Building America homes etc.
Are there really true stories of the Houston Area "Building America" homes not cooling OK? I am very interested in what I can learn from this.
Is it because the actual heat gain is higher than calculated? Is the AC system not delivering enough cooling BTUs? Latent BTUs? Sloppy work by Pulte?
If anyone can provide facts to answer any of those questions, that would be extremely interesting and educational. Since I live near Houston, very relevant too. To me this amounts to a revival of the old question whether Manual J is the right tool in this hot-humid climate. Most of the people who say it isn't don't seem to have enough vocabulary, or math background to explain why. Answers from this angle might supply the missing argument.
Thanks in advance -- P.Student
Re: Building America homes etc.
So my guess with a statement like that you believe everything you read, So do you believe everything you read? or is it possible that some of us think outside the box of things figured in a classroom or lab and have been to a live home and seen how these numbers perform in a real world? The only perfect writings are the inspired word of God that I trust 100%. I can't say as to how these numbers perform in the real world like Al "classical" can he has been to one, but you can bet you last dollar that I will visit one of these homes soon and I will post an exact statement here from the HO, I think that would be fair.
Originally posted by perpetual_student
Most of the people who say it isn't don't seem to have enough vocabulary, or math background to explain why. Answers from this angle might supply the missing argument.
Re: This is getting personal
There is no problem with manual J. If everything is exactly like the values you use to determine the load which is easier to do in a new home and harder to do in a existing home. It leaves little room for error if a mistake is made or a guess at insulation in the walls are wrong. My biggest problem is homeowners not knowing in advance what the system will do in the extreme temps. All of my customers would rather pay a little more in the milder months for being a little oversized than have to add a window unit or set and watch tv with a blanket over them. It is easy for someone to say manual J works every time but are they the ones that have to answer the phone on the days it gets above or below design temps and explain why the new system they installed won't keep up? How many furnaces and A/C units have YOU installed Uktra?
Originally posted by perpetual_student
>>So my guess with a statement like that you believe everything you read,
>>So do you believe everything you read? or is it possible that some of us
>>think outside the box of things figured in a classroom or lab and have been
>>to a live home and seen how these numbers perform in a real world?
MrBill, I would much prefer you show me wrong and explain WHY or HOW these homes fail to perform. Yeah I was baiting the Manual J doubters just a bit but you have not lessened my doubts at this point. I do respect that you have much real world experience, I do notice that you are skeptical of Manual J but don't necessarily believe in those things written by you or some others. If only I could hear a plausible theory of WHY or HOW Manual J fails to deliver satisfactory comfort, then I could come around and be much more sympathetic to your views.
I am not saying that you are wrong, however I am waiting for something more persuasive than "I seen it" testimonials. Because if you haven't noticed, there are a lot of people who say "I seen it" in favor of Manual J working.
Myself I have received quotes from AC guys who claim my 2 systems are undersized at 7.0 tons. One guy wanted to up me to 9.0 tons, of course that would require all new ductwork and the price of a pretty good car. Yet my house cools OK, one system is measured at 73% duty cycle and the other at 93% (as measured by minutes on vs. off in the peak hour). Is that not serious evidence I don't need 9.0 tons? Just who is thinking inside a box here?
Regards -- P.Student
[Edited by trane on 06-30-2005 at 11:04 PM]