Friday, January 25, 2008

Duct, duct, goose!

I'm glad I'm not Mrs. Cheapo, because my husband is insisting on metal ductwork for the house which is the most expensive way to go for your HVAC (Heating Ventilation Air Conditioning) ductwork. My husband, the typical Swede, is so quality driven that he absolutely insists upon it.

From what I've learned, there are a few good reasons. We talked to several geothermal, HVAC consultants and took a couple of classes where they have said the same thing - Metal ducts are better. Metal ductwork lasts longer, is easier to clean, doesn't get particle buildup as easily as flex duct and the air flows better (less possibility for restricted airflow, which causes A/C inefficiency!). A/C usage and inefficiency accounts for a lot of Texan's house bills, so this is pretty darn important. You must insulate the metal ducts on the exterior to keep it from sweating if it's cool air or losing its temperature if it's heat. The only disadvantage I can see besides the expense, is that there have been cases where sound travels through the metal ducts to other parts of the house. There are solutions to fix this (duct liners), but I don't know what that does to the efficiency of the ducts (which will defeat the purpose of the metal ducts!).

The alternative has been to get flexduct (the most common in new homes) or fiberglass ducts (made with a rigid fiberglass duct board). The advantage is that it's way cheaper and already insulated. The problem that occurs is that flexduct bends, restricting airflow and being a lot more inefficient. They can also bust open (some guy found a little rat's family home in one once!EWWWWWW) if little critters can get in, and they are difficult to clean.

Also, you will want to clean your ducts periodically, as there is always a danger of getting fiberglass particles, mold or dust in the ductwork. You do NOT want to breath fiberglass, as that is super dangerous to your lungs, which is why you always need a mask when putting in batt (fiberglass) insulation. With metal ducts, it is easier to clean very thoroughly with a brush. Another tip is that if you are sealing your ducts, always use MASTIC tape not DUCT tape, as mastic tape is better quality and does not wear out as easily as duct tape.

Metal ductwork will cost us about $4,000-5,000 more than using flexduct or fiberglass. But again, my husband says it's worth it! (*sigh*). I guess we're going to have to wait a little longer to get another car :-).


Kristy said...

I completely agree with your choice of ductwork...metal is the way to go. The previous owners of my house decided to do the alternate and it's horrible. #1 the flexduct has taken over my basement and looks like a giant octapus. #2 They didn't even do it right and I have these huge bowing areas where nothing is supported. Plus, when they connected it to the metal registers, they used ducttape and when it started to come off, they just put more over it.

My house would probably be warmer now if these problems weren't here; but what are you gonna do.

This is definately one of the things on my To-Do List. Let us know how it goes.

theartofengineering said...

I agree. Do it right use metal. I'm an HVAC engineer and it's the only way I'd go.

haynesj1 said...

Did you consider the Daikin systems when you were researching HVAC?