Ventus – A Ventilation Story

When the typical person hears the word ventilation it can call to mind different pictures. For most it probably is thought of as a fairly new technology routed somewhere in the mind 1900’s. The fact that you are reading this blog probably means ventilation means exhaust fans and range hoods. You would not be wrong, but we are going to go a little deeper and look back through the ages at ventilation.

Let's start with the word “ventilation”. It comes from the Latin word ventilatio which has its root in the word ventus, meaning wind. In the ventilation field we use terms such as exhaust and air movement which at its root is wind (moving air).

Next, we’ll trace back to the origins of ventilation devices. It might come as a surprise that it can be traced back to thousands of years BC. As humans began to bring fire into the houses/structures they built to either heat them or cook with, it quickly became evident that they had to get rid of the smoke created. The first form of ventilation was a chimney. Archeologists have found examples throughout the years of chimneys being used. The earliest is probably in China approximately 4000 BC. Other significant finds include Roman homes that had a hole in the roof to direct smoke. Thousands of years later we are still using this same technology. A little updated to the times, but in essences the same basic principle.

Another milestone in the history of ventilation was in the 17th century. King Charles I of England recognized that poor ventilation was causing health problems and he decreed that the ceilings in homes must be at least 10 feet high and that windows must be higher than they are wide to allow for ventilation.

Skipping ahead a few hundred years and we come to the 1920’s/1930’s where modern ventilation was created. While chimneys were okay, they were not as effective as they needed to be. The solution was to add a motor to the chimney and force the smoke up and out of the home. This was the first range hood. With most homes now having indoor bathrooms and especially showers, the need for ventilation increased even more and the same technology was now being used in the bathrooms to exhaust steam and odors.

From that first range hood in the early 1900’s we have seen a lot of advancements in the ventilation field. Technology has allowed exhaust fans and range hoods to become more energy efficient, quieter and more effective. Recently even more emphasis has been placed on indoor air quality. Ventilation is a key component of good indoor quality and the more we continue to learn, the more we are finding that a properly ventilated home is a much healthier home. I guess King Charles I did know what he was talking about hundreds of year ago.

To learn more about indoor air quality or ventilation fans browse through the Air King blog or visit www.airkinglimited.com.

The Air Exchange

When you hear the term Air Exchange what comes to mind? Some picture a place like where you exchange your gas grill propane tank, some think of a returns department. Even those who have heard the term sometimes don’t fully understand what it really is. 

On the surface air exchange is a fairly simple concept. Taking the air inside your home and replacing it (or exchanging it) with fresh outdoor air. Not all that difficult to understand. The complexity comes in on how that is done. Lets first get an understanding of what an air exchange is.

Air Exchange is the number of times the air inside your home is replaced with fresh outdoor air. The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAR) recommends at least an air exchange every 3 hours. Exchanging air is typically done by having a continuous source of fresh air coming into the home while exhausting the stale air out. So far everything still seems fairly straightforward. Good air in, bad air out – easy. The challenge comes in calculating exactly how much. Bringing too much in and you put unneeded stress on your HVAC system. Not brining enough in and now your indoor air quality suffers. Here is where we need to do a little math. Not to worry, this is fairly simple math. If you have a 1,000 square foot home with 8-foot ceilings you have approximately 8,000 cubic feet of air in your house. Exchanging the air once every 3 hours will mean that you need to move about 2,700 cubic feet of air an hour. Now divide that by 60 (60 minutes in an hour) and you get approximately 45 cubic feet per minute (CFM).  That would be for a home that has zero natural air infiltration. To get a better picture of how much air is actually needed, we need to look at different types of homes.

Older, drafty home. If you have an older home that has drafts, the good news and the bad news is the same news. The good is that you have a natural flow of fresh air coming into your home. Engineers call this natural air infiltration – the rest of the world calls this a draft. The bad part of a drafty home is that you have no way of controlling the air and your utility bills are probably high. For these types of homes it is important that you are properly ventilating the home with bathroom exhaust fans and a kitchen range hood but typically you do not need any additional equipment to ensure fresh air is coming in. The amount of air coming in is going to naturally “push” the stale indoor air out. Adding insulation, sealing doors and windows and so forth can reduce the amount of drafts, which is a good thing, but keep in mind that you may need to add a mechanical solution to bring fresh air in.

The Goldilocks House. Not too drafty but not too tight. These homes are typically a few years old (10 to 20) or an older home that has been renovated. They have a good balance of natural air infiltration but not so much that they would be considered “drafty”. In these houses ventilation is important but you might also need to add some type of system to bring fresh air in. Calculating how much as we have mentioned above gets a little tricky. Using our 1,000 square foot home example we calculated that you need 45 CFM but if you have a natural air infiltration of 10 CFM now you only need 35 CFM. To determine these numbers you will need to consult an HVAC professional. They are able to run tests on your home to see what your true infiltration rate is.

The Tight Home. These are typically homes that have been built in the past 10 or so years to the higher building standards. They are called tight homes because there is little to no natural air infiltration. This is great for the heating and cooling cost, but not so good for indoor air quality and air exchanges. The good news is that building codes include provisions for a mechanical solution to exchange the air – venting the stale air out and brining fresh air in. There are a number of solutions that are able to do this without a noticeable impact on the HVAC system. It wouldn’t make sense to build a home to gain all the advantages of a tight home, then turn around and lose all of that because you need to bring fresh air in. One of the best systems on the market is either an Energy Recovery Ventilator (ERV) or a Heat Recovery Ventilator (HRV). Both “recover” the lost energy by tempering the air coming into the home.

To learn more about air exchanges and indoor air quality visit https://www.ashrae.org/

For information about exhaust fan options as well as ERV and HRV units, visit www.airkinglimited.com

Saving Energy During a Pandemic

As working from home and schooling from home continues to be the norm, a side effect can be higher energy usage and bills. Having two, three, ten computers running, every light in the home plus increased pressure on the HVAC system can quickly add up. Here are a few tips to keep the energy usage down.

Use LED Lights

With an increased need for lighting, it is even more critical that the most energy efficient types of bulbs be used. LED bulbs are over 75% more efficient than standard bulbs. Stop and think how many and how long your lights are on during a day, then think about how much you can save if they were LEDs. While switching to LED bulbs is a huge savings, turning off lights is even better.

Location, Location, Location

Typically you hear this term in the real estate business, but it holds very true when working and schooling from home. If possible choose a location in your home that has plenty of natural light. This will allow you to turn off the lights as we mentioned above. Another consideration is with many families converting spaces into offices or schoolrooms, it is important to be strategic on placement. Make sure not to cover up HVAC vents or returns that would cause the system to have to work harder. Shared spaces can be difficult, especially if interactive meetings are taking place. If possible, having everyone in one room can save energy by only needing to condition and light one room rather that multiple rooms throughout the home.

Use Portable Fans

In many cases, all that is needed to keep the room comfortable is either a portable fan in the warmer months or a portable heater in the cooler months. These use a fraction of the electricity that your HVAC unit needs. Air King and Lasko offer a wide range of residential and light commercial options.

Turn Items Off

If you have children, then you have probably at one point in your life (or every 10 minutes) walked into an empty room that has every light in that room turned on. No matter how many times you tell them to turn the lights off when they leave the room, there it is – every light still turned on. For sanity sake, just accept the fact that your job as a parent is to follow them around and turn the lights off. Turing lights off however are just one way to keep the energy usage down. Turning off other items such as computer and monitors when not in use can have a positive effect also. Most electronics nowadays have some sort of energy savings mode (sleep mode) but even in these modes, they are still using energy. Turing electronics completely off when not in use is the best way to save. Another consideration is once the workday or school day is complete, turn everything off and get away from them. This will save energy and give your eyes and body a break. How many times have you or your children finished a full day of online school or work meetings just to leave the computer and go right to the TV to binge watch the new series. Try going for a walk or having a cup of coffee outside (making sure to turn the lights off before you leave).

Washing

Being home most of the day can lead to some habits that could be costing you in energy usage. Things like doing laundry can have a large effect. There might be the temptation to do a small load of laundry each day instead of waiting for a full load. We absolutely get it that doing laundry for most people is not on the top ten list of enjoyable activities in the home. Doing smaller loads throughout the week instead of one big laundry day might be preferred but it will more than likely come at a cost of using a noticeably more amount of energy. Air-drying clothes will save a significant amount of energy. It will also get you out of the house and away from the screen. If you turn off the lights when you leave, you now have hit on multiple energy saving tips with one activity! Washing dishes is similar to clothes. A dishwasher’s energy efficiency is predicated on running full loads. Avoiding the temptation of running the dishwasher after every meal will save energy.

For more tips on how to save energy within the home visit www.airkinglimited.com or the ENERGY STAR® website at www.energystar.gov

What is a Net Zero Home

A trend in the building industry is towards Net Zero homes. The goal of a Net Zero home is to be able to provide all the energy needed for the home without using outside sources. An older term many used was “living off the grid”. When people hear that term, the mind can race to a picture of living in a tent in the middle of the Alaskan wilderness needing to forage for your food everyday. While that might sound like a fun adventure for a few days, for most of us we like the comforts we have. The good news is that Net Zero homes are designed to still give you all the modern day comforts just more energy conscience.

 

There are multiple components to a Net Zero home that are all designed to reduce the energy usage down to a level that can be sustained using alternative energy such as solar power. Net Zero homes look to be about 80% more efficient than a traditionally built home. To get there takes a total home approach – looking at every aspect of the build, inside and out.

 

Generally these homes are going to have solar panels as the main source of electrical supply. The next largest area of concentration is what is called the building envelope. This includes doors, windows, roof, and the walls. Properly and even over insulating the walls and making sure air does not leak out cracks and gaps is a key component. The goal is to maximize the energy usage of the home and not have any of it wasted by leaving the home.

 

The next largest area of energy usage is the HVAC and appliances. When a high efficiency HVAC system is used in parallel with a well insulated building envelope, it will greatly decrease how long it will need to run. Some homes will also incorporate a GeoThermal system that uses the ground temperature to regulate the home’s temperature. Net Zero homes are going to use energy efficient appliances throughout the home – washer, dryer, fridge, cooktop, etc. These will also be almost exclusively electric so as not to have to depend on gas.

 

The ventilation system of these homes is a very important element. With a sealed building envelope (also referred to as a tight house), the natural exchange of indoor and outdoor air is by nature greatly reduced or non-existent. This means that a mechanical solution needs to be added. Most homes are going to utilize either a HRV (heat recovery ventilator) or an ERV (energy recovery ventilator) depending on what part of the country you live in. The function of these units it to exchange the stale indoor air with fresh outdoor air with as minimum of an impact as possible on the temperature of the indoor air.

 

Other features of a Net Zero home are items such as LED lighting, low flow water fixtures, smart – programmable thermostat and even things like shingles that reduce the amount of heat absorbed through the roof.

 

Many would be asking right now why all homes are not being built as Net Zero homes. The answer comes down to cost. A Net Zero home is going to cost 10% to 15% higher than if you build the same home without all the focus on energy efficiency. If you are planning to say in the home for a long time, the energy savings will be more than the initial cost, but that can take between 10 to 20 years depending on where you live, size of the home and many other factors.

 

For more information regarding ventilation solutions, visit ww.airkinglimited.com. To learn more about Net Zero building and to see a project in process visit SYMBI Duplex One.

Sound Perception

We are constantly surrounded by sound. It is all around us. We also have ways to measure sounds. Some people might be familiar with the term Sones. In a previous post we went into depth on sones (What in the world is a Sone – how loud is my exhaust fan?). More people are probably familiar with the term decibel but might not know what it really is. The book definition of a decibel is a unit used to measure the intensity of a sound or the power level of an electrical signal by comparing it with a given level on a logarithmic scale. With these sound measurements we can get an idea of how loud or quiet a product will be. For instance, it would be logical to think that a fan that is 3 sones will be significantly louder that one that is 1 sone. Generally that would be true, but there are more factors involved. We are going to take a look at a couple main ones.

What environment is the fan installed?

Most exhaust fans are going to be placed in bathrooms. Generally bathrooms are going to have a large amount of area tiled or have hard surfaces. There is very little noise absorption in a bathroom. This is going to cause the fan to sound louder than if it was installed into say a living room that has wall-to-wall carpet with fabric couches and chairs. A great way to demonstrate this is to play music through your cell phone holding it at arms length. Now take an empty plastic bucket and put your phone inside it. Did you notice any difference in sound? The volume did not change, but the perception of sound did. Now do the same thing but this time put a towel inside the bucket first – any difference?

 

Ambient Sounds

We perceive noise differently depending on the amount of ambient sound around us. When an exhaust fan is installed into a bathroom that is isolated from the rest of the home, any sounds inside the room are going to be heard more easily. Here is another comparison for you. When you are walking on a busy city street, the sounds of cars running, even honking sort-of blends in. Now think about walking on a back road and the sound of the same car is going to be perceived as louder – especially if it honks it’s horn.

 

So what do we do with all this?

Having this knowledge will hopefully help when it comes to purchasing your next exhaust fan. Take into consideration how your bathroom is laid out, what materials are being used, is there anything in the room to absorb sound, etc. If your bathroom is going to be floor to ceiling tile, with a glass enclosed shower, the perceived sound is going to be more than if that same fan is installed into a bathroom with tile only in the shower area, large bath mats and a cloth curtain. To get the same perceived sound level, you will need to chose a fan that is considerably quieter.

 

The good news is that quiet – actually almost silent exhaust fans are readily available and Air King has the solution waiting for you. To learn about available quiet exhaust fans visit www.airkinglimited.com.

Indoor Air Quality When Staying at Home

We are living in a very unique time in history. Now more than ever, indoor air quality (IAQ) along with fresh air has become a topic of much discussion. We have dedicated many blog posts to the importance of a properly ventilated home. In light of our current time we thought it would be good to re-visit these and highlight some benefits.

Before we get started we want to make one thing clear. Exhaust fans or fresh air do not kill viruses. Even a filter is not going to kill a virus. The information we are providing is to help you evaluate and think about the air you are breathing.

In times when we are being asked to shelter in place and not leave our homes, it can have some unintended side effects. One of them being our indoor air quality. When living indoors during a time of a pandemic there are some air quality issues to think about.

First is the overall quality of the air we are breathing. With many people working from home, staying home, and so forth, it is producing more pollutants inside the home. It is just simple math. The more you are in your home breathing, cooking, working – the more pollutants’ you will generate. If you do not have a plan to mitigate those pollutants there could be longer-term negative effects. A great way to mitigate is using natural as well as mechanical ventilation.

Natural ventilation is simply opening a window and letting fresh air come in. This will dilute the pollutants in the air and if you have a cross breeze will take the stale air out. Mechanical ventilation are items such as exhaust fans and especially range hoods. Sometimes opening a window is not an option, so making sure your range hood is running while cooking or your exhaust fan is running while in the bathroom is of utmost importance.

Second is dealing with spreading a virus. Historically, proper ventilation has been an effective way to lessen the impact of a virus. A 2019 study on tuberculosis showed a significant reduction in transmission just from making changes to the ventilation in hospitals. You can read the study here. The CDC and many state departments are also recommending opening windows and bringing in fresh air to reduce the spread. Stephen Morse, an infectious disease researcher and professor of epidemiology at Columbia University’s Mailman School of Public Health says: “Changing the room air is a widely used measure for infection prevention and control. It replaces any virus-contaminated air with clean air. Opening windows is one of the easiest and cheapest ways to encourage this type of air turnover.”

Great, everyone open your windows and there is nothing to worry about – right. We really wish it was that easy, but as you probably guessed it is not. As we stated before, fresh air will not kill the virus. What is does is dilutes it to a point where it is not as contagious. There are ongoing studies to try and figure out at what point that is.

According to Erik Peper, a professor in the College of Health and Social Sciences at San Francisco State University. “People keep their windows closed to conserve heat and reduce heating-bill costs, but the lack of fresh-air circulation increases the viral density…. By increasing the fresh outside air circulation, you dilute the virus concentration that maybe shed by an infected asymptomatic or sick person,” Peper explains.

Again, fresh air and ventilation are unfortunately not the magic pill we are searching for and they need to be used properly. Here are a few considerations.

1.     If you do have someone in the house that either has a virus or thinks they might, give consideration of how the air is moving. For instance, if you have a fan in the room they are quarantined in, make sure it is pointing outside and not into the living area. Pushing the air towards the rest of the home could have the exact opposite effect and spread the virus, especially if you do not have enough fresh air coming into the home to dilute it.

2.    Understand where the fresh air is coming from. The outdoor air might be worse than the indoor air so using some type of air filter or air purifier will help. This is especially true in large city settings.

3.    There is also a concern about bringing virus-contaminated air into the home. Professor Morse says the risks of this sort of home invasion are probably minimal — with a few exceptions. “I think the possibility would be vanishingly small of a virus coming in through a window situated well above the ground,” he says. But if you have a ground-floor or basement window that looks out onto a sidewalk or some other pedestrian-trafficked area, it may be possible — albeit unlikely — for a virus to enter your home via a sick passerby, he adds.

While no one wants to be in the situation we are in, it does give us an opportunity to evaluate and learn. When it comes to our indoor air quality, there are items we can do right now as well as things we can do moving forward. What is your IAQ plan? What changes can you make now and in the future to improve?

To learn more about indoor air quality, ventilation options, and fresh air intake visit www.airkinglimited.com

Sources:

https://elemental.medium.com/the-germ-cleaning-power-of-an-open-window-a0ea832934ce

cdc.gov

https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-019-3717-9

https://wwwnc.cdc.gov/eid/article/26/7/20-0764_article

Is the Code Enough? Part 3

Over the past few blog posts we have been looking at code compliance and the difference between meeting the code and exceeding the code. In this post we are going to look at the ASHRAE 62.2 ventilation standard. In past blog posts we have described aspects of the standard such as local ventilation and continuous ventilation. In short ASHRAE 62.2 is a national ventilation code to promote air exchanges in your home to better the indoor air quality (IAQ). The basics of the code are to have an exhaust fan running continuously at a low speed, then using other fans throughout the house to take care of higher ventilation needs like cooking or when the shower is in use. Meeting the code means that you have an exhaust fan installed in a centrally located area of your home.

Great, that sounds fairly easy and for the most part it is. A popular way to solve for this is to install a two-speed exhaust fan in the bathroom. This is a fan that runs constantly on low speed at an almost silent sound level then when more ventilation is needed boosts to high speed. This can be done by a switch, humidity sensor, or motion sensor that is integrated into the fan.

So far so good; I think we have it covered. Code met, let’s move on to the next item. Here’s the thing (okay, you didn’t really think we would end it there did you?), while to the letter of the code, this installation might meet it, we need to look at it a little closer. First we need to think a little about how air travels and where contaminates are located in the home. Generally, the kitchen cooking area is going to be the location of the largest amount of contaminants generated in the home. If you are installing the continuous running exhaust fan in a bathroom, it is generally going to be on the other side of the home as the kitchen. This means that the exhaust is going to be pulling air from the kitchen throughout the home and through the living spaces. Not exactly an ideal solution. Here is another issue. What happens when the bathroom door is closed? Now you have either cut off or severely restricted the airflow. Let’s take it one step further. If the fan is installed in a master bathroom, that typically means two closed doors to navigate through.

Some installers will place the fan in the living room or a hallway. This is better as you won’t have to deal with the closed-door issue as much, but you are still drawing air that you want to exhaust through living areas. So I guess we are doomed. Can’t install it in the bathroom, can’t install it in a living area, where then?

There is a solution that takes all these issues into account. Place the continuous ventilation in the kitchen. There are reasons the kitchen is called the heart of the home. Typically the kitchen will be in a central location of the home or at least open to the rest of the home. This makes it a perfect location. There are now range hoods available that have multiple speeds. They have a continuous operation speed that will solve for, as the name states – continuous airflow. The sound level at this speed is barely detectable. When the cooktop is being used, they have higher speeds to take care of the additional airflow needed to properly ventilate while cooking. Now you have the ventilation placed at the source of one of the largest contaminators of the home. The added benefit is that the continuous speed will take care of the residual contaminants in the air after the cooking is done. While we would like to think everyone is properly using their range hood, we also know that is not always the case. These range hoods install the same as traditional range hoods, so if you are installing one anyway, why not solve two things at once. The only consideration is that they are going to cost more than an entry-level basic range hood. The counter to that is if you go the bathroom route, a two-speed exhaust fan is also going to cost more than a standard exhaust fan also. Another point is that you will also have a much quieter operating range hood.

When it comes to solving for ASHRAE 62.2 continuous ventilation, there are options. Some designed to meet the code, some designed to exceed the code. Hopefully this gives you some things to consider. For more information about continuous operation range hoods or ASHRAE 62.2 solutions visit www.airkinglimited.com