Hot water pumps (baseline)

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Hello everyone,

User's manual for ASHRAE 90.1 says "For systems 1,5 and 7 (except for
purchased hot water or steam), the baseline building design hot water pump
power shall be 19 W/gpm". (page G-30)

I am confused if I have to use the proposed pumps in case I have purchased
hot water.

The chilled water pumps are always (as i understand) modeled at 22 W/gpm.


Thanks and Best Regards,


Varun Kulkarni , M.S. , EIT

varun kulkarni's picture
Joined: 2011-09-30
Reputation: 1


If you have purchased hot water in the proposed building and the project
is pursuing LEED certification (which I assume it is) you need to use
USGBC's Treatment of District or Campus Thermal Energy in LEED V2 and
LEED 2009 - Design & Construction. I've attached it as a reference.
You basically have two options: 1.) building stand-alone scenario where
only the downstream equipment is modeled and hot water is
metered/purchased, or; 2.) aggregate building/DES scenario where the
upstream equipment with its efficiencies or lack thereof are modeled in
the proposed design against 90.1.


Andrew Craig PE, LEED AP

Andrew Craig2's picture
Joined: 2011-10-02
Reputation: 0

Thanks Andrew,

I did read this and we are according to this i have to change my system type
to 7 from system 5 as I have district heating and cooling.
But I am worried about the hot water pump W/gpm specifically.
Should I just or Can I just go ahead and use 19 W/gpm.

varun kulkarni's picture
Joined: 2011-09-30
Reputation: 1