Line set for New Amana ASZC16 HP


  #1  
Old 04-27-10, 11:50 PM
E
Member
Thread Starter
Join Date: Mar 2009
Location: San Antonio, TX
Posts: 33
Upvotes: 0
Received 0 Upvotes on 0 Posts
Line set for New Amana ASZC16 HP

Replacing a 7 yr old 3 ton Trane HP with a Two-stage 4 ton Amana HP. The existing line set is 3/8OD and 7/8OD. The new unit calls for 3/8OD and 1 1/8OD for the suction line. The air handler is on the second floor with approximately 45' horizontal run and 20' vertically (up into the attic and back to the AH connections). My question is how critical is it to increase the size of that suction line?
 
  #2  
Old 04-28-10, 04:35 AM
airman.1994's Avatar
Member
Join Date: Dec 2005
Location: VA
Posts: 5,491
Upvotes: 0
Received 8 Upvotes on 8 Posts
VERY!!!!!!!!!! Why the increase in HP size????????????? Is the duct big enough to handle the higher CFM?
 
  #3  
Old 04-28-10, 10:32 AM
E
Member
Thread Starter
Join Date: Mar 2009
Location: San Antonio, TX
Posts: 33
Upvotes: 0
Received 0 Upvotes on 0 Posts
No clue regarding the duct size. House calls for a 3.5 ton (2400sf in SA), my understanding is that Amana does not make a 3.5 ton unit.

Why is it critical? Why does the line need to be larger?

The existing line is between the wood frame and the brick veneer, which seems very difficult to replace, and I don't really want an external pipe running up into the attic (unsighlty).

As a secondary option, is it possible to utilize the portion of line between the wall, and upgrade the horizontal run in the attic?
 
  #4  
Old 04-28-10, 02:43 PM
airman.1994's Avatar
Member
Join Date: Dec 2005
Location: VA
Posts: 5,491
Upvotes: 0
Received 8 Upvotes on 8 Posts
You might be ok because the unit is 2 stage but your HVAC contractor should have looked at it. If the unit calls for the larger line that is what needs to be used. The unit will work harder and be more efficient with the right line set. Piping should be placed in a duct that looks just like a down spout. Your HVAC guy should know this.
 
  #5  
Old 04-29-10, 09:25 AM
E
Member
Thread Starter
Join Date: Mar 2009
Location: San Antonio, TX
Posts: 33
Upvotes: 0
Received 0 Upvotes on 0 Posts
The contractor called Goodman and he was told it was OK to utilize the existing 7/8 suction line. I guess what I'm trying to figure out is why would the specs on the Amana website call for 1 1/8? In other words, what is the purpose or reason behind having a larger diameter pipe? And what effect will utilizing a smaller diameter pipe have on the system?

The tech told me about the down spout, I just think it looks unsightly, so I want to explore viable alternatives.
 
  #6  
Old 04-29-10, 05:52 PM
airman.1994's Avatar
Member
Join Date: Dec 2005
Location: VA
Posts: 5,491
Upvotes: 0
Received 8 Upvotes on 8 Posts
  #7  
Old 04-30-10, 11:30 AM
E
Member
Thread Starter
Join Date: Mar 2009
Location: San Antonio, TX
Posts: 33
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks for the visual...but I had a pretty good idea of what it looks like. Any thoughts on why Goodman would have stated that a smaller diameter line would be OK? Any others care to chime in? Thanks All!
 
  #8  
Old 04-30-10, 12:01 PM
Gunguy45's Avatar
Super Moderator
Join Date: Dec 2007
Location: USA
Posts: 19,281
Received 8 Upvotes on 8 Posts
Makes me question if he even called them? That's a 1/4" (22%) reduction in diameter...hard to believe it was engineered one way but they say it's ok to deviate?

No HVAC tech...but I would think that would have a big effect on efficiency and possibly impact any warranty in the future.

Get it in writing from Goodman.....
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: