What System Do I Need

[californiadreamer]

We are adding 1,400 sqft to our existing 1,600 sqft house. The addition will be on the 2nd floor. How large a system should we be looking at? Would it make sense to have two different zones, one for the upstairs and one for the downstairs?

[Jultzya]

System sizing (http://hvaccomputer.com/talkref.asp)

2 systems or one system with two zones.

Helpful link (http://www.hvac-talk.com/vbb/showthread.php?threadid=38790)

[dpatty]

Try using the hvac calc software at the top of the page to find out what size equipment you will need. It is always best to have zone system or a separate system when you have a 2 story home.

[beenthere]

1400 sq ft addition, put a second unit in for it.

[dan sw fl]

Originally posted by californiadreamer
We are adding 1,400 sq ft to our existing 1,600 sq ft house. The addition will be on the 2nd floor. How large a system should we be looking at? Would it make sense to have two different zones, one for the upstairs and one for the downstairs?

TWO SYSTEMS ARE REQUIRED
Factors which determine size:
Location ___
___ Location
______ Location
Design temperature is 101'F for Bakerfield
................... 95'F for Pasadena
................... 83'F for San Francisco

House and Window Orientations ___
... 50 feet x 28 feet or so
.50 or ___ feet faces West with 60 or ___Sq. Feet Windows
.50 or ___ feet faces East with 60 or ___
.28 or ___ feet faces North with 40 or ___
.28 or ___ feet faces South with 40 or ___

Window type__ Shading coefficient
Total Window area ~ 200 to 250 Sq. Ft.
___ Overhangs
___ Curtains or Blinds

Based on 75'F inside temp and above,
you may need 3 or 3.5 tons for Bakersfield.
like ~ 2.5 or 3 tons for Pasadena
like only 2 tons for San Francicso with 83'F design temp.

Other locations and orientations than asusmed
Who Knows?

In other words, ALL of the SPECIFICS ARE REQUIRED.

[Edited by dan sw fl on 10-22-2005 at 07:43 AM]

[californiadreamer]

Thank you to all those who replied. It sounds like I should get two systems. If I need a total of 3 tons, I assume I need two 1.5 systems? Is that correct?
Also, I have heard that leaks in the ducting system is very common how do I check whether my contractor has done a good job installing the ducts?

[californiadreamer]

Dan, Thank you for such a thorough reply. It sounds like I should get two systems. If I need a total of 3 tons, I assume I need two 1.5 systems? Is that correct?
Also, I have heard that leaks in the ducting system is very common how do I check whether my contractor has done a good job installing the ducts?

TWO SYSTEMS ARE REQUIRED
Factors which determine size:
Location ___
___ Location
______ Location
Design temperature is 101'F for Bakerfield
................... 95'F for Pasadena
................... 83'F for San Francisco

House and Window Orientations ___
... 50 feet x 28 feet or so
.50 or ___ feet faces West with 60 or ___Sq. Feet Windows
.50 or ___ feet faces East with 60 or ___
.28 or ___ feet faces North with 40 or ___
.28 or ___ feet faces South with 40 or ___

Window type__ Shading coefficient
Total Window area ~ 200 to 250 Sq. Ft.
___ Overhangs
___ Curtains or Blinds

Based on 75'F inside temp and above,
you may need 3 or 3.5 tons for Bakersfield.
like ~ 2.5 or 3 tons for Pasadena
like only 2 tons for San Francicso with 83'F design temp.

Other locations and orientations than asusmed
Who Knows?

In other words, ALL of the SPECIFICS ARE REQUIRED.

[Edited by dan sw fl on 10-22-2005 at 07:43 AM] [/B][/QUOTE]