Ventilation Design Basics

HVAC systems provide heating, ventilation, and Air Conditioning to buildings. Whether it is an office building with 300,000 square feet or a Japanese Steak House, the principals are all the same.

I have placed a diagram to the right which may help give you a better idea of the system layout. Air flows into ductwork from the building through ceiling registers and mixes with air pulled in from the outside at the air filter section. Next you have a blower which moves the air across two sets coils, one to cool, for the summer, and one to heat, for the winter. From there the air goes back into the building through ceiling diffusers.

The way you heat and cool the air is where a lot of people begin to get lost. But, this is typically because the person explaining is too scared to actually help and if they teach you, they are afraid you will not need them. What that does is create an cloak of magic that seems to engulf Ventilation system design. Whether trying to remove grease, smoke, heat, dust or airborne bacteria from an air stream the guiding principles are all similar. One of my goals here is to help remove the mystery and help educate, any feed back that can be given on these articles would be greatly appreciated.

One of the key elements you must remember when designing a well balanced air system is that you are designing for people in the real world and not in a laboratory. Engineers are great at coming up with ideas which work in theory, but then it leaves the customer scratching his head trying to understand why their restaurant is filled with smoke, the kitchen floor is greasy, and why his customers can not open the door to come in and eat. Same idea with office buildings, you can have trouble opening doors, residual moisture on windows, people constantly sick, and no one is comfortable. All because one person over looked the human element.

I do not want to overwhelm anyone so we will end this lesson here. Next we will look at how equipment conditions. Thanks for reading, and we'll see ya on the roof!