It used to be that the most important rules to know about ducting were "Don’t stand on it," and "Don’t use duct tape to repair it after you do." With an increased awareness of all things efficiency-related, though, things have changed. Here in the Tulsa metro area, with a documented high of 115 degrees and a record low of minus 12 in 2011, efficient HVAC is a big deal. If you’re considering a ductwork redo or replacement, there are several factors to balance when deciding: flex metal, or rigid?Inherent ProblemsFlex duct is unarguably easier to damage, and over the years our lofts and crawl spaces see several visitors -- the cable guy, the electrician, the plumber -- to whom HVAC installations aren’t a priority.The flex duct itself, though, isn’t to blame when it’s stamped on or kicked. That said, it does have some inherent problems that are addressed by a rigid installation:• Flex fails most often where it kinks or makes sharp turns.• Long, poorly supported runs of flex duct sag, stress and separate.Rigid ducting systems, often called hard pipe, are prone to their own brand of installer pitfalls, particularly extra duct length:• If cutting-off is awkward, or just too time-consuming, unnecessary dead-end extents are sometimes capped off and left. They are vampires, silently sucking away at your energy budget.• Connections that are poorly fastened and sealed are sometimes not as easy to visually identify in a rigid installation, so can remain unattended-to for longer.Food for ThoughtHere are some factors to take into consideration when debating between a ductwork redo or replacement, particularly when choosing between flex metal and rigid (the pros and cons of are, of course, reversible):• Flex is practically impossible to clean.• Flex is less efficient at retaining the temperature changes effected on treated air.• Rigid is more time-consuming to install.• Rigid is more expensive -- often quite conspicuously so -- at initial purchase.Air Assurance maintains a staff of over 60 technicians, all fully conversant with ductwork issues. Contact us to arrange a free in-home consultation.Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems).
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