EA Pr 2 - Water Heating Equipment

Ciaran McCabe

Director

Passive Dynamics Sustainability Consultants

LEEDuser Basic Member

12 thumbs up

January 5, 2016

I have a 12kW electric water cylinder and a 12kW direct gas fired water heater. Can anyone please explain what I need to check to ensure the performance requirements comply with ASHRAE 90.1 2007 table 7.8. I dont understand the rating condition and performance required headings.

Post a reply

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Wed, 01/06/2016 - 15:19

The Subcategory or Rating Condition refers to the type of water heater and/or its storage capacity. The Performance Required is a formula used to determine the minimum efficiency of the equipment. So for a 12 kW electric, tank-type water heater the formula you use is 0.93–0.00132V EF. The note below the table identifies the variables V and EF. A clearer way to see this formula would be EF = 0.93–0.00132V. So put the volume of the tank in the equation and calculate the EF.

Ciaran McCabe

Director

Passive Dynamics Sustainability Consultants

LEEDuser Basic Member

12 thumbs up

Wed, 01/06/2016 - 15:44

Great thanks.