DIY Home Improvement, Remodeling & Repair Forum > Appliances > HVAC > HVAC for 2nd Story Addition?




Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old 07-10-2007, 02:10 PM  
watersda
Junior Member
 
Join Date: Jul 2007
Posts: 6
Default HVAC for 2nd Story Addition?

I am in the process of designing a 2nd floor addition to my 1500 sf ranch. The current forced hot air, gas furnace is in the basement. I plan on having it replaced with a new Trane with central air. Will I be able to have one unit to heat/cool the 1st and 2nd floor? Can I have the duct work extended up through the 2nd floor into the attic and branch off to the seperate rooms from there? Or, will I have to have 2 seperate HVAC units, 1 for each floor? I am estimating $10-15K, am I in the ballpark?
Any comments/suggestions would be appreciated.



__________________
watersda is offline  
 
Reply With Quote Quick reply to this message
Old 07-11-2007, 05:37 AM  
CraigFL
Senior Member
 
Join Date: Mar 2006
Posts: 409
Default

After owning several 2 story homes and ranches, I prefer two seperate units for two story homes. There are air flow/mixing problems with two story homes that are easily overcome by two units. And... if one unit goes out, you always have a backup.



__________________
CraigFL is offline  
 
Reply With Quote Quick reply to this message
Old 07-20-2007, 07:58 AM  
subcoolman
Junior Member
 
Join Date: Jul 2007
Posts: 2
Default

As with many other things in life, "It depends". I'm new here (first post), but I've been in the HVAC industry for over 10 years.

Whether air will reach the second story of your addition really depends upon proper ductwork design and sizing. If the ductwork is sized, designed, and installed properly there is no reason why this wouldn't work for you, but most Residential HVAC installers don't want to take the time and/or effort to do this.

Find a "good" HVAC Contractor, perhaps even a light Commercial one, and ask them to do a ductwork sizing analysis and layout for you. Then, install the ductwork as sized- no cutting corners.

Proper design can make a world of difference.

__________________
subcoolman is offline  
 
Reply With Quote Quick reply to this message
Old 09-10-2007, 09:43 AM  
glennjanie
Senior Member
 
Join Date: Mar 2006
Posts: 2,992
Liked 2 Times on 2 Posts

Send a message via AIM to glennjanie
Default

Hello Watersda:

It looks like you and Subcoolman are both new to the Forum; Welcome to both of you. Can't you just picture Subcoolman with his mask, cape and a big S on his tee shirt. A timid little lady with her hands folded, saying "My Hero".

I personally vote for Subcoolman's answer for your problem; he has covered the bases and knows what he's talking about. Cooling two levels is a challenge for an A/C man but most of them know they can do zone heating and cooling by proper duct sizing and regulating dampers or by using two systems. Naturally the single system is the lower price.

Glenn

__________________
glennjanie is offline  
 
Reply With Quote Quick reply to this message
Old 09-21-2007, 07:54 AM  
watersda
Junior Member
 
Join Date: Jul 2007
Posts: 6
Default

Update:
I had 3 local trane dealers come to give me qoutes. 2 of them did, 1 came and looked at the job, but ended up blowing me off for the quote. The 2 that did were very close to each other. 1 qouted XR12 Central Air units with the old refrigerent. I asked him to reqoute with the same model #'s I got from the other dealer and they were within $800 of each other.
The concensus was 2 seperate units.
1st floor: Replace downstairs furnace with high efficiency trane (95%) and a 2.5 ton trane XR14 central air unit, extend a few ducts. ~$8000
2nd floor addition: 80% eff. trane furnace in attic, all new ductwork, 2 ton XR14 central air unit. ~$12,000

~$20,000 total, installed. Seems reasonable?

__________________
watersda is offline  
 
Reply With Quote Quick reply to this message
Old 09-21-2007, 11:05 AM  
glennjanie
Senior Member
 
Join Date: Mar 2006
Posts: 2,992
Liked 2 Times on 2 Posts

Send a message via AIM to glennjanie
Default

Hello Watersda:
Call your neighborhood Carrier dealer(s) and ask them the same questions and ask for bids. If any HVAC contractor talks about any flex duct, take him off your list and ignore his bid.
It is not that big a deal to use one unit for both floors with zoned duct work and the single unit will be less expensive to buy and more efficient to operate. Some dealers have a computer program to design the system for them and can do a magnificent job for you. The $20,000 bid is far out of line.
Glenn

__________________
glennjanie is offline  
 
Reply With Quote Quick reply to this message
Old 10-03-2007, 08:18 PM  
gwliston
Junior Member
 
Join Date: Sep 2007
Posts: 5
Default

$20,000 - ouch! Get more quotes.

I've had several houses - ranch and 2 story - in places with similar climates to Schenectady. I've never needed a separate AC for the upstairs. You're adding 1500 sq ft or less, right? So, total squares will be 3000 or less. That's not too much to ask from a single furnace/AC unit. Once it's installed, a little trial-and-error experience will tell you how to set the dampers for the heating and cooling season.

When you're looking around, I suggest that you don't get "target fixation" on a particular line or model. Unless, of course, you like spending money. My guess is that you should be able to get one monster system for less than $10K, and two smaller systems for less than $15K. The $20K quotes may actually be the right deal for you, but you need to be sure.

'nuther Glenn



__________________
gwliston is offline  
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options

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 On
Refbacks are On


Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
Correct way to handle HVAC in attic? pjcampo HVAC 6 01-13-2009 05:52 AM
1 Story Footer to 2 Story Footer CA Willy Bricks, Masonry and Concrete 1 08-18-2008 07:40 AM
HVAC direct vent question Mom2bac HVAC 6 02-24-2008 07:01 PM
2nd story addition bhm25 General Home Improvement Discussion 2 01-21-2007 04:32 PM
Help with Addition. tooltime General Home Improvement Discussion 4 06-20-2006 09:35 PM