BSI-012: Balancing Act – Exhaust-Only Ventilation Does Not Work
There. I said it. It just does not work. OK, it works sometimes1. But it does not work in tight building enclosures and certainly not in new houses, apartments, townhouses and row houses. Basically in nothing new that we are building. Because it sucks – literally. I know we were here before (“Unintended Consequences Suck”, ASHRAE Journal, June 2013) but we have to come back and deal with it again. Why? As amazing as it seems, things have gotten worse and are going to get worse. But the good news is as they become intolerably bad we will end up finally dealing with them. Not quite there yet, but almost.
This next part should be obvious – but is apparently not to some people and quite acceptable to others. Exhaust-only ventilation leads to depressurization in houses, townhouses and row houses that are constructed to meet the 2015 International Residential Code and significant depressurization in apartment construction constructed to meet the 2015 International Building Code. In single family detached houses this leads to contaminants being pulled from attached garages – especially houses with bedrooms over garages. Contaminants are also pulled from under slabs – if radon was valuable we would mine it this way – and what better way to bring soil gas, herbicides and pesticides into a home?
In row houses and town houses exhaust-only ventilation leads to air being pulled from neighboring units as well as from attached garages and from under slabs. In apartments exhaust-only ventilation leads to air being pulled from neighboring units and corridors.
In apartment construction the corridor issue is a smoke and fire issue. You would think this might be something we ought to care about? Well we do. In a serious way. But from a “tightness” perspective not from a pressure perspective. We are getting good at the compartmentalization part – especially because we now test for it. But the compartmentalization makes the pressure issue way worse when we use exhaust only-ventilation.
Why not supply ventilation? Supply-only ventilation works in detached single family houses but not in apartments and townhouses and row houses as it drives air into neighboring units and we have the associated odor and contaminant transfer issue. You can’t ever make them “tight-enough” to prevent this – there are practical limits to compartmentalization.
Kinda leaves us with only one option that works in everything everywhere – balanced ventilation. Notice the words “everything” and “everywhere”…. But the Model Codes don’t encourage it and ASHRAE Standard 62.2 and RESNET actively discriminate against it2. That is insane. We are penalizing better systems when we incentivize poor systems and don’t encourage good systems. This is what I mean by things getting worse. We are incentivizing worse. We are discriminating against good. Note the word “insane”.
Are we done yet? Nope. How do you deal with exhaust vented kitchen range hoods? How about vented clothes dryers? The only viable options are interlocked powered make-up air3 for both or not using a vented clothes drier and going to condensing dryers. Or venting the apartment unit or house through the kitchen range hood and providing ducted supply air directly to the apartment unit or house. Good idea in compartmentalized buildings and low rise but not in tall buildings using central systems.
Not in tall apartment buildings? Huh? Yes, we have done this for years in tall apartment buildings. But there are two fundamental problems with large roof top exhaust systems pulling from every unit interlocked with large roof top supply systems ducted to every unit.
First, the approach tends to over-ventilate the entire building because the systems run all the time and units get ventilated regardless of whether they are occupied or not. Second, fighting the stack effect is not a trivial matter. Most units with central roof top exhaust and supply end up being over-ventilated or under-ventilated – by large margins. And all this is exacerbated by failure to compartmentalize units, corridors, elevators, utility shafts and stairwells. Yes, yes we were there before (“How Buildings Stack Up”, ASHRAE Journal, February 2014).
We need to compartmentalize (Figure 1 and Figure 2) and we need have individual distributed balanced ventilation systems in apartment buildings and row houses and town houses (Figure 3). And as I mentioned we are getting the compartmentalization figured out. And we are certainly getting new houses, town houses and row houses tight. Why? Again, I mention for emphasis, we are testing them. These things are code requirements and we are testing for them and meeting them.
Figure 1: Compartmentalization – This is what it means. No air from the top of the “cube” or the bottom of the “cube” or the sides of the “cube”. And we go out of our way to make the front of the cube “tight” as well. When you “suck” where does the air come from?
So, distributed balanced ventilation systems work in everything everywhere. But, and a big but, in small units and small houses we are going to need supplemental dehumidification. Aw man…yes, pretty much everywhere south of the Mason-Dixon Line and east of Interstate 35 in Texas. In hot-humid climates and mixed-humid climates part load humidity cannot be controlled without supplemental dehumidification. Relax. Everyone relax. This can be accomplished with stand-alone dehumidifiers. We have the technology. And yes, we were here before. What has changed is that we now have better and more options available. We have the technology (Figure 4). Small wall-mounted fit-in-the-stud space dehumidifiers. A nice improvement over the older technology (Figure 5 and Photograph 1).
Figure 4: Supplemental Dehumidification – Relax. Everyone relax. This can be accomplished with stand-alone dehumidifiers. Small wall mounted fit-in-the-stud space dehumidifiers. A nice improvement over the older technology.
Don’t forget the vented clothes dryers. They extract 200 cfm or more from units, houses, row houses and town houses. Best solution, don’t use them. Use condensing clothes dryers. The big change for condensing clothes dryers in the last few years is that manufacturers have figured out there actually is a market for them. Yes, we have had condensing clothes dryers for quite a long time – but not large ones that actually dry clothes before you finish reading “War and Peace”4. We got large “SUV” sized ones “turbo-charged” as befits us non-Europeans.
What about kitchen range hoods? Yes, I know we were here before (“Deal with Manure & Then Don’t Suck”, ASHRAE Journal, July 2013). But things are getting easier. We are getting better capture efficiency with better hood design and that means we can get away with lower exhaust flows (Photograph 2 and Photograph 3). And we are on the verge of getting make-up air systems that are premanufactured and designed for residential applications. Right now you have to be a real engineer and design your own. You have to duct the make-up air under the cook top and decide how to precondition the or not.5
Can you get away with really small kitchen range hood exhaust that has high capture efficiency in a tight enclosure? Yes, maybe, I think, not sure. Less than 100 cfm of exhaust intermittently? Have not done the work. No one really has. Someone should. Note that intermittently means not all the time.
So what should these balanced ventilation systems look like? I’ve been playing with a couple that follow.
Each system is balanced and has provision for powered interlocked make-up air for vented kitchen range hoods. Each system is designed to operate in single family detached houses, town houses, row houses or compartmentalized multifamily units and with distributed heating and cooling systems or central systems where only hot water or chilled water or refrigerant is distributed, not air.
The first system (Figure 6) uses an outside air duct is connected to the return side of the air handler and the air handler operates continuously. The air handler is interlocked with a continuous bathroom exhaust fan. The rate at which outside air is brought in through the outside air duct is matched by the exhaust rate of the bathroom exhaust. For example, if 45 cfm is supplied via the outside air duct then the bathroom fan exhausts continuously at a rate of 45 cfm. In apartment units with only one bathroom this is pretty easy. Single exhaust fan is used. If two or three bathrooms are in the unit or we are dealing with a single detached house or town house or row house then the exhaust rate is split between the bathrooms. A single exhaust fan is used with an exhaust grille in each bathroom. There are controls available to make all this work. The individual fans operate at a low speed for general ventilation and intermittently at a higher rate when the bathroom is in use. A vented kitchen range hood is ducted separately to the exterior and is interlocked with a separate make-up air fan.
Figure 6: First System – Outside air duct is connected to the return side of the air handler and the air handler operates continuously. The air handler is interlocked with a continuous bathroom exhaust fan. A vented kitchen range hood is ducted separately to the exterior and is interlocked with a separate make-up air fan.
The second system adds supplemental dehumidification provided by a dehumidifier (Figure 7).
The third system (Figure 8) uses a fully-ducted heat recovery ventilator (HRV) or a fully-ducted energy recovery ventilator (ERV) providing balanced ventilation independent of the forced air conditioning system. The HRV/ERV extracts air from the bathroom(s) and supplies air to the bedroom(s). The rates modulate based on switches in each bathroom uping the rate intermittently when the bathrooms are in use. A vented kitchen range hood is ducted separately to the exterior and is interlocked with a separate make-up air fan. It is a bad idea to vent the kitchen range hood through an HRV or ERV. Did I mention that this is a bad idea?
Figure 8: Third System – Fully-ducted heat recovery ventilator (HRV) or a fully-ducted energy recovery ventilator (ERV) providing balanced ventilation independent of the forced air conditioning system. The HRV/ERV extracts air from the bathroom(s) and supplies air to the bedroom(s). The rates modulate based on switches in each bathroom uping the rate intermittently when the bathrooms are in use. A vented kitchen range hood is ducted separately to the exterior and is interlocked with a separate make-up air fan. It is a bad idea to vent the kitchen range hood through an HRV or ERV. Did I mention that this is a bad idea?
The fourth system also adds supplemental dehumidification with a dehumidifier (Figure 9).
The fifth system (Figure 10) works in apartment units or exceptionally efficient houses. A fully-ducted heat recovery ventilator (HRV) or a fully-ducted energy recovery ventilator (ERV) provides balanced ventilation independent of the space conditioning system. That space conditioning could be a packaged terminal heat pump (PTHP) as shown, or in the case of exceptionally efficient houses, mini-split or multi-split heads. The HRV/ERV extracts air from the bathroom(s) and supplies air to the bedroom(s). As in the previous cases a vented kitchen range hood is ducted separately to the exterior and is interlocked with a separate make-up air fan. Note, that with exceptionally efficient houses, even when using more than one head some mixing is necessary to provide thermal comfort.
Figure 10: Fifth System – System for apartment units or exceptionally efficient houses. A fully-ducted heat recovery ventilator (HRV) or a fully-ducted energy recovery ventilator (ERV) provides balanced ventilation independent of the packaged terminal heat pump (PTHP) conditioning system or in the case of exceptionally efficient houses independent of the heads of multi split systems. The HRV/ERV extracts air from the bathroom(s) and supplies air to the bedroom(s). As in the previous cases a vented kitchen range hood is ducted separately to the exterior and is interlocked with a separate make-up air fan. Note, that with exceptionally efficient houses, even when using more than one head some mixing is necessary to provide thermal comfort.
The sixth system adds supplemental dehumidification in the usual way (Figure 11).
The seventh system (Figure 12) is used in locations where air conditioning is not used such as the Pacific Northwest. A fully-ducted heat recovery ventilator (HRV) or a fully-ducted energy recovery ventilator (ERV) provides balanced ventilation. Heating is provided by a radiant heating system. The HRV/ERV extracts air from the bathroom(s) and supplies air to the bedroom(s). Again, as with all the previous systems, a vented kitchen range hood is ducted separately to the exterior and is interlocked with a separate make-up air fan.
Figure 12 – Seventh System – Used in locations where air conditioning is not used such as the Pacific Northwest. A fully-ducted heat recovery ventilator (HRV) or a fully-ducted energy recovery ventilator (ERV) provides balanced ventilation. Heating is provided by a radiant heating system. The HRV/ERV extracts air from the bathroom(s) and supplies air to the bedroom(s). Again, as with all the previous systems, a vented kitchen range hood is ducted separately to the exterior and is interlocked with a separate make-up air fan.
Yes, architects, I know, I know. Lots of penetrations in the walls (Photograph 4). Get over it. You want energy efficiency? You want a controlled indoor environment? You want to build tight and ventilate right? You better get used to living with the holes. Putting the stuff on the roof or at the bottom of the building does not work. Might work in houses and row houses and town houses but not in apartments.
Photograph 4: Lots of Penetrations – You want energy efficiency? You want a controlled indoor environment? You want to build tight and ventilate right? You better get used to living with the holes. Putting the stuff on the roof or at the bottom of the building does not work. Might work in houses and row houses and town houses but not in apartments.
Are we done yet? Nope. Let me talk about insane and insulting to ones intelligence. There are currently no provisions in any US codes or standards that recognize the benefits of balanced systems with mixing and distribution. Balanced systems with mixing and distribution do much more with less air than exhaust systems without mixing and distribution. There should be some reward and punishment here.
Actually, there is. We reward the exhaust systems without mixing and distribution and punish the balanced systems with mixing and distribution because we treat them the same. It is pretty clear that ASHRAE is incapabable of fixing this based on the current antics of the ASHRAE Standard 62.2 Committee. But I have hope for RESNET and both the IRC and the IBC. Stay tuned. It is going to get worse before it gets better. But better will happen. Just not easily and not without pain.
- Leaky single family detached houses with small exhaust flows with undersized air conditioners and poor solar control with black shingles and poorly insulated ducts located in vented attics – the types of houses that we encourage people to build……Exhaust-only ventilation no longer works in new single family detached because we now codify “tight” and test for it.
- Following ASHRAE Standard 62.2 results in higher air change when a balanced ventilation system is compared to an exhaust-only ventilation system. It gets worse. RESNET procedures result in rating points hits when balanced systems are used as compared to exhaust only systems because RESNET references ASHRAE Standard 62.2. Builders and raters are not stupid…both are “gaming the ratings system” and exhaust ventilation becomes the obvious choice. RESNET stands for “Residential Energy Services Network” and is responsible for the Home Energy Rating System (HERS) index.
- Don’t talk to me about recirculating range hoods…those are like toilet bowls that never flush swirling stuff round and round…..
- Author: Leo Tolstoy, first published 1869, paperback 1,440 pages.
- Just putting a hole in the wall does not work – especially in the hot humid south – every a/c supply grill between the hole and the exhaust hood is going to sweat as the make-up air finds its way to the hood. And you have to figure the control thing out… Most of the time I do not precondition – or if I do I just mix it with air already in the space to temper it.
CMHC (2005). “Assessment of Suite Compartmentalization and Depressurization in New High-Rise Residential Buildings”, Research Highlight, Technical Series 05-112, October 2005.
Finch, G., J. Straube and C. Genge (2009). “ Air Leakage Within Multi-Unit Residential Buildings: Testing and Implications for Building Performance”, 12th Canadian Conference on Building Science and Technology, Montreal, PQ, October 2009.
Handegord, G.O., (2001). “A New Approach to Ventilation of High Rise Apartments” Proceedings of the Eighth Conference on Building Science and Technology, Ontario Building Envelope Council, Toronto, Ontario, February, 2001.
Lstiburek, J (September 2015). “BA-1507: Ventilation Guidance for Residential High Performance New Construction – Multifamily” Building Science Corporation, http://buildingscience.com/documents/building-america-reports/ba-1507-me…. September 17, 2015.
Ricketts, L., J. Straube (2014). “ A Field Study of Airflow in Mid to High-Rise Multi-Unit Residential Buildings”, 14th Canadian Conference on Building Science and Technology, Toronto, October 2014
Rudd, Armin (August 2013). “BA-1310: Supplemental Dehumidification in Warm-Humid Climates”. Building Science Corporation, http://www.buildingscience.com/documents/bareports/ba-1310-supplemental-…. October 22, 2013.
Innovative Dehumidifier Systems will be at the 2016 ACCA Conference & IE3 Expo in Charlotte, NC from March 10-13, 2016. Please visit Ron Revia and Brian Smith at booth 1101 to learn more about our Energy Star® Certified IW-25 dehumidifier. They will be discussing industry best practices and new technology designed to prevent and resolve microbial growth in multifamily housing.
In 2010, Brian Smith (a licensed general contractor) and Tom Honeycutt (a long time developer/owner) began a search for a standalone dehumidifier with adequate capacity, that could be easily and affordably installed in a standard stud cavity, was quiet, relatively tamper proof and could be used for new construction or retro-fit applications. Basically, units as unobtrusive as an HVAC return in a wall that could be set to a certain desired humidity level and forgotten about by the occupants. Unable to buy what met their needs, they decided to come up with a design that met the specific needs and get it manufactured.
The Energy Star® Certified IW-25 is the only in-wall dehumidifier engineered for multi-family units readily available for purchase and installation. It runs independently of HVAC systems and a humidistat hidden behind a tamper-proof cover. The unit can even be hardwired into existing electrical and piped into plumbing for a truly hands-off dehumidification system.
At ACCA 2016 and the IE3: Indoor Environment & Energy Expo, contractors—large and small—gather to see what’s new, make connections, and share ideas. Every year, the ACCA Conference brings together indoor environment and energy professionals for four days of learning, buying and selling, networking, and fun. Innovative Dehumidifier Systems looks forward to the opportunity to meet with those in the indoor environmental and energy services contracting industry.
The Aspen Mini Blanc is an aesthetically pleasing mini condensate pump that will surface mount next to the IW-25 dehumidifier. The ‘ultra quick fit’ Mini Blanc is designed to be fitted beneath high wall indoor units and offers easy access for future maintenance. The Aspen Mini Blanc operates on a float switch mechanism which detects the presence of water in the drain pan, activating the pump. This mini pump is powerful, quiet, and reliable. Plus the safety connections from the IW-25 dehumidifier will shut the mini pump off. Removing condensate water through gravity will often have very limited aesthetical solutions, as tubes leading the condensate water away into a suitable drain can often not go very far distances. Leading one of these tubes outside to drain out of the building can damage your walls and look very unappealing!
The Aspen Mini Blanc will solve this problem because you no longer rely on gravity, but can pump the condensate water to drain anywhere! Advantages of using a condensate removal pump:
- no slope/gravity required
- ultimate flexibility
- works in tight spaces
- aesthetically pleasing
- cheaper and faster installation
- no external impact on the building
- low failure rate
Lead all the water away into a suitable drain, efficiently and effectively removing condensate water without anyone knowing.
For more information on the Aspen Mini Blanc visit https://www.aspenpumps.com/en/mini-blanc.html
Seldom does a day go by that there isn’t a report of apartment mold somewhere in the US resulting in property loss or damage, serious health effects and legal implications. A quick search of Google News for “apartment mold” returns 20,600 results with numerous reports from across the country made within the past week.
While working with hundreds of developers, property managers and design consultants over the past few years, it has become apparent that a singular explanation as to what causes mold in apartments does not exist. There is universal agreement however, that the presence of mold results in lost revenue, remediation costs, bad publicity, health issues and potential legal consequences.
Moreover, the lack of a common understanding relative to what causes mold often permeates the media, government building officials and even the court systems. This article is intended to provide a basic understanding of what causes mold in apartments.
Estimates for moisture and mold-related residential failures in the United States now range in the billions of dollars annually. At the center of the debate is the issue of responsibility between landlords and tenants. By educating both landlords and tenants, we can eliminate excess moisture, maintain healthy apartments and keep mold growth outside apartments where it belongs.
In summary, you need to know the following:
- A mold problem is ALWAYS an excess moisture problem
- Excess moisture can originate from leaks, ventilation and occupant activities such as cooking, cleaning, showering & even breathing
- Leaks (weather or plumbing) are the result of a building failure and must be corrected immediately – responsibility for leaks usually falls on the landlord
- Water is in the air – the amount depends on various factors. The principles of water vapor are typically poorly understood by landlords and tenants.
- Maintaining appropriate levels of moisture (water vapor) inside apartments is the responsibility of both the landlord and the tenant.
In cases involving water leaks, tenants should promptly notify the landlord that water is leaking into the unit. By doing so, the tenant is acting to protect the structural integrity of the dwelling while preventing the growth of mold that will likely result from leaks that are not reported or repaired promptly. More frequently than physical leaks is the presence of excess moisture in the air (high relative humidity). A common example might be unwanted condensation on windows.
Moisture which has accumulated on window sills may leak into wall cavities causing hidden mold growth on wood and paper backed wallboard. The concept of condensation is important. Condensation occurs when moisture suspended in the air (water vapor) “condenses” into liquid water on a cool surface. The surface temperature at which this occurs is known as the “dew point” temperature. Dew point can be controlled by controlling BOTH room temperature and relative humidity (RH).
Chronic excess moisture in apartments will result in mold growth. In order for mold to grow the following four factors must be present:
- Mold Spores
- Organic Materials (food source)
Mold spores are naturally occurring and present everywhere. Nearly every surface of an apartment and its furnishings are covered with microscopic mold spores which are unavoidably introduced through door openings, human or pet transfers and ventilation. Mold spores lie dormant until moisture activates growth. As long as moisture is available, mold will continue to grow expanding from one surface to another. The proliferation of mold causes damage to property and results in negative health consequences. Organic items (food source) include furniture, clothing and construction materials.
Moisture is the only one of the four factors that can be sufficiently controlled. Temperature control is affected by mechanical limitations, ambient environment and tenant preference. Oversized HVAC systems are common in multifamily housing properties. It is important to note that conventional air conditioning systems operate based on sensible (temperature) input. Water vapor removal by air conditioning systems depends on how long the air conditioner runs and is secondary to the primary function which is temperature control.
A good example of this scenario would be senior housing properties. These apartments are typically smaller than the average family housing unit. The smallest conventional split air conditioner supplies 18,000 BTUs of cooling (or 1.5 tons) which may be more cooling than is required. For many senior apartments this means the tenant is forced to decide between “overcooling” and setting the thermostat to a lower temperature in order to adequately dehumidify. More often than not, the senior occupant will choose not to run the air conditioner resulting in excess moisture and in some cases mold.
Another factor to consider is high performance design. Trapped moisture has become the unintended consequence of tightly constructed, energy-efficient buildings. While tighter building envelopes drive down the sensible cooling load and save energy by reducing air conditioner run time, they also trap excess moisture inside apartments. In a tightly sealed apartment, moisture accumulates from normal occupant lifestyle activities. As stated earlier, conventional air conditioners do not operate based on water vapor content or relative humidity. The typical apartment HVAC system serves only one purpose, to raise or lower temperature. When mold shows up in apartments, it isn’t the heat, it’s the humidity.
7 Tips to Prevent Mold in Apartments
To prevent excess relative humidity and mold growth:
- Do not use ventilation when outdoor dew point is above 55.
- Make sure the clothes dryer is vented properly.
- Cook with lids.
- Do not dry clothing on indoor clothes lines or racks.
- Reduce water vapor by using effective bathroom, kitchen, and utility room exhaust fans above common sources of moisture. Verify exhaust fans are actually moving air (hold a tissue below vent to check air flow).
- Confirm appropriate indoor relative humidity level using a reliable digital thermometer/hygrometer.
- Keep relative humidity below 60 percent at all times and use a dehumidifier if necessary.
Using a stand-alone dehumidifier is the most certain way to ensure appropriate levels of relative humidity at all times inside apartments. Whole house dehumidifiers are appropriately sized for larger, single-family dwellings. While they will adequately remove excess moisture from apartments, common complaints include excessive noise and heat displacement as well as lack of operational control. In many cases whereby a tenant elects not to operate the air conditioner, they are unlikely to operate a dehumidifier either. Whole house units are also controlled by a wall mounted dehumidistat, similar to thermostat. Additionally, many whole house dehumidifiers are installed in conjunction with the exiting HVAC air handler which requires integration into the mechanical system. Installation of these systems usually require a licensed HVAC technician.
While less costly, portable dehumidifiers present other types of challenges when attempting to control humidity inside apartments. They are inconvenient, may require manual emptying and also rely on tenant cooperation to operate. In many situations it is impractical to expect tenants to operate dehumidifiers. Currently there is only one dehumidifier specifically designed for apartments available in the US, the award-winning IW25 dehumidifier by Innovative Dehumidifier Systems.
The IW25 places apartment humidity control directly in the hands of landlords. It has a tamper-proof cover that can only be removed using a special tool. The IW25 can be quickly installed inside an interior wall between existing studs. Once installed, it operates independently of the HVAC system to quietly and efficiently remove excess moisture from inside apartments.
For landlords and tenants who are searching for a cost-effective and efficient solution to prevent mold in apartments, the IW25 makes a lot of sense.
 Moisture Science 101, Dan Welkin; https://www.acca.org/wp-content/uploads/2014/01/Welklin-Class-notes-Moisture-Science-101.pdf
 A Brief Guide to Mold, Moisture and Your Home, United States Environmental Protection Agency; https://www.epa.gov/mold/preventionandcontrol.html
VHDA recently proposed changes to the 2015 Low Income Housing Tax Credit Qualified Allocation Plan (QAP) including a $1500 upward adjustment of cost limits per unit if all apartments are equipped with electrical and plumbing hook-ups for a hard-wired dehumidification system.
This is exciting news for Virginia tax credit developers. The expectation is several states will soon follow Virginia’s example. Many property owners and managers nationwide are struggling with excessive internal humidity and moisture as the unintended consequences of building tighter apartments and meeting building performance design standards.
Our AWARD WINNING in-wall dehumidifier, the IW-25-1, is currently the only solution available that was engineered and designed specifically for apartments. This makes the IW-25-1 ideal for developers who intend to take advantage of the additional $1500 allocation.
Prior to the introduction of the IW-25-1 by Innovative Dehumidifier Systems, owners trying to solve indoor air issues and prevent mold were forced to choose between ineffective portable units or expensive ducted systems. Click on the image below to watch a short video and see how the IW-25-1 compares.
If you are a developer who wants to take advantage of the new Virginia incentives or a property manager who wishes to take a more proactive approach to preventing mold in apartments, contact us today. We would be happy to collaborate with your design or maintenance team to show you how our solution fits into your long-term strategy. Call us today at (910) 579-3348.
The IW-25-1, In-Wall Dehumidifier was engineered specifically for multi-family applications to overcome the effects of increased energy codes, tighter construction and occupant driven internal moisture generation. It is an award-winning solution with unique tenant lock-out features allowing property owners to mitigate excessive humidity and prevent mold growth in apartments.
Prior to the introduction of the IW-25-1, property owners were forced to choose between ineffective portable units and loud, over-sized whole-home systems with wall-mounted humidistats that allowed tenants access to unit controls. Click on the image below to learn more…
In a head-to-head battle with the unrelenting South Florida humidity, the IW-25-1 by Innovative Dehumidifier Systems leaves the ring as the undefeated champ posting yet another unanimous decision. Wireless monitoring equipment was placed inside an upscale Ft Lauderdale area apartment where excessive humidity has caused a myriad of problems over the past few years. The equipment compiled temperature and relative humidity (RH) data over a period of ten days between August 1, 2014 and August 11, 2014. A sensor placed outside to measure ambient conditions revealed temperatures ranging between 76 and 88 degrees along with relative humidity in excess of 90% for a significant portion of the study.
For the three day period prior to the operation of the IW-25, relative humidity inside the dwelling ranged in the low to mid-seventies while maintaining an air temperature of between 72 and 73 degrees. Within a couple hours after the IW-25 was started, the inside relative humidity was driven down to the mid-fifties where it remained steady over the remainder of the 10 day testing period. Most experts agree that in order to prevent mold in apartments, the relative humidity should be maintained below 60 percent.
The IW-25 recently won the People’s Choice Award at the Product Marketplace at the American Institute of Architecture National Convention and Design Exposition. Boasting an affordable price point along with quiet and efficient operation, the in-wall dehumidifier is quickly becoming a popular choice for design professionals and property owners trying to resolve excessive humidity issues and prevent active mold before it starts.
Current plans for the IW-25 include September trips to Richmond, VA for the Virginia Housing Conference and Savannah, GA for the Georgia Affordable Housing Conference. In October the IW-25 will make appearances at the North Carolina Housing Conference in Raleigh and the Virginia Governor’s Housing Conference in Norfolk. Additionally, the IDS staff will be on hand at the AHR Expo in Chicago in January 2015. For more information on this study or the IW-25 please contact Innovative Dehumidifier Systems at 1-910-579-3348.
Innovative Dehumidifier System’s IW25 was recently highlighted on the Wilmington, NC ABC affiliate website and news. They were interested in highlighting how our product recently won the National AIA People’s choice award for innovative new product of the year, based on how our in-wall dehumidifier is used to help property owners control humidity and mold.
See the link below for additional details: