energy efficient hvac design for cold storage
DESCRIPTION
Energy Efficient HVAC Design for Cold Storage. Michael Huang, LEED AP Energy Engineer UC Davis. What’s an Ultra Low Freezer?. Ultra-low temperature (ULT) freezers reach -86 o F 400,000 units nationwide, 650-1000 at UCD. Why do we care about them?. - PowerPoint PPT PresentationTRANSCRIPT
Energy Efficient HVAC Design for Cold Storage
Michael Huang, LEED APEnergy EngineerUC Davis
What’s an Ultra Low Freezer? Ultra-low temperature (ULT) freezers reach -
86o F 400,000 units nationwide, 650-1000 at UCD
Why do we care about them?
Very low cost to store priceless samples
Samples are safer Energy is saved
If Your Freezer is Operating Efficiently...
Conventional Cooling Approach
heat load 1.08
Size plug load in kW, convert to kBtu/hr, convert to tons, then purchase AC unit (or CHW HX) to cool space
Q = 1.08 × m × ∆T X
Hot Aisle/Cold Aisle Arrangement
𝑄=1.08∗𝑚∗∆𝑇
UCD Primate Center
~50 ULT Freezers of various size/capacity
No economizer
Wall mounted BARD units
BARD units
Heat Gradient Across Room
Engineering Model
UCD Primate Center
Cold Aisle
Hot Aisle
Estimated Savings
Economizer annual (kWh)
No economizer
annual (kWh)Annual
savings (kWh)Annual savings
($)PG&E
IncentiveRetrofit
CostRetrofit Cost -
PG&E IncentiveSimple
ROI
76,095
180,057
103,962
$ $8,036
$ 24,951
$ 75,000
$ 50,049
6.2
Based off economizer savings & EER rating
Conclusion
Hot aisle/cold aisle containment Maintenance, maintenance,
maintenance!
𝑄=1.08∗𝑚∗∆𝑇
