Dear Group,
As you know additional requirements from LEED led to purchased heat water coils being substituted for furnis heat coils in some unitary systems. 90.1-2007 therefore had requirements for the hot water pumps only for systems that normaly have hot water, such as 1, 5 and 7.

Consider that I am using 90.1-2007, but have purchased heat...as there is no pump requirement, should I

1) use that of 90.1-2010
2) use the proposed case pump power and scale the rated pressure rise acordingly with the baseline auto-sized flowrates and the required motor efficiency.

I vote for 2) as I'm using 2007 consistantly. I tested it with the 2010 requirement and the pump power would decrease by about 20%.

Kind regards,

Jean.