Estimator didn't do a load calculation, just looked at size of existing unit

[RAJ]

He just asked me if the existing system cooled properly. Is this acceptable? How would a different sized system effect the existing ductwork though?

[roger61611]

[m Ransley]

An oversized unit wont remove as much humidity, it will run less. Is your house humid even when cool, high humidity makes even cool temps more uncomfortable.

[J. Clarke]

Yes he did. What of it?

[Edwin Pawlowski]

Maybe. How well does it perform? To hot at times, too muggy at times?

By different, do you mean smaller or larger? Are you changing just coils and condenser or changing the air handler also?

Unless you are absolutely sure it performs well as is, I'd try another dealer and get the calculation done.

[RAJ]

[Chris Hill]

If you bought a higher efficiency system, you may need larger ducts because I believe they need to push more air. That's what I've read anyway. Don't feel bad, last time I had mine replaced I called three people and none did a load calc. Next time I think I'll offer to pay for the estimate if they'll do one and show their work.

[RAJ]

[aka-SBM]

If you are getting ESTIMATES, you are getting screwed anyway. Dont allow anyone that cant QUOTE you to the penny the job. Estimate is a nice way of saying, its gonna be in this ballpark, and f*ck that.

[RAJ]

[m Ransley]

You said it is humid, so you just answered your own question. A VS unit can be set on real low and pull out the most humidity, a Vsdc unit can pull only 100-120 watts on low and be left on continously. but get the

10yr warranty.

[aka-SBM]

Of course it does. Why should he do someone elses homework for free?

[STravis]

RAJ, why do you care about seeing the actual calculations? If the end result is that you need a furnace of XXXBTU, what difference does it make how he got to that conclusion (or are you supposed to verify his work?). If you were looking for more quotes you would then use the end result to ensure that the other guys aren't off the mark, right?

[aka-SBM]

So..what you are saying, if he gets a quote for $3000, one for $2500 and one for $1000, then he should not care who actually did a load calc right? Or..he gets 3 quotes for the same price.......but three diffent sized units..he should just throw a freaking dart at the quotes right?

He needs to know who did the work, have them show him the calcs, and explain how the calc, and the quote, compare, since there are times you will end up rounding up, or down due to the final numbers.

[STravis]

Nope, that's not what I said. The suggesting was that as long as the individual goes through the process of doing the calculations then the result is what matters. At the end of the day, unless they are completely incompetent they should all come up with systems in the same area. If they don't (and claim that they performed the calculations) then some of them are lying and in this case, you wouldn't be able to tell who is lying until after you signed with them.

But according to this guy (and you agreed with the result) he doesn't get to see the calcs until after he's signed the work agreement. What good are the numbers at that point?

I

[Chris Hill]

I'd care because unless I see them I won't know if anything was actually calculated. Last time I had the job done none of the three guys I called calculated anything.

[DK]

Load Calcs are usually not necessary. Within 5 miles of me, there are 10,000 homes built by the same 3 builders, each using 5 building plans. Everyone in the hvac business knows exactly what size unit these 5 plans require.

The only load calcs necessary are the 7 custom built 7 bedroom homes that get built each year.

Do all these homes have exactly the same size units for the same plan? - No, of course not. Joe and his wife like to run their thermostat at 60 degrees year around, even in 105 degree spells. Theirs is a 5 ton system while their friends have a 3 1/2 ton system.

All it takes is a brain and talking to your neighbor., not a load calc - that will probably be inaccurate anyway.

.

[Chris Hill]

Depends on the area in which you live. In a subdivision of new construction I'd agree. The problem is that once houses get some age on them they begin to vary. For example, there is one house in my neighborhood like mine. It has the original windows in it, which are probably not very efficient. It has the original siding on it as well. Nobody has even thought to plant trees to shade it and possibly reduce the cooling load. In about ten years my house won't need near as much cooling as my neighbor's will.

[STravis]

Very good info right there. In fact all the HVAC companies that have given me estimates on my new estimate (except the one guy) all sized furnaces in the same BTU range based on square footage of the house and existing duct work. These guys know what these homes are like and what it takes to heat/cool them. Yes, they could spend 30 minutes or more doing a load calc but unless they know EXACTLY how the house is built (wall/window R rating, etc), that information may be innacurate...as the saying goes "garbage in..garbage out".

[STravis]

The above should have read "estimates on my new furnace"...