Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
What I've typically done for New Construction of residential buildings (mostly mid/high rise) is to follow the guidelines and calculator given by the ENERGY STAR Multifamily High Rise (MFHR) program. Basically, based on population classificaton it gives you a gallon of hot water per day and per occupant. Multiply that by the number of occupants and you'll get your baseline usage.
The tool spits out a peak flow rate and a fractional schedule to use with it, so you just have to create these in OpenStudio.
Not that for the water fixture definition object, as far as I know these values are for a target water temperature of 120F.
You can download the Performance Path Calculator on this page.
You should also take a look at the ASHRAE Handbook of Fundamentals - HVAC Applications (2015, 2011, 2007...), chapter called "Service Water Heating".
| | 2 | No.2 Revision |
What I've typically done for New Construction of residential buildings (mostly mid/high rise) is to follow the guidelines and calculator given by the ENERGY STAR Multifamily High Rise (MFHR) program. Basically, based on population classificaton classification it gives you a gallon how many gallons of hot water per day and per occupant. Multiply that by the number of occupants and you'll get your baseline usage.
The tool spits out a peak flow rate and a fractional schedule to use with it, so you just have to create these in OpenStudio.
Not Note that for the water fixture definition object, as far as I know these values are for a target water temperature of 120F.
You can download the Performance Path Calculator on this page.
You should also take a look at the ASHRAE Handbook of Fundamentals - HVAC Applications (2015, 2011, 2007...), chapter called "Service Water Heating".Heating". It has load profiles for different building types and a couple of different ways to size your heater.
