Building Energy Modeling (BEM) Software enables us to design energy savings solutions as well as evaluate their interaction and impact on the entire building.
Why Building Energy Modeling? The answer is complexity. Building operations and energy consumption involves a lot of interacting, continually changing, moving parts. In addition to the intricacies of the exterior structure itself, it sometimes pales in comparison to everything taking place on the inside. Not to mention the impact when weather is added to the mix.
Utility Use & Cost Analysis with Weather Impact Correlation
Building Energy Modeling (BEM) Design Simulation
The analysis includes a thorough profiling and analysis of your actual utility bill data including electricity, natural gas, LP, fuel oil, water and sewer. Depending on your specific rate structure this may not be as simple as dividing your total bill by total use. For example, in addition to electricity kWh costs, other billing components can include kW/kVa demand, fuel cost recovery, power factor, rate tiers, riders, taxes, discounts, etc.
The final step in utility bill assessment is the correlation of utility use and cost profiles to ACTUAL weather degree-day data over the same corresponding billing period.
How does weather impact your facilites energy use?
The above graph is an illustration of the kW electrical demand profile in relationship to the increase in seasonal cooling degree days. The data shows a direct correlation between hotter outside temperatures and the significant increase in kW electrical demand, caused by air conditioning equipment. This leads us to investigating AC equipment & distribution efficiencies. Additional items that may be considered include ways to reduce the amount of heat gain (load) in the building envelope itself or reduce internal (intrinsic) heat load, coming from lighting, computers, equipment, etc.
Simulation analysis provides a before and after, energy use building profile based on the performance, operation and interaction of the building envelope and all of the systems within the building.
Building Energy Modeling (BEM) involves compiling and inputting the following data, building structural and floor plan design parameters along with all building systems, lighting, heating & cooling, domestic hot water, equipment and plug load. Additional pertinent information includes; local weather/climate data, number of occupants, operating schedules including temperature, time and occupancy. The source for this information is available from a combination of blueprints, spec books, utility bill analysis and comprehensive on site data collection.
Building Energy Modeling
Output Results
Some examples where we utilize Building Energy Modeling Simulation Software:
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ECM - Energy Savings Calculations
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ECM - Performance Comparisons
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Insulation Impact on Heating & Cooling
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Window Replacement - Cooling Load
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Computer/Server Room Load Calculation
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Heating & Cooling Equipment Sizing
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Building Space Design Load Calculations
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Lighting Retrofit - Heating & Cooling BTU per Hour Load Calculation
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Kitchen Equipment Fuel Conversion
Heating & Cooling Degree Day Data For Your Location
Energy BTU Content & Average Cost per Million BTUs (MBTU)
Insulation & Thermal Mass Impact on Building Control - Cooling
Buildings constructed of concrete and brick masonry walls have a built in energy saving advantage known as thermal mass. Thermal mass is the ability of a material to store and later release heat. The graph above illustrates the impact of insulation on the principle of thermal mass during the summer. This illustration is unique in that is shows both a positive and negative impact of thermal mass.
In the Baseline Building illustrated in (blue) the AC shuts off at 2:30 am, restarts at 6 AM and operates until night setback at 6 PM. The AC unit in the Baseline Building operates 2.5 hours less than the insulated building but uses far more energy throughout the 24 hour period.
In the Insulated Building illustrated in (yellow), the AC shuts off at 5:00 AM, restarts at 6 AM and operates until night setback at 6 PM. The AC unit in the Insulated Building operates 2.5 hours more than the Baseline Building due to the release of the heat energy stored in the thermal mass of the interior layer of concrete block wall. In this instance the added insulation in the concrete/brick masonry wall increased AC energy use & cost between 2:30 AM and 5:00 AM.
This Peak Design Cooling Load profile also illustrates the value and performance of Building Energy Modeling Software (BEM).