Hello,
I am working on a New Construction project - a community center, certifying under LEED v4.
I am pretty new with LEED projects and trying to identify whether the HVAC systems meet this credit.
The project has two types of systems Fan coil system - Carrier 25HCC548A003 & FV4CNF005L00 and spilt system - RAV-SP-180KRT-UL & RAV-SP-180AT2UL.
I am struggling with following things to complete LEED online calculator:
Qunit (tons),
Rc (lb/tons)
I tried looking on spec/cut sheet and was able to pull up Rc which is somewhere 3.1 and 4.8 and I am wondering whether I am interpreting this correctly or have to run some numbers?
Also, I do not know how to find Qunits?
any help will be greatly appreciable.
Roshni Lad
Project ManagerVCA Green
1 thumbs up
September 22, 2020 - 4:42 pm
Any help on my this question?
Daniel Davis
Project ManagerARCO National Construction
November 10, 2020 - 4:58 pm
Roshni-
Hopefully this helps (Mechanical people- call me out if any of this is incorrect)
Qunits is your tonnage, or your capacity to heat/cool. Typically, cooling always dictates, so your tonnage is frequently based off your cooling. You may hear things like a 1 ton unit, 1/2 ton unit for your house or an apartment "unit." On your cutsheets, you may not see the tonnage, but you may see the BTU per hour (BTU/h). The conversion is that 12,000 BTU/h equals 1 ton. The way I understand it is that "tons" are used just because it's an easier number to convey rather than BTU/h.
Regarding refrigerant charge (Rc), this should be listed on the cutsheet. What I'm trying to figure out is if my cutsheet typically lists the charge in lbs per ton, or if I need to do the quick math to get this. For example: I have a 1 1/2 ton ductless split system. It's charge is 4.5lbs. I do not know if this is 4.5lbs per 1 ton or 4.5lbs per 1.5 tons.