Part 2 Flashcards
Elements affecting building retrofits
1- policies and regulations.
2- retrofit technologies.
3- human factors.
4- uncertainty factors.
5- client resources and expectations.
6- building specific information.
Policies and regulations
- energy efficiency standards.
- minimum EE requirements for retrofitting existing building.
Governments may offer financial assistance to building owners.
Client resources and expectations
- identify objectives and targets of the project to help decide the best retrofit measure.
- for clients, deciding whether to invest in the retrofit or not is always challenge because EE investment decisions are complicated.
- payback period is the most widely used decision making rule.
- high capital investment cost leads to more energy saving.
- low capital investment have low energy savings.
Building specific information
Geographical location
Building type
Size
Age - age of people inside the building
Occupancy schedule.
Operation and maintinance
Energy sources - to know COP
Utility rate structure.
Building fabric
Services system
Uncertainity factors
Estimation of things that we don’t think will happen, helps to select the best retrofitting measure and maximise building EE during the whole life span of the building.
Human factors
Comfort requirements: temp, humidity
occupancy regimes: schedules.
Management and maintenance
Activity in the building
Access to control: control parameters like temp and humidity, control lighting
- change in occupant behaviour, controls, and comfort range lead to high energy savings that can be done with no or low cost.
Retrofit technologies
Energy conservation measures used to promote EE and sustainability.
- energy efficient equipment, advanced controls, RE, change or energy consumption patters, advNced HVAC technologies.
Economic payback, complexity and ease of implementation should taken into account.
Important issues related to building retrofitting
- each building is unique, retrofit measures in one building doesnt apply for other buildings.
- using all ecm doesnt always have benefits, maybe using one is better.
- selection of ECM is multi objective optimisation problem.
Multi-objective optimization
Scientific area that offers a wide variety of methods with great potential for the solution of complicated problem.
Optimization problem can be developed by using:
1- model based approach.
2- model free approach.
Model based approach
- energy simulation models or tools used to estimate energy savings of different ECMs.
- optimization technique is used to search for optimal solutions.
- the analysis of energy savings should recognise the modelling mismatch
في خلل لانه في انبوت واوتبوت
Model free approach
- dont use models.
- expert system.
- richness of knowledge and experience of expert system.
Have high risk and errors
مش دقيق كتير
Retrofit strategy consists of
1- strategic planning and models, tools selection to provide necessary information and resource support for retrofit. And to effect retrofit strategies with highest added value.
2- major retrofit activities in the whole building.
Retrofit technologies three categories:
1- supply side management: electrical system, renewable energy.
2- demand side management: reduce heating and cooling demand, energy efficient equipment, low energy techs.
3- change of energy consumption patterns: human factors.
Demand side management
1- heating and cooling demand: retrofitting building fabric, advanced techs like air tightness, window shading, cool roof, replace glazing.
2- efficient equipment and low energy techs: advanced control(bmc,NBX), natural ventilation, heat recovery, thermal storage, energy efficient equipment, lighting upgrade
