A Guide to Inline Blowers

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Last updated: 
February 1, 2016

You probably already know how important clean and fresh air is. But do you know how important air circulation inside the house is? Every year we seem to be adding more and more padding to our houses, in an attempt to insulate them against the cold. This we do, of course, in order to lower our heating and electricity bills, but over-insulating the house also means it becomes air tight. Thusly, air will not able to circulate well enough or at all between the inside and outside of the house. Stale air can lead to health problems such as asthma and allergies but, fortunately, there is a simple solution – ventilators. They are especially important in bathrooms and kitchens where moisture and humidity levels are very high and accumulate quickly.

Guide to Inline BlowersA very efficient, healthy and flexible option when it comes to ventilation is inline blowers. They exhaust all the moisture, steam and bad odors and keep your house healthy and aerated. Here is a guide to in line blowers, complete with all the questions you always wanted answered about them.

What is an inline blower?

It’s basically a big fan, located inside your ventilations systems, normally in your kitchen or in your bathroom. When inside the kitchen it’s usually placed in the range hood exhaust, meaning directly inside the ducting or conduit line that drives all the air outside.

Are inline fans quiet?

If installed correctly, they can be very quiet. But the real sound problem comes from the outside ones, like the ones you have in your garden for example, which are the loudest. However, you can use a few tricks to quiet them down, such as:

  • Placing them inside a cardboard box. This might not sound like much in theory, but when you put it in practice you will notice the difference. If you have the time for it, you can even build the blower a wooden and insulated box. You won’t even notice it’s there anymore. Remember one side of the box needs to always remain open. It’s best to look for tutorials online.
  • Attach a speedster to your fan. It’s a speed controller, which will allow you not only to quiet it down, but also to be able to use a bigger one because of it. So instead of a 4in fan you could go with a 6in one, because the sound, which is now completely in your control via the speedster, will be much more toned down.
  • Use a duct silencer. If you use it between the carbon filter and the fan itself you will indeed notice how the sound will reduce significantly. The silencers are lightweight, easy to use and have egg foam inner lining, which actually does all the noise reduction.

Do inline fans use filters?

Inline blowersYes, they do and it’s usually a carbon one. Carbon is the number one choice because it is best at filtering out impurities from both air and water based environments. So you can get normal or hydroponic ones, for, let’s say, your pool or backyard pond. They are made of extruded granular activated charcoal carbon and they eliminate chlorine, sediment, volatile organic compounds, the taste out of water and odors from the air. The filters are normally attached to the inside of the extractor fan.

What types of inline blowers are there?

Since technology and engineering have evolved so much lately, fans come in all shapes and sizes, for all purposes. But, to keep things light, they can be classified in a few major categories, as follows:

  • Axial and propeller fans – with the axial fans, the air flows parallel with the shaft. They are classified according to their wheel into C-wheel, which can be adjusted while the fan itself is running, they are small in dimension and have variable air volume; A-wheel, which can only be adjusted when the fan is standing still, small in dimension and adaptable as far as air volume goes; K-wheel, the blades are not adjustable at all.
  • Centrifugal fans, also known as radial fans have the air flowing in a radial direction relative to the shaft. They too are classifiable according to their wheel, as follows: F-wheel, with the blades curved forward and changes in pressure that have little influence on the pressure head; B-wheel, with the blades curved backwards, they are highly efficient, consume very little energy and their sound emission is low; P-wheel, with the blades straight backward, they are self-cleaning and their changes in pressure have very little impact on the air volume and the T-wheel, with blades that are straight radial. It is self-cleaning also and it’s the best suited one for transportation.
  • Combo flow fans, through which the air flows in both the axial and radial directions. The other difference is that they get a lot more pressure than the simple ones.
  • Cross-flow fans, through which the air flows inwardly and then outwardly, in a radial direction.
  • Ducted fans, which are used for aircrafts, such as planes and jets. They are electric in operation and have a higher thrust-to-weight ratio by design.

Are fans influenced by external factors?

Yes, they are. The biggest external factor that influences how inline blowers work is the air itself. The manufacturing conditions usually promise a certain delivery but, if the fan is working outside the Normal Temperature and Pressure conditions (NTP), it will not deliver the promised quality and you should have that in mind when operating it. Temperature and pressure vary because of the air’s density or because of location, meaning altitude or elevation above the sea level. Normal temperature and Pressure conditions mean 68°F, 9.92 inches Hg, 0.075 pounds per cubic foot.

Also, here are three pointers you should know about working your fan in relation to outside conditions:

  • The combination of hot air and low air density means that less air mass will be transported through the fan;
  • The combination cold air and high air density means more mass;
  • Equal speed and dimensions means that the volume of the flow will remain constant.

Uses of fans around the house and garden

Most people, when thinking of fans, they probably imagine those little white, round ones with three blades and one short leg, which you can put on the table to cool you down in the summer. And while that is completely true, there’s more to fans than that. Industrial, exhaust and inline blowers work magic around the house if you know where to place them. Here are some tips.

  • Inline blowers and fanIn the bathroom – installing an exhaust fan in here, even a small one, will protect the bathroom not only from unpleasant odors, but from moisture as well. This means that the walls won’t “sweat” as much, the air will be dryer, the moisture left after hot baths will disappear much quicker and it will keep the paint on the walls from peeling. It will also keep doors from warping and it will stop mold accumulating on all surfaces of the bathroom. Using a fan in the drier room works in the same way.
  • In the kitchen – as mentioned, these are exhaust fans as well, which help gather and release into the outdoors all the smoke, grease particles, fumes, vapors and bad smells that we usually associate with cooking. Kept active at all times, they can work miracles.
  • Indoor swimming pool, greenhouse, sunroom – if you have one of these at home, you might want to think about installing an inline blower. It will help reduce the unwanted heat, keep the moisture and steam away and allow you to have perfect control over the temperatures in there at all times.
  • Fans can also be installed into leaf blowers, as a duct booster fan to the machine’s capacity.

Which are the best commercial fans?

There is an entire range of brands that manufacture and sell very good fans. With this in mind, you should first think about your fanning needs, like how big a fan do you want, what is the size of the room you’re looking to ventilate, how much cubic feet of air do you need in there, what is the moisture situation or what is your budget for spending on a inline duct fan. After you’ve answered all these questions for yourself, you should do some research and see which companies sell the fan closest to your needs and money possibilities, or, maybe, who offers them on sale. Here are some brands, so that you can make a comparison:

  • Panasonic and their ventilations are, probably, the leader in the industry; out of all the fans they produce, an outstanding one is the WhisperLine inline fan, with easy installation, extractor, very quiet working and adjustable airflow control;
  • Fantech USA – they offer a wide range, including axial, residential, commercial and power roof ventilators;
  • Greenheck – they offer cheap fans, dampers, louvers, kitchen ventilation hoods, and energy recovery and make-up air units;
  • Vent-Axia – which claim they produce the world’s quietest fan, complete with muffler, easy setup and a timer;
  • Vortex Fans – which offer fans, motors for DIY aficionados, accessories and all sorts of kits. While most fans are electric, some of their fans run on fuel.
  • Some other brands are: Elicent, an Italian one, NuTone, which sell a great bathroom upgrade kit, Suncourt, Broan, HVAC Quick, Hydrofarm and Lowes.

No matter what brand or type of fan you choose, make sure you install one in your bathroom or your kitchen. Clean and fresh air is very important and it’s never a matter than can be overlooked, especially in winter-time, when we make full use of our insulation and heat sources and keep our houses shut as tight as possible against the cold.

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