Blog Tag: outside air

If at first glance you think I misspelled the title of this blog and it should read “Sea Water” you are incorrect. This is about water in the form of water vapor or condensation that you often see on windows and where ever damp cold air comes in contact with a warm surface. When you “see” water condensing or water dripping from someplace it shouldn’t be you need to find out why.

One of the most common places in a home to find water in the form of condensation in on single pane windows or on walls or surfaces that are inside barriers for outside walls. Condensation forms when the dew point is relatively high…say 60 to 70 degrees and there is a lot of humidity in the air. Since warm air holds moisture better than cold air the condensation issue is usually found in the summer months. Although it can also be an issue in the fall or spring of the year.

One of the challenges with tight homes and office buildings is the limited amount of fresh, outside air that is introduced into the indoor environment. While constantly circulating the air with the HVAC  fan systems does keep the air moving,  it does little to keep the air from getting stagnant or reduce the indoor levels of  CO2. Introducing outside air, even small amounts over time, can be significantly help the occupied areas. However, if the outside air is hot or cool and humid, then the condensation issue can be a problem again.

Some of the newer variable speed drive, high efficiency HVAC systems incorporate a de-humidification function that allows the cooling coils in the air handler to get really cold during the AC cycle prior to turning on the air handler fan. This allows for more removal of the moisture that may be introduced as outside, fresh air through the HVAC unit.

One of the main reasons for minimizing the amount of “indoor” moisture is to reduce or eliminate the potential for mold growth. There are two main “needs” for mold to grow. Water and a food source. Take away either one and you will significantly reduce the chances of mold growing in the indoor environment. So when  you see water in the form of condensation on the windows in your home or office you can be fairly sure that there is moisture forming in other parts of the indoor structure. And….where there is water there is mold.

Pure Air Systems has been making HEPA and Carbon based fan powered air filtration systems since 1985. These units can be attached to  and HVAC system or used as stand-alone units in residential, commercial, institutional or industrial applications. For over 25 years PAS has used their units to introduce small amounts of outside air that is first past through the HEPA units then into the HVAC units. Since the PAS units are mixing small amounts of outside air (usually 50 to 80 CFM ) with large amounts of warm, unfiltered return air ( usually 300 to 800 CFM) there is little chance for moisture to occur.

This process has been used thousands of times since we first introduced the systems and has been very effective at not only cleaning all the air in the homes up to 48 times a day, but provide for some fresh air without the potential for adding moisture or inviting mold growth indoors.

For more information on the complete line of HEPA and Carbon based air filtration systems please go to our website at: www.pureairsystems.com. Or call us at: 800-869-8025.

When we hear the term “fresh air” we often think about being outside next to the ocean feeling the breeze or on top of a mountain breathing the cool, crisp air. Or, when you are stuck indoors in a building or home for long periods of time you might say, “I’m going outside to get some fresh air.” If we really believe the air is better outside, why do we spend so much time indoors? And, more importantly, what is fresh air?

In reality the term “Fresh Air” is really a misnomer. While it is true that air outdoors is not prone to have that “stale air” smell you have indoors due to lack of ventilation, the levels of airborne contaminants and gaseous molecules outdoors is often not any lower. Yes, that is correct. Depending upon where you are outdoors the levels of harmful airborne particulate and gaseous pollutants can be extremely high.

You already know that during the spring and fall of the year various grasses, weeds, trees, etc. produce pollen of all sorts creating significant allergic reactions and health problems. Is this fresh air? You are outside…aren’t you? Or if you are in a downtown area of a large city you can sometimes feel some stinging in you eyes and throat. That’s usually caused by the high levels of gases such as nitrogen oxide, carbon monoxide, sulphur dioxide and hydrocarbons from all the vehicles. Of course you also have all the airborne particulate that is produced by tires grinding dirt into sub-micron particles. So now that we have identified fresh air let’s take a look at the process of using outside air for ventilation and reduction of CO2 in homes and buildings.

Pure Air Systems has been manufacturing HEPA and Carbon based fan powered, commercial grade air filtration systems since 1985. These units were not only designed to filter the air in a room, home or commercial facility but also to concurrently introduce small amounts of outside air and filter that air prior to introducing it to the indoor environment. As we mentioned before, the term fresh air is really a misnomer. Unless the outside air source is filtered prior to mixing with the indoor environment, it is not fresh air.

The PAS product line is capable of introducing high percentages of outside air that is filtered by three different medias. First there is a polyester dual-layer ring panel filter that is designed to take out the larger particles. Second the carbon media removes many of the odors and gases. Third, is the HEPA filter itself which is a certified HEPA rated at 99.99% removal of all particles 0.3 microns and larger. This three stage filtration ensures that any outside air will be in actuality, “Fresh Filtered Air.”

So the next time you hear the term fresh air remember there are levels of fresh air and you need to make sure that you use the right filtration process to ensure you and your family are breathing fresh air.

For more information on this concept and the complete product line offered by PAS please go to our website at: www.pureairsystems.com. You can also contact us on Facebook and Twitter.

For those of you that live in the northern parts of the US, you know that when summer turns to winter, the air gets much drier. The reason is that cold air holds much less moisture than warm air and as a result the cold winter air is much drier. This also means your are shifting your environmental control system from cooling (removal of moisture and cooling the air) to heating ( heating the air).

When you heat the air using your forced air ducted heating/cooling system you remove what little moisture is in the air. The result is a much dryer environment; dry noses and sinuses and the inevitable static build up. The drier air also play havoc with wood furniture.

This warm dry air also increases the levels of airborne particulate since there is no moisture in the air (water molecules) to attach to the dust particles and make them heavier than air. Therefore you are subjected to more dust particles in the winter than in the summer. Add to the fact that windows and doors are seldom opened in the winter, and you have an environment that gets little to no fresh air or outside moisture for months at a time.

One way to minimize this dry air problem is to add some moisture to the indoor air. This is often done by using a humidifier; either attached to the supply side of the HVAC duct system or the use of a portable humidifier. The challenge, however, is to introduce the correct amount of moisture. If you add too much moisture you will get condensation on the windows. It is difficult to maintain the correct humidity levels.

Another way to introduce moist air and maintain a cleaner indoor environment at the same time is to use the whole-house HEPA air filtration systems manufactured by Pure Air Systems. These unit are fan powered and designed to mate to any forced air, ducted heating/cooling system. Not only will these three-stage filtration systems remove harmful airborne particulates and odors and gases but they are also capable of introducing small amounts of outside filtered fresh, moist air.

The 600HS, 1200HS and 2000HS series of HEPA filtration systems have the ability to introduce 50 to 200 cfm of outside air and mix it with the return air and filter it before it is introduced into the HVAC unit. By adding a 6″ or 8″ duct from the outside (preferably from an area just below the roof line) to the selected PAS HEPA unit, you can bring in some of the more moist outside air and increase the moisture in the house naturally.

Even if the outside air temperature is below freezing you are only adding a small amount of air (usually less than 5% of the total HVAC volume) and the cold air is mixed in the HEPA unit with the return air that is also coming into the HEPA unit. The result is an addition of moisture introduced at the ambient air temperature of the home.

For more information on the complete line of Pure Air Systems HEPA based and media based filter systems please go to our website at: www.pureairsystems.com

In a few areas of the US the weather is mild enough that one can open the windows and allow some air to enter the house from the outside most of the year. For the rest of us opening the windows is only an option for a few weeks out of the year as the heat, humidity and cold temperatures limit our ability to add any outside air to the home.

You’ll notice that we use the term “outside” air rather than “fresh” air as most often the outside air entering the home or occupied facility is anything but fresh.

Because of industrial pollution, cars, trucks, farming, construction, grasses, weeds, pollen, decaying matter and a host of other sources, the air outside has a high concentration of small, less than 10 micron, particulate matter and a wide variety of gases and odors generated by auto emissions, pesticides, chemicals, etc.

So, when you open up your windows to let in some “fresh” air to eliminate the “stale” air, you are actually doing a good job of exchanging one problem for another. So, in order to actually introduce fresh air you need to filter the air as it enters the house. Okay, so how do I accomplish this?

Actually this is not difficult to do. Most homes have a ducted, forced air heating/cooling system which moves air throughout the house and normally has a furnace filter or filtering device located on the return air side of the fan section of the unit. This filter keeps the air handler clean by removing dust and dirt from inside the home.

Simply by adding a 6″ or 8″ diameter duct from outside the house and attach it directly into the main return air duct at the air handler section you can introduce as much as 100 to 150 CFM (cubic feet per minute) of outside air and have it all filtered prior to entering the house.

Using this approach allows you to add a much smaller amount of outside air and is more effective than opening up windows. The HVAC  fan will move the air throughout the house in a very short period of time and mix it with the existing air. By using  just 100 CFM you will add up to 144,000 cubic feet of air in a 24 hour period or enough to change all the air in a medium sized home 1.2 times per day. The more air you add the higher the exchange rate.

Also, adding a small amount of outside air ( 100 CFM) to the return air duct will not affect the conditioned environment of the house. Since most air handlers move 1200 CFM to 2000 CFM, adding 100 CFM of hot, cold or humid outside air is less than 10% of the total volume of air being conditioned.

Pure Air Systems has been using  the concept of adding outside filtered fresh air to homes, offices and other occupied areas since it’s beginning in 1985. This concept, used in concert with the HEPA air filtration systems and air filters manufactured by PAS, has been proven to be extremely effective in thousands of applications across the US and Canada.

In fact, Pure Air Systems pioneered the use of adding outside air with the introduction of its 600HS unit in 1985. Since then the concept of adding outside air has been used with all the HS series units. In addition to filtering out the contaminants this concept will, in many cases, actually slightly pressurize the air in the house, office or occupied environment minimizing the entry of outside contaminants as well.

For more information on using outside filtered fresh air go to our website at: www.pureairsystems.com.