[Bldg-sim] Balance point temperature for houses

[Vikram Sami]

David,
Thanks for pointing that out - there is a typo in the paper. The formula
should read
 
 
QSOL + QEQU + QPPL = (M*CP + UABLD) x (TDES - TBAL)

The software uses the correct formula though. At this point we (Lord
Aeck Sargent & The Rocky Mountain Institute) use this as a schematic
design tool on quite a few projects, and find its quite useful. The plan
is to ultimately make this available freely (I would like to make it
work with the new TMY3 files before I start giving it away though). 

Once again - thanks for pointing out the typo - sharp eyes (sharper than
mine when I was typing out the paper at 2am). 

Vikram Sami, LEED AP 
Direct Phone 404-253-1466 | Direct Fax 404-253-1366 

LORD, AECK & SARGENT ARCHITECTURE
1201 Peachtree Street NE, Suite 300, Atlanta, GA 30361 
Responsive Design * Technological Expertise * Exceptional Service 
www.lordaecksargent.com 

Please don't print this email unless you really have to. 
In the United States, we use enough office paper each year to build a
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distance from New York to Los Angeles. 

~ Wisconsin Department of Natural Resources, "Recycling Facts and
Figures," PUBL CE-163, 2002. 

 

________________________________

From: David Bryan [mailto:DBryan at AmerIndian.com] 
Sent: Friday, May 09, 2008 2:16 PM
To: Vikram Sami
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Balance point temperature for houses


Vikram -
The balance point tool looks extremely useful during the building design
stages when it wpould be much more practical than a detailed energy
model.
I look forward to its availability.
Do you intend it to be for commercial as well as residential buildings?

In that case it would need a way to input code-required minimum
ventilation rates with some heat exchange options.
The formula Qint = M*Cp UAbld x (Tdes-Tbal) looks odd. Maybe I don't
understand the units, but should that be Qint = (M/hr*Cp + UAbld) x
(Tdes-Tbal)?
Thanks,
Dave Bryan 
AIA, LEED 

AmerINDIAN Architecture 
Suite 100, 475 Cleveland Avenue North 
Saint Paul, Minnesota, 55104    USA 

651-644-1586 phone 
651-644-7172 fax 

dbryan at amerindian.com 
www.amerindian.com 

<http://www.amerindian.com/> <http://www.amerindian.com/> 


Vikram Sami wrote: 

	 
	I have been working on developing an analysis tool that extends
the
	building passive envelope season based on a dynamic balance
point
	analysis (see attached)
	
	
	
	Vikram Sami, LEED AP
	Direct Phone 404-253-1466 | Direct Fax 404-253-1366
	
	LORD, AECK & SARGENT ARCHITECTURE
	1201 Peachtree Street NE, Suite 300, Atlanta, GA 30361
	Responsive Design * Technological Expertise * Exceptional
Service
	www.lordaecksargent.com
	
	Please don't print this email unless you really have to.
	In the United States, we use enough office paper each year to
build a
	10-foot high wall that's 6,815 miles long or two and a half
times the
	distance from New York to Los Angeles. 
	~ Wisconsin Department of Natural Resources, "Recycling Facts
and
	Figures," PUBL CE-163, 2002.
	
	
	-----Original Message-----
	From: bldg-sim-bounces at lists.onebuilding.org
	[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of
Chris
	Balbach
	Sent: Wednesday, May 07, 2008 11:27 AM
	To: bldg-sim at lists.onebuilding.org
	Subject: Re: [Bldg-sim] Balance point temperature for houses
	
	Dr. Abaza :
	
	The TREAT (Targeted Residential Energy Analysis Tool) whole
building
	energy simulation software package can determine a building's
balance
	point (both heating and cooling) given the building description.
One can
	construct a 'simple' model of a typical house in about 15
minutes, and
	TMY2 weather files for all 50 states are included for driving
the model.
	It would be pretty simple to make some parametric runs varying
both
	climate and envelope /infiltration to produce a range of balance
point
	temps. We have found both insulation levels and air infiltration
	(tightness of the envelope) often have the greatest effect on
the
	balance point of a given structure, along with the temperature
setpoints
	used for heating and cooling. Significant internal gains, of
course, can
	also drive the balance points.
	
	A 30 day fully functional version (free download) of the TREAT
software
	is available from http://www.treatsoftware.com
	
	Best,
	
	_Chris
	
	Chris Balbach, PE, CEM
	Vice President of Research and Development
	124 Brindley Street, Suite 4, Ithaca, NY 14850
	ph: (607)-327-1647
	http://www.psdconsulting.com
	http://www.treatsoftware.com
	
	Michael Blasnik wrote:
	  

		In my experience from analyzing utility usage data with
a floating 
		balance point, the typical effective heating balance
point in US homes
		    

	
	  

		will usually be in the range of 54F - 62F (for true
heating climates).
		    

	
	  

		Newer homes are usually closer to the low end of the
scale while older
		    

	
	  

		homes are on the higher end. Electrically heated homes
tend to be on 
		the lower end but it's not clear how much of that
difference is the 
		effects of vintage/thermal integrity vs. lower
thermostat set points 
		or zoning.
		
		There may be some published results in ACEEE summer
study proceedings,
		    

	
	  

		but I can't recall any specific reference.
		
		Michael Blasnik
		
		
		----- Original Message ----- From: "Abaza Hussein"
<ahussein at spsu.edu> <mailto:ahussein at spsu.edu> 
		To: <equest-users at lists.onebuilding.org>
<mailto:equest-users at lists.onebuilding.org> ;
		<bldg-sim at lists.onebuilding.org>
<mailto:bldg-sim at lists.onebuilding.org> 
		Sent: Tuesday, May 06, 2008 3:52 PM
		Subject: [Bldg-sim] Balance point temperature for houses
		
		
		    

			Could you please help. Is there any recent data
or survey about the 
			balance point temperature of homes in the US. Is
the 65F still 
			applicable?
			I appreciate any input.
			Dr. H. Abaza
			ECU
			      

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