HVAC Systems



             


Wednesday, November 28, 2007

Updating Your HVAC System

The shock of skyrocketing utilities bills may have you thinking about upgrading your HVAC system?. and rightly so, because there is no chance the fuel costs are going to go down.

The newer heating and air conditioner systems are much more efficient than older units and offer significant long-term energy savings. The Government has mandated that any cooling units should have a SEER rating of at least 13 starting in 2006 and this is good, because a twenty-year unit may have a SEER rating of only 7 or 8. However, for real savings you should look at your whole home as an energy eating beast that needs to be put on a diet. This includes repairing air leaking windows and door seals

It does little good to replace an older HVAC system and expect great reduction in utility bills, if you don?t attend to the areas where you are losing energy. New HVAC systems are expensive and the temptation may be to just install a new high efficiency furnace and air-conditioning system and hope for the best. The fact is, the reduction in utility bills may be disappointing because you may have overlooked a major player in the whole HVAC system?. like the ductwork.

A poorly designed, leaking and under insulated ductwork system can waste 30 percent or more of the money you pay to run your heating and cooling system.and nullify any gain you might realize by installing a new high efficiency system. Many duct systems are poorly insulated and leak conditioned air into un-conditioned attics and crawl spaces. I commonly find disconnected ductwork during my home inspections.

When ducts leak, conditioned air can be forced out unsealed joints and lost. In addition, also un-conditioned air can also be drawn into return ducts through unsealed joints. Attic temperature can be very high in the summer and cold in the winter?so, any attic air that enters your system through un-sealed duct joints will have to be cooled in the summer and heated in the winter, this increases the load on your system and increases your energy bill.

Surprisingly an older home may have a much better designed duct system than a new home and may only need a leak check and insulation upgrade. Newer homes on the other hand may be victim of cost cutting measures and poorly designed duct systems. The use of flex duct has grown in popularity because ease of installation and the high cost of shop made sheet metal ducts. Flex ducts even installed properly are a poor substitute for well designed properly insulated sheet metal ducts. It is common practice to make plenums and coil boxes out of taped together duct board.

Be sure to include an evaluation of your ductwork system in your plans to upgrade your HVAC system. There is no use in exhausting valuable conditioned air to the great outdoors through leaks and worn-out duct insulation. If your duct system needs an overhaul, you might want to consider a high velocity delivery system that uses smaller PVC pipe ducts. These high velocity systems are much easier to install and insulate. The bottom line on a HVAC system upgrade for maximum efficiency must include more than just the new equipment. Don?t forget about the duct work and include it into your budget.

Jim McDonald is a retired contractor and a licensed home inspector

jim@getinfoweb.com

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