Duct Leakage and Duct Performance, What's the Difference?

Well this is a question that we are getting a little more frequently  but we should hear this question way more often.  You remember the old adage of statistics or analysis or the business accountant. 'If you focus on something, it improves.'
This is the topic.
ENERGY and COMFORT.
As Gulf Power prepares to add to all of our power bills' we should focus on offsetting that increase with a little knowledge and ask a couple questions.
1) Does my HVAC & duct system perform like it should ?
2) Do I have duct leakage? What is that costing me every month or every year?
Lets start with a couple basic ideas
Duct Performance:  If you have a 3 ton A/C system are your getting 3 tons of cooling (tons, in this case is not weight, just a silly science definition of cooling capacity) the tonnage in a duct system relates to airflow and air flow to performance.
Lets simplify: 1 ton of cooling equals 400 cfm of air flow thru the duct system, 1 cfm (cubic foot per minute) is equal to about as much air in a basketball.
So when a 3 ton system runs we are looking for 400 basketballs of air per ton or 1200 cfm total coming out of the duct.
We measure the airflow at every vent,  add it all up and...presto...Duct performance!
Did we get 1200?  If not we have a problem... maybe multiple problems!  Like... leaks, restrictions, blockage or undersized duct maybe even oversized A/C equip (this is common because "bigger is not better" when we're talkin' Air Conditioning )

Duct Leakage: We put the duct system under negative pressure with NO air flow and measure what's leaking out.  This is the most common issue we see when we measure find out why duct performance is not up to snuff.   Duct leakage is the missing basketballs' of air that you should have in the room  but they are not, instead, they are leaking into the attic or crawl space.  We often find that there are plenty of basketballs of air in one room (a small office or bedroom, lets say, and not enough in a large room like the Kitchen, Dining room or Living room)

So lets conclude this lesson by saying this again "if you focus on it... it usually improves"
know your duct performance & Duct leakage numbers and you will easily find a place to offset the upcoming Gulf Power Rate Increase.

For a short video about the tests ( Duct Performance & Duct Leakage) go to our website for a quick look at the consumer Education Videos  http://www.gulfcoastaircare.com/