Ventilation

Commercial Ventilation

Ventilation is one of the most important tools you can use when you are purifying the air in an inside space. Overall the best method of cleaning air is to remove the polluted air and replace it with clean air from outside or another clean air source. This page is about ventilation concepts. We will provide you with important insights and links to LakeAir products that can help with your ventilation needs.

When to use Ventilation

Many municipalities require ventilation in commercial buildings. This is most common when the establishment contains a commercial kitchen. The second most common reason for required is when smoking inside is a regular activity. The amount of ventilation required is different in many situations.

Capacity Based Requirements

Many smoking establishments have the amount of ventilation required based on the capacity of the are in question. ASHRAE, one of the leading authorities on heating, ventilation and air conditioning recommends up to 20 CFM (cubic feet per minute) for each person in any given commercial space. However the numbers you are likely to be presented with are 70 CFM per occupant. This number comes from the international Mechanical Code. So, if your establishment has an occupation capacity of 100, you may be asked to provide between 2000 and 7000 CFM of ventilation.

Use Based Requirements

While use based requirements for ventilation are not as prevalent as occupancy based numbers, they are still helpful. In some municipalities there are local codes that require a specific number of air changes per hour in a space, based on the use of that space. We have seen requirements as high as 25 air changes per hour for a smoking venue. This requirement was for a space where cigar smoking was a regular activity.

Reasons to not use Ventilation Alone.

There are several reasons why you might not want to use ventilation alone as the sole way to clean the air in a given space:

Ventilation Costs

Installing ventilation can be a very expensive proposition. Air handling units can cost 1000’s of dollars. The installation of associated ductwork and vent covers can at times be more than the air handling unit itself. The cost of re-heating or re-cooling the fresh air from outside is sometimes the most expensive part of this ventilation equation.

Outdoor Air Quality

As the air in our world becomes more polluted the option of replenishing indoor air from outside is dwindling. Between wild fire smoke, smog and other air pollution sources, it may not be reasonable to use outside air ventilation to clean the air in an indoor space.

Access to Outside Air

We have come across many customers who cannot access outdoor air. Some cases are businesses in high rise buildings. The other are historic buildings that do not allow penetrations to the outside. If you can’t get to the clean air, you can’t use it to ventilate a space.

ASHRAE & the IMC on Difficult Ventilation Situations

While ASHRAE and the authors of the International Mechanics Code might like to see every air quality situation solved with ventilation, they are realists and have made exceptions to these recommendations. In ASHRAE’s standard 62.1(2012b) they “allow that filtration and air cleaning, together with recirculation, can be used as a substitute for a portion of outdoor air ventilation. This is conditional upon detailed analysis of contaminant sources, rates of contaminant removal by air-cleaning systems.” In most cases bringing this information to the attention of a municipalities’ inspectors is enough to get an allowance.

If the quote from ASHRAE does persuade your inspector, point them to International mechanical code 2021. In chapter 4 on ventilation, the code spells out that the use of recirculated air that is filter shall NOT be prohibited. The very code they quote, allows you to use proper filtration. This hidden gem is found in the note “b”, in the line for smoking lounges. Here is a full explanation of note “b” :

Note b in Table 403.3.1.1 of the International Mechanical Code (IMC) specifically addresses ventilation requirements for smoking lounges. It states:

“Mechanical exhaust required and the recirculation of air from such spaces is prohibited. Recirculation of air that is contained completely within such spaces shall not be prohibited (see Section 403.2.1, Item 3).

This means that:

Mechanical Exhaust: Smoking lounges must have a mechanical exhaust system to remove air from the space. This system should be designed to effectively remove smoke and other pollutants generated by smoking.
No Recirculation to Other Spaces: Air from smoking lounges cannot be recirculated back into other parts of the building. This prevents the spread of smoke and other pollutants to non-smoking areas.
Recirculation Within the Lounge: Recirculation of air within the smoking lounge itself is generally allowed, as long as it is properly filtered to remove contaminants. However, this should be done in accordance with Section 403.2.1, Item 3 of the IMC.

The goal of these requirements is to protect the health and safety of building occupants by preventing the spread of smoke and other harmful pollutants from smoking lounges to other areas of the building.

Important Requirements

Make-Up air and ventilation in general may be governed by different local laws and codes. It is best to always to check what rules may apply to your business location. Two common rules that you should always take into consideration.

1: Keep Intake and Exhaust vents at least 10 feet apart. It makes no sense to bring fresh air into a space to immediately exhaust it back outside.

2: Make-up Air should not be larger than the existing HVAC system can handle. Your heating and cooling system will provide reliable service for set amount of area. You should not add make-up air that is more, when added to the spaces needs system can handle.

If you need help understanding how these codes, rules and regulations my effect your project, please call our CEO Randy Bush (262) 632-1229.

LakeAir Ventilation Products

LAC MUA-900

900 CFM Make-Up Air Unit
Duct Adapters 12 / 10 / 8 inch
On Board WIFI / WIFI @ Switch
150 – 900 CFM
Galvanized / Black / White
$1450.00 – $1650.00

Power Vent 24 x 24

1000 CFM Power Vent
Duct Adapters 12 / 10 / 8 inch
Variable Speed
WIFI or Switch Controlled
$850.00 – $900.00