Practice Exercise: Building Envelope Systems

image

Starting Point:

The starting point model generated an energy model with a predicted mean EUI of 74.4 kBtu.ft2/yr.

image

Baseline Model

Implementing the following measures yielded a predicted mean EUI of 51.4 kBtu/ft2/yr:

  • Operating schedule: 12/5
  • Roof construction: R38
image

Implementation of Building Envelope Measures

In order to explore the potential impact of power and lighting measures versus building envelope measures, I will modify the following measures to attempt to drive down the predicted mean EUI:

  1. Plug Load Efficiency (the equipment and appliances that draw power)
    1. Lowered the plug load efficiency to 1.0 W/Sq.ft. (46.6 EUI mean)
    2. image
  2. Lighting Efficiency (based on the efficiency of the lighting fixtures)
    1. Set the lighting efficiency to 1.9 W/sf (55.2 EUI mean)
    2. image
  3. Daylighting & Occupancy Controls
    1. Implemented Daylighting & Occupancy Controls (54.5 EUI mean)
image

Even after implementing these energy conservation measures, I was unable to achieve a mean EUI of 54 or less. Therefore, I will implement more measures.

  1. Implement greater lighting Efficiency (based on the efficiency of the lighting fixtures)
    1. Increase energy efficiency to 1.1 W/SF (45.9 EUI mean)
    2. image

With these energy efficiency measure implementations, I was able to achieve a mean EUI of 45.9 kBtu/ft2/yr.

image
image

The Addition of Photovoltaic Panels

  1. Use the Insight Factor tiles to explore the impact of Photovoltaic Panels, varying the:
  2. 2207c0cdf8454bd9abc6577752add98df0ca1c3348ca40d7b5d0ffb89bfd973f47af243333f44236a254582d79a091bddc46c22ffe7f4edda4290137bd70ba656ddcd8c2389f4e849d0dbaee8b46e63f818e4c9445694fc9a6158a47d65a97ad0fcb735d264d43ed9b48908338926f4e
    1. Surface Coverage
      1. I adjusted the surface coverage to 60% and my EUI mean decreased quite a bit.
      2. image
    2. Panel Efficiency
      1. I adjusted my PV panels to reflect an efficiency of 20.4% (44.4 kBtu/ft2/yr)
      image

      c. Payback Limit (how many years you will allow for the panels to pay for themselves

      1. I modified the payback limit to a 20-year period and the EUI mean dropped significantly — 35.9 kBtu/ft2/yr.
      image

      It is evident that in order to achieve a low EUI mean, drastic implementations must be considered within a building model, such as: the thermal properties of the building envelope, plug load efficiency, and PV panel surface coverage to name a few.