Quote:
Originally Posted by TXRunner
...but I'm lured by the temptation of high SEER ratings. With this company... I love polls.
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In this case- forget the poll!
And the lure may just be a way for the contractor to get more money out of you.
SEER ratings are done by independent laboratories- under the very best of conditions- which is not the average house across the country. So, real field conditions come into play; or "field adjustments". In some cases for example, a house could have a SEER 17 unit but, it's operating at a SEER 9 capacity- where's the "savings" in that?
Generally speaking, a lot of HVAC contractors still don't use, refuse to use, have no earthly idea how to use a Manual J for calculating the size of an A/C system(s) for a house. You say you have 9 tons of cooling right now- old calculation says you have 4500+ sq/ft of house, correct? If that not correct- well, that just proves my point.
With today's ever increasing fuel costs it makes sense to calculate to the very best known abilities. Meaning not only is a Manual J calculation needed but, a Manual D calculation also- especially when upgrading/replacing current systems. If the current contractor you're working with hasn't done a J and D calc, have them do them, or move down the list to the next contractor that will.
Of course; that's just the beginning, along with the properly sized system(s) there is determining if you have the correct amount of insulation in the home. How well is the home sealed? Are the windows a thermal type? Do they have low-E coating? Is the low-E coating correct for your region? Do they have sufficient weatherstripping? Etc., etc.