ACCA Manual J

[scott14]

Is there a place I can review a copy of what exactly a Manual J & D encompasses? For example, I believe that I am being misled by several contractors as to what size equipment I actually need. It is my belief that they are simply manipulating variables to achieve the results they wish in order to obtain my work. I believe this because some of the contractors have much different system requirements than others. Is this possible?

[Lorne]

Maybe at the library. Manual J covers the actual figuring of the load on the home. Giving R values to diferent types of material and how to add it all up. Manual D teaches how to do duct design. If the company does not have much experience in Hvac figures can be way off. I would suggest that you have each company give referals to jobs they have done load calculations on or just other referals and then decide. Not many companies a have done load calculation for very long and are getting back to it. Also ask for a print out of all data input to figure load. Then do your own with the Hvac load program promoted on this site. Don't however rely on yours to be the right one. Just a basis to make an informed decision.

[jjohnson]

Hi - As a homeowner in need of a new HVAC system I needed to learn about heat loss and gain and Manual J in a hurry. I downloaded HVAC-Calc from http://www.hvaccomputer.com which is a program to calculate the manual J heat loss. It did the job just great for me, comes with a very informative manual and costs only $39 for homeowners. I recommend it!