How to size an HVAC unit?

[mdevera211]

While waiting for a dream job, I'm doing service work on my own and I notice homes that are only 5 years old have undersized units? Can anyone tell me what size an HVAC unit should be or how to size a unit for homes? I had a service call for a condensing unit not running and I noticed it was an obviously undersized unit for the home. It was a 3100sf home with a 3 ton or 3 1/2 ton condensing unit. Could anyone tell me what size unit that home should have? I'm thinking it should at least have twice what it currently have. The customer said it takes a long time to cool the entire house.

[the dangling wrangler]

Here's one way.


http://hvaccomputer.com/talkref.asp

[beenthere]

Guess that means you think a 4000 sq ft home should have more then 2 tons of A/C.

Sq ft alone. Does not indicate what size A/C a house needs.
Use the posted link. And you will be able to learn how to size.

Next. An under sized duct system. Will make a properly, and an over sized A/C take long to cool the house. A/C is not suppose to be a quick process. Since in most areas. Dehumidification is an important part of the cooling process.

[jdavis72]

And you're a service tech?

[trey r]

While waiting for a dream job, I'm doing service work on my own and I notice homes that are only 5 years old have undersized units? Can anyone tell me what size an HVAC unit should be or how to size a unit for homes? I had a service call for a condensing unit not running and I noticed it was an obviously undersized unit for the home. It was a 3100sf home with a 3 ton or 3 1/2 ton condensing unit. Could anyone tell me what size unit that home should have? I'm thinking it should at least have twice what it currently have. The customer said it takes a long time to cool the entire house.

Was it a 3 ton or 3 1/2 ton? Since you obviously don't know how to size equipment how are you determining it's undersized?

[the dangling wrangler]

Hey BT, why not tell this guy about applying for professional status.
He's got the post count. Seems like he's trying to learn something.

[beenthere]

Hey BT, why not tell this guy about applying for professional status.
He's got the post count. Seems like he's trying to learn something.

What. You couldn't copy and paste from one of my post with it in.



OP:

You have the post count, apply for Pro Membership.
Use this link and Apply for Pro Membership

Once accepted, you have access to the pro tech forums. Where you can ask and get answers to technical questions.

Plus, you also have access to the Pro Educational Forums.

All of it is free.

[the dangling wrangler]

What. You couldn't copy and paste from one of my post with it in.



OP:

You have the post count, apply for Pro Membership.
Use this link and Apply for Pro Membership

Once accepted, you have access to the pro tech forums. Where you can ask and get answers to technical questions.

Plus, you also have access to the Pro Educational Forums.

All of it is free.

That's the ticket!
I'll bet you agree. No need to give the guy a hard time. Let's try and help him.

[beenthere]

We all jump the gun once in a while.

Stress relief.

[the dangling wrangler]

We all jump the gun once in a while.

Stress relief.

Honestly, I've never seen you be mean to anybody. And, there's some you should have.

[beenthere]

I slip once in a while.

Try not to though.

[absoair]

It's tough being nice in a mean world. You have done a good job today.

I'm sure they wouldn't let just anyone be a Moderator.

[the dangling wrangler]

I'm sure they wouldn't let just anyone be a Moderator.

They will for money!

http://hvac-talk.com/vbb/showthread.php?t=399892

[beenthere]

ROFL.

It serves 2 good things.

1. The charity that receives the money.
2. Someone (the winner) gets to see all sorts of new tabs on his/her screen. And hope they don't click the wrong one.

Who ever wins, will have plenty of help. And Admin can undo almost anything we do.
Its more of a democaracy then people might thing.


Robo won the first mod contest however many years ago it was.

[absoair]

Oh yeah, I forgot about that auction thing.


I wonder how much authority they will actually allow?

[the dangling wrangler]

ROFL.




Robo won the first mod contest however many years ago it was.

I think I was here then.
I don't remember him banning anybody either.

[beenthere]

We vote on a lot of things/actions.
We don't ban someone just because we don't like their opinion.

As far as I know. The winner will have full mod access.

[the dangling wrangler]

I wonder how much authority they will actually allow?

I don't imagine a whole lot. It's only for a few hours in reality.

[secorp]

A couple of good ways to size a home......

One is two purchase the three card board cutouts from Don, then go to the curb in front of the house and hold them up until the house fits into one of the three cards labeled 3, 4, and 5 tons.


The other time tested method is to go across the street, between 30 and 40 feet, hold up three fingers, then four. then your hole hand if need be. the point is if three fingers cover up the front door it is a three ton and so on.

[the dangling wrangler]

A couple of good ways to size a home......

One is two purchase the three card board cutouts from Don, then go to the curb in front of the house and hold them up until the house fits into one of the three cards labeled 3, 4, and 5 tons.


The other time tested method is to go across the street, between 30 and 40 feet, hold up three fingers, then four. then your hole hand if need be. the point is if three fingers cover up the front door it is a three ton and so on.

That way is too time consuming.
All ya gotta do, is count the number of exterior doors on the home.