ability to dehumidify a room without cooling it. In theory, mini-split systems seem to be a practical solution to simplify and economize home and MFU installation for cooling, heating, and dehumidifying systems, but do they have a documented performance record that suggests superior capabilities in all categories?
