Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-22-2011, 05:31 AM   #1
Newbie
 
Join Date: Sep 2011
Location: Motorcity
Posts: 3
Rewards Points: 10
Default

new furnace install


hello all, im planning on changing out my old carrier 130,000 btu furnace for a new 90,000 Goodman GKS90905DX, my house is about 1800 sq/ft so i need to figure out the size of the new plenum and the new cold air return transition.

my biggest concern is, this new furnace is about thirteen inches lower so my n-coil is going to have to be lowered which is a good thing. if i drain the system of refrigerant and cut the lines during the installation is there a time limit that i have before the system has to be recharged or can i wait till spring?

thanks for any input
Dom

dominic58 is offline   Reply With Quote
Old 10-22-2011, 06:39 AM   #2
Member
 
raylo32's Avatar
 
Join Date: Nov 2006
Location: Maryland (DC 'burbs)
Posts: 1,066
Rewards Points: 544
Default

new furnace install


Can't help on the transition but you want to minimize the time the lineset is open to the atmosphere. If you are going to leave it until spring you could cap the ends, evacuate and put in a little nitrogen. The coil is also a concern for oxidation. So really better to put it all back together now and get the air out.

Also, you shouldn't and don't need to "drain" the refrigerant. Look up how to pump a system down to capture the refrigerant in the outside unit.

If you lower the height of the furnace you will have to extend the lineset to reach the new coil position... or get a sheet metal spacer made to go between the furnace and coil to keep the coil at the height it is now. I just went through this and had a spacer made. Mine was a 7" difference.

Quote:
Originally Posted by dominic58 View Post
hello all, im planning on changing out my old carrier 130,000 btu furnace for a new 90,000 Goodman GKS90905DX, my house is about 1800 sq/ft so i need to figure out the size of the new plenum and the new cold air return transition.

my biggest concern is, this new furnace is about thirteen inches lower so my n-coil is going to have to be lowered which is a good thing. if i drain the system of refrigerant and cut the lines during the installation is there a time limit that i have before the system has to be recharged or can i wait till spring?

thanks for any input
Dom


Last edited by raylo32; 10-22-2011 at 06:41 AM.
raylo32 is online now   Reply With Quote
Old 10-22-2011, 06:57 AM   #3
Newbie
 
Join Date: Sep 2011
Location: Motorcity
Posts: 3
Rewards Points: 10
Default

new furnace install


thanks ray, yes ill need to have the lines extended, dont they have to be brazed vs. soldered? thanks for the tip on pumping down the system i just read a short article on it and think ill have a tech do this and seal the lines during this time and have him come back out and put it back together.
dominic58 is offline   Reply With Quote
Old 10-22-2011, 07:04 AM   #4
Member
 
raylo32's Avatar
 
Join Date: Nov 2006
Location: Maryland (DC 'burbs)
Posts: 1,066
Rewards Points: 544
Default

new furnace install


Yes, brazed. Finding small pieces of HVAC tubing isn't easy... they are typically sold in complete rolls of various lengths. But if you have a tech do the work he should have access to these items.
raylo32 is online now   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need Help With Furnace Install 67Dart440GT HVAC 6 10-20-2011 09:40 PM
Install Help on 75K BTU Garage NG Furnace live4spd HVAC 23 10-15-2011 08:58 AM
New Cased Coil - Install to Furnace - PICTURES!! hartkem HVAC 39 11-18-2008 02:45 AM
Installing a new Furnace, Shoud I install an A/C Coil Now? hartkem HVAC 1 11-10-2008 10:31 AM
How to install an expansion tank in my hot water furnace? DanBress HVAC 18 10-08-2008 04:57 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.