Tools: S.D.E.M.

 

Introduction

The purpose of this section is to introduce the S.D.E.M. software used, explain why the use of an energy targeting tool is an essential part of our methodology, as well indicate the assumptions taken during the progress of S.D.E.M. modeling.

Why S.D.E.M. ?

One of the first obstacles the team faced in defining the path that leads to a carbon neutral community was how do describe the housing stock of the case study, with respect to a greater methodology that can be applied to any community that aspires to become carbon neutral.

Initially the team thought that the best way to describe and analyze the building stock was simply to model each house. Later on, this thought was rejected due to time limitations. The team has decided to use S.D.E.M (Strathclyde Domestic Energy Modeling) tool developed by the University of Strathclyde for the Scottish Executive. In brief, S.D.E.M. is a housing stock energy targeting tool that can provide information regarding the annual energy delivered to a specific housing stock and the associated carbon emissions. Its function is based on the classical S.A.P. (government’s Standard Assessment Procedure) analysis but the results database originates from a series of ESP-r (dynamic) simulations.

After the team has finished with the site survey in Riverside (case study), the building stock database has been defined. Due to the outstanding degree of freedom of the building stock in terms of modeling (build period, house types, size of houses, type of glazing, heating system details, fabric improvements, type of appliances, etc) the team has decided to model the building stock of the community varying 6 essential parameters and assuming the remaining as common among community's building stock. Thus, the S.D.E.M. modeling was set for:

• Each Build Period
• Each House type
• Type of Glazing of each house
• Number of rooms in the house
• Size of rooms in the house
• Type of Ceiling (Victorians have a higher Ceiling than new Builds)

Regarding the parameters indicated below, we assumed that that these were the same among the community:

• Main heating fuel
• Type of lighting (low energy or filament)
• Attics
• Main heating system and water heating system type and installation date
• Ventilation
• Fabric upgrades and installation date
• Etc...

After having the building stock database modeled and ready, the team was able to proceed to the next step of the methodology (Reduction). Modeling this step was easier due to the flexibility and the friendly user interface of S.D.E.M. Two scenarios were created and modeled: the base case scenario, which describes the current state of the building stock in the community, and the best case scenario which represents the summary of the recommendations we made, covering fabric improvements and the use of efficient boilers use among others. for more information regarding these improvements can be found in case study.

Results:

The results section in this web report, is a quantification of the recommendations made for the community and are presented with respect to the annual energy consumption, the associated carbon dioxide emissions as well as the cost and payback period of these recommendations.