What temperature to use for cooling degree day?

[sailoday28]

What is a realistic temperature to use for CCD? I will be using the hours in conjunction with SEER to estimate future cost for KW-HR for a heat pump. Also how many years back should be included, ie 2012,2011 ,etc?

Thanks

 

[DRWeig]

Get yourself a TMY (typical meteorological year) weather file for your location, free from US DOE at:

http://doe2.com/index_wth.html

The TMY is a good statistical average, and it's the standard for energy analysis work.

Here's a discussion that's pretty accurate:

http://en.wikipedia.org/wiki/Typical_meteorological_year

There are lots of conversion programs to turn that TMY file into readable data. This one from the U of Wisconsin Solar Energy Labs puts the TMY directly into Excel:

http://sel.me.wisc.edu/trnsys/weather/tmy2data.htm

As for your base temperature, the typical one we pick is 65°F for residential low-rise buildings, 50°-55°F for commercial and institutional spaces (except health care occupancies). Degree days is pretty meaningless for hospitals or any other facility that is heavily internally loaded.



Best to you,

Goober Dave

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[EnergyProfessional]

I don't see how cooling degreeday and SEER will help.
First, for cooling you also would need wetbulb degree days and solar radiation. Second, your building, internal loads etc. play a role.
a 8760-hour energy simulation is a must to even have a chance, and event hat is based on many assumptions.

 

[sailoday28]

Sorry, I will use CDD for summer kw-hrs.
CDD*24 = hours.
DesignTons*hours /SEER =kw-hr
Regards

 

[MintJulep]

Use TMY and an hourly building occupancy and use schedule.

Degree days are just too course to return anything meaninful.