# J loads



## Tim`s Plumbing (Jan 17, 2012)

I was wondering if any of you guys know how to figure J loads manually ? I am quoting a job and the town the job is in requires a J load be done before any permits wil be giving. I can have one of my supply houses do it for me but I am in a bit of a rush.


----------



## MarkToo (Dec 17, 2011)

What the heck is a "J" load?


----------



## trick1 (Sep 18, 2008)

MarkToo said:


> What the heck is a "J" load?


He means manual j.

Its the manual way to perform heat loss calculations for buildings.

I have the newest version of manual j but I use a heat loss program from slant fin.

It works well and is based on manual j. It was free if I recall.

You can check on the slant fin website. It still might be there.


----------



## drtyhands (Aug 16, 2008)

Google took 1.5 minutes to inform me that you should have a software program to calc heat and air.Manually is too laborious to get all the numbers in.I had to listen to a loudmouth contractor brag a few weeks ago how he has a designer employed in his company...My buddy owns a Heating and air Co.."Big deal,we all do our own calcs"

Just like us drawing our own for ground up plan check.


----------



## Tim`s Plumbing (Jan 17, 2012)

I think I will wait for my supply house to do it for me.


----------



## OldSchool (Jan 30, 2010)

Here is a formula you can use

Sent from my portable office....yes I am at work


----------



## drtyhands (Aug 16, 2008)

Tim`s Plumbing said:


> I think I will wait for my supply house to do it for me.


Might be alot easier.Are they going to charge you,I wouldn't think they will.Are you going to be starting to put in more new systems.The software sounds cheap in comparison to it's capability.

When I interjected to ask the spewing HVAC contractor "How is that any different from a Plumbing or Electrical contractor calcing out a system"
His coment was "Well we have a bunch of different variables.Like...The color of the different NSEW facing walls,the color of the roof.Our engineer is very thorough.".
This guy knew how to play to an ignorant crowd.Anyone in the trades for any measurable amount of time would have yanked this guys card.

Good luck on your job,have fun.


----------



## Tim`s Plumbing (Jan 17, 2012)

drtyhands said:


> Might be alot easier.Are they going to charge you,I wouldn't think they will.Are you going to be starting to put in more new systems.The software sounds cheap in comparison to it's capability.
> 
> When I interjected to ask the spewing HVAC contractor "How is that any different from a Plumbing or Electrical contractor calcing out a system"
> His coment was "Well we have a bunch of different variables.Like...The color of the different NSEW facing walls,the color of the roof.Our engineer is very thorough.".
> ...


 No they will not charge me as long as if I get the job I buy the combi unit from them.


----------

