wrote in message
...
I am going to put central heat and cooling into a remodeled (rebuilt
actually) home. I read up on it and have been reading here. My problem
is the first guy came and gave me a quote by just looking at the
rooms, asking me what the square footage was poking his head up into
the attic, and taking a look at the electrical box.. In Consumer
Reports, it said don't let them do that they should do some other
things in fact they say: "Contractors who bid on your job should
calculate required cooling capacity by using a recognized method like
the Air Conditioning Contractors of America's Residential Load
Calculation Manual." I am assuming that his 15 minute perusal of the
house and writing of estimate might not have included this?

He gave you a price quote, not an engineering analysis. He may be right on.

To determine exactly what you need there are some calculations that must be
done. It takes some time to do that detail work for a job he may or may not
get. If he is experienced, if he has done many jobs, he is probably able to
quote a price by using the data bank of his head. If you accept his bid, he
can (and should) do a more detailed layout for capacity, piping, ducting,
etc.

Let me give you an example. I worked for a company that had two people
doing quotes for the sales staff. Quotes involved making tooling for molded
parts. One guy would take four to six hours of estimating, calculating,
getting prices for materials. The other guy would quote off the top of his
head in less than five minutes. The guy that was taking the long time
complained to the president of the company and said he would not be
responsible for making the tools at the prices quoted by the fast guy. He
then asked both to quote four jobs. Estimator A took two days to get the
quote. Estimator B took 15 minutes. On each item, there were within $100
on tools that cost from $8000 to $12000. The $100 difference was small
change compared to the tens of thousands of dollars the tools would
eventually bring in making the molded parts and that time saved in being
more responsive to the customer.

This is not to say the contractor gave you a good or bad price, but he is
comfortable in doing the job for that rice. See what others have to say
before you disregard the first one. He may or may not do a good job at any
price.