Wednesday, February 1, 2017

Is your ventilation under pressure it can’t handle? Static Pressure Explained

While it might not be the pressure of needing to hit the game winning shot with 0 seconds left in the championship game, our exhaust fans are under a different pressure to perform – Static Pressure.

The dictionary defines it as: The force per unit area that is exerted by a fluid upon a surface at rest relative to the fluid. If you are like most people, that doesnt really clear it up – especially when it comes to ventilation. I thought we are moving air not fluid? The very basic definition is how much pressure is exerted to move a given amount of fluid a defined distance. For airflow (ventilation measured in Cubic Feet per Minute – CFM) that means how much CFM is needed. For instance a fan might move 100 CFM at 0 of static pressure. When the static pressure is increased to 0.1 the same fan might only move 90 CFM.

Okay, the advanced physics lesson is over, lets take a look at what all this means. It can be summed up as, the higher the static pressure, the harder the fan needs to work. When it comes to exhaust fans, there are many contributing factors that can negatively affect the static pressure of the system. As you are determining what type/size exhaust fan you will need, these are some of the factors that need to be taken into account:

Duct size: This is a case of bigger is better. The wider the duct, the easier it is for air to flow through it. Think of one of those small coffee-stirring straws. Try to blow as much air as you can through it. Have you turned red yet? Now take one of those large milkshake straws and exert the same amount of energy blowing air through it. Not even a comparison. This is exactly what is happening in your system when you use smaller diameter ducting. The smaller the duct size, the more force you will need to overcome the static pressure created. This is multiplied if you are reducing the size of the duct coming from the fan to match the rest of the system. For instance going from 6 to 4 will have a big impact.

Duct Length: Lets stay with our straw illustration. Take 20 straws and put them together. You will notice you can still get some air through them, but once again, it takes a lot more effort. A shorter duct length will create less static pressure.

Twists and Turns: Each time you add an elbow or turn in the ductwork, you add more static pressure. Its been working so far, so lets stay with the straw. Now take the straw and bend it into 10 different twists and turns and try to blow air trough it. Each time you add a twist, it will get harder to move air through it.

Great, we now know about Static Pressure, but what’s the big deal. As we learn more about indoor air quality and the benefits of proper ventilation, it is vital that the systems are working as expected. As we saw in the above example if the home calls for 100 CFM of ventilation but because of the static pressure in the system, we are only getting 90 CFM or worse, we have an issue. In extreme cases you might only be getting a fraction of the airflow you thought. This can lead to moisture issues like mold and mildew.

To learn more about ventilation, visit www.airkinglimited.com

Monday, January 16, 2017

Bad air out, fresh air in – bringing fresh air into your home

When you hear the term Fresh Air, it might invoke thoughts of a warm summer breeze, a walk on the beach, or that first smell of spring after a long winter.

When it comes to your home, it is much more than that. Fresh air is a vital part of maintaining Indoor Air Quality (IAQ). Bringing fresh air into the home can be as simple as opening doors and windows and letting it happen naturally. The challenge is that opening doors and windows is not always practical. That is where other solutions come into play.

Lets first take a look at why it is important to have fresh air coming into the home. Not to try and scare you, but your home is full of pollutants that are negatively affecting the air you are breathing. Something as simple as you breathing is producing CO2 gas. Add in cooking (especially on a gas range), cleaning or using almost any appliance and the air quality can quickly deteriorate. Brining fresh air in is as simple as exchanging the stale (bad) air in the home with new (fresh) air from outside the home.

Now back to how to do this. We already talked about windows and doors and the limitations they have. Another option is using what is known as a mechanical solution. With a mechanical solution such as the Air King model QFAM, fresh air is brought into the home with a fan. There are a large variety of mechanical solutions on the market and they all have their pros and cons. HRV and ERV units are good, but expensive to purchase, install and maintain. Simpler solutions such as small fans that bring air in can work, but the air is not conditioned or filtered. Depending on the location or day, sometimes the air coming in might be worse than the air inside (high pollution areas or days). It is best to look for a solution that provides air filtration (filters that can be easily accessed and changed) as well as some type of humidity and temperature control that doesnt allow extreme cold, warm, or humid air into your home.

From a homeowner standpoint, do the simple things – open doors and windows when you can, utilize your exhaust fans and range hood. Consult a HVAC expert to walk through the best solutions for your specific home. To learn more about fresh air solutions from Air King visit http://www.airkinglimited.com/page/qfam-fresh-air-machine.html

Monday, January 2, 2017

Turn up the exhaust – using a two-speed exhaust fan

Over the past several year’s indoor air quality (IAQ) has become a major focus when it comes to residential homes. We continue to gain knowledge regarding the air we breathe and the effects it can have on us. Properly ventilating the home is at the forefront of creating a quality living environment.

A newer trend in residential home ventilation has been the usage of two-speed exhaust fans. Lets take a look at exactly how a two-speed exhaust fan operates. The exhaust fan has a low speed that typically runs continuously at a very low sound level to provide a constant air exchange in your home. You probably won’t even be able to tell the exhaust fan is operating. Studies have found that by exchanging the air of your home (exhausting the stale, contaminated air inside the home and bringing in fresh air from outside of the home) multiple times per day will increase your indoor air quality. There are also national building codes that require a certain number of air exchanges per day depending on the size and occupancy of your home.

While the low speed provides the amount of airflow needed for the daily air exchanges, when the bathroom is in use you typically need a lot more power. This is where the high speed comes in. The high speed will generally be two to three times that of the low speed and provides the power you need to properly ventilate the bathroom when it is in use.

There are multiple ways to control how the exhaust fan switches from low to high speed. The most common is a wall switch, but there are also automated solutions such as motion sensors or humidity sensors that when activated (either by someone entering the room or a rise in humidity) will turn the exhaust fan to high speed.

When choosing a two-speed exhaust fan, you want to take into consideration items such as where it will be located, the sound level and how you will switch from low to high speed. To learn more about two-speed fan options from Air King’s visit www.airkinglimited.com.

Friday, December 16, 2016

Duct it right – how to properly duct your exhaust fans


You did your homework, picked the perfect exhaust fan for your room and are now ready to install it. You have now entered a make or break crossroads in the installation process - how are you going to connect the ducting to the fan.

Okay maybe that is a bit dramatic, but the ducting is a key element to the installation process. There are basically two scenarios you will be faced with, existing ducting and new ducting. If you are replacing an old fan, there is probably ducting already in place. It is very important that the ducting be the same size as the new fans duct collar. Many older homes utilized 3 or 4 round ducting. Many newer fans are utilizing 6 ducting. Duct reducers are available to make the transition to smaller ducting, but this will increase the sound level of the fan and decrease the performance level – so that perfect fan you just bought, might not be so perfect after all. The best thing to do is to replace the ducting to match the size the fan requires.

With a new installation, you will need to run ducting anyway, so make sure it is the size required by the fan. It doesnt end there. You also want to use the shortest and straightest ducting possible. This allows the fan to perform at an optimal level. The longer the ducting and the more twists and turns, the less effective the fan will be. While rigid ducting is the best, if you need to use flexible ducting, make sure it is cut to length and as straight as possible. If the ductwork looks like some mythical sea creature, it is probably not an optimal installation. Each twist and turn builds up Static Pressure (SP), which causes the fan to work harder to push the air through. Think of blowing air through a large straw. If it is straight, its not all that difficult, but if you bend it a few times, it is a lot harder to blow air through it. Insulating your ducting will also help with any condensation issues. In colder climates, as the warm air passes though the cold ducting, condensation builds up and can actually cause water to come back through the ducting and into the room.

To finish the ducting installation, you want to make sure the air is making it outside of the home. The worst thing you can do is have air blowing directly into your attic or wall cavity. Air coming from a bathroom will most likely be hot humid air, over time that will build up in the form of mold and mildew. Making sure all seams are sealed is also critical. If air is leaking out of the ducting as it comes through, it is not making it to where it needs to go. Using a properly sized roof, wall or gable mounted cap will ensure that the air is going where it needs to go.

To learn more about exhaust fans and ventilation visit www.airkinglimited.com.

Thursday, December 1, 2016

Take it outside – Exhausting your fans outside of the home.


Youve read all the articles about proper ventilation and improving indoor air quality. You went out and purchased the perfect exhaust fans for your home and are now ready to install them. Good for you, great job. As you start the installation you realize that you will need to run ducting for these fans and there isnt any existing ducting. No problem, youll just run it into the attic, away from the living area. HOLD IT RIGHT THERE! We are going to need to stop you.

Making sure you exhaust the air outside of the home is one of the most important steps when it comes to ventilation. Even if you have existing ducting that you are connecting to, you want to confirm that it is running outside the home. If you are like most people, the first question is why, whats the big deal.

The most commonly mistaken place people run their exhaust fan into is the attic. Now stop and think about your attic. It is not the most pleasant place to begin with. In the summer it is probably very hot, even if it is properly insulated. Now take that hot area and add almost 100% humidity to it as the moist air from your shower is pumped into the space. Before long you will have what feels like a rain forest in your attic. This will quickly turn to mildew and then mold. Because it is an attic and not a common living space, it might be years before you detect that mold is growing (think of those renovation shows on TV where the host finds mold that has been growing for years – not a pleasant sight). Anytime you find mold growing in your home, it is not a good thing. All that can be easily prevented by just exhausting the fan outside the home through a wall, roof or gable mounted cap.

To learn more about ventilation visit www.airkinglimited.com.

Tuesday, November 15, 2016

Get ventilation sensitive – using a motion sensor with your exhaust fan


If you have spent any amount of time reading through our website or these blog posts, it is probably clear that we think (along with many organizations) that proper ventilation is a fairly big deal. A properly ventilated bathroom can benefit you and your home by removing odors and more importantly, humidity that can cause the build up of mold and mildew.

A big issue is that the fan needs to be turned on to be effective. There are host of reasons why it doesnt get turned on, but there is a way to override almost all of them – adding a motion sensor.

A motion sensor works by turning the exhaust fan on when it detects the room is being occupied. Once it no longer senses motion in the room, it will stay on for a preset amount of time and then turn off. It will run for longer than the room is occupied to make sure any residual steam or moisture from a shower is exhausted out of the room. The automation is the key part of this. There is nothing to turn on or off. This is especially great for rental properties where occupants might not be as diligent as you might want them to be with the ventilation of the home.

Adding a motion sensor can be done fairly easily. If you need to install a new fan or replace an existing one, there are many options that have a built in motion senor. If replacing the fan is not something you need to do, motion sensing wall switches are available. These simply replace the current switch the fan is wired to.

To learn more about integrated motion sensing fans or motion sensing wall switches, visit www.airkinglimited.com.

Tuesday, November 1, 2016

Get ventilation sensitive – using a humidity sensor with your exhaust fan


Thinking about how to improve your bathroom might not be something you spend a lot of time dwelling on and if you do it is probably how you want to replace the vanity, that new shower head or even how you are going to completely remodel. Even when you clean the bathroom, probably more thought goes into what a hassle it is and how much mildew is building up after just cleaning it.

While a complete remodel of the bathroom might be out of reach, there is a fairly simple upgrade you can make to your bathroom that will at least help with the cleaning process – adding a humidity sensor to your exhaust fan.

A humidity sensor will automatically turn the exhaust fan on when the humidity level of the room reaches a preset point and will stay on until it falls below that point. Here is how it works; you start the shower, which instantly raises the humidity level of the room so the fan turns on. After your shower, there will still be residual humidity in the room, so the fan will continue to run until that humid air has been exhausted out of the home. This helps prevent the build up of mold and mildew, both like warm humid environments. As an added bonus, it is all automated, nothing for you to do.

Adding a humidity sensor can be done fairly easily. If you need to install a new fan or replace an existing one, there are many options that have a built in humidity senor. If replacing the fan is not something you need to do, humidity sensing wall switches are available. These simply replace the current switch the fan is wired to.

To learn more about integrated humidity sensing fans or humidity sensing wall switches, visit www.airkinglimited.com.