TM65

Question 1

Document outline

Answer 1

Outlines the need for assessments of EC of products linked to mechanical, electrical, and public health (MEP) systems and to increase knowledge in WLC in MEP systems. It covers the whole life cycle excluding operational aspects. MEP EC can be significant in a building lifetimes due to materials that MEP equipment are made of and high replacement rates.

Question 2

Document Function

Answer 2

Document provides guidance on how to use EPDs for MEP products. Where EPDs are not available, doc provides guidance on how to estimate the EC of MEP products. enables initial conservative estimates of EC to be made when EPD data not available

Question 3

Context

Answer 3

Construction industry long focused on operational carbon emissions and much less attention to emissions related to other life cycle stages

Question 4

Methods of reducing MEP impact

Answer 4

Natural ventilation
highly efficient equipment
low refrigerant GWO and leakage rates
long lifetimes
lower weight
low EC materials
products and components that can be demounted and reused
products that can be disassembled, and materials recycled
easily accessible for inspection, maintenance and replacement.

Question 5

Estimated overall impact of MEP systems

Answer 5

could account for 2-27% of EC of new build schemes
could account for 75% of EC of retrofits

Question 6

Limitations of MEP EC reporting

Answer 6

MEP products are complex and comprise of multiple materials so EPD data is scarce

Question 7

Coverage

Answer 7

Heating
Cooling
Ventilation
Lighting
Electrical
Public Health
not included: non standard equipment like photovoltaics

Question 8

Building vs Product

Answer 8

At a product level, EC does not include emissions associated with B5 (replacement) and B5 (refurbishment). Building level covers everything. if components are replaced within the product service life, then this is included in B3

Question 9

EC impact in MEP design

Answer 9

large proportion of EC from MEP products are associated with A1-A3 (approximately 92%) due to fact majority of MEP components are made of metals, electronics and plastics and have a complex supply chain.
MEP products usually have a relatively short lifespan which means that they need to be replaced multiple times so if the analysis was at a building level, Stage B would become significant

Question 10

Circular Economy principles for building services

Answer 10

Joint venture: incentivizes the installer to optimize operational performance, overcoming budgetary constraints during commissioning
Universal buildings: flexible building where potential uses for building clearly defined
Passive: eliminating requirement for active MEP systems in building. e.g natural ventilation systems, maximizing use of natural daylight, use of solar shades to minimize heat gains
Preloved: pre-used, remanufactured, refurbished, or new equipment fabricated from recycled materials.
Recover: reduced consumption of primary resource flows such as energy, water and waste through recovery

Question 11

Refrigerant leakage mitigation

Answer 11

Reducing volume of refrigerant used (refrigerant charge) through passive design measures and reducing size of equipment. split systems enable hot and cool air to be distributed at first by refrigerant and then by water - reducing refrigerant in system.

specifying equipment with low GWP refrigerants: CFCs and HCFCs are banned by European Comission. HFCs are regulated in Europe. HFO +natural/hydrocarbons such as propane, ammonia, CO2, water have much lower GWP

Ensuring low leakage rates: good maintenance regimes to avoid overpressure., pipework with brazed connections rather than flare, controls to detect leakage.

Refrigerant should be 100% recovered without decreasing system performance.

Question 12

Basic Calculation Method

Answer 12

1. A1 emissions - multiplying weight of each material in the product by its EC coefficient. info must be provided for 95% of product weight at least. any remaining material not disclosed is steel.
2. • EC associated with any components that re replaced, add result to step 1. if no info from manufacturer a 10% of A1 is used.
3. Scale up to account for remaining life cycle stages either 1.3,1.4 or 1.6 depending on complexity of product (accounts for A2, A3, A4, C2, C3, C4.
4. A conservative buffer factor of 1.3 to provide an adjustment to the simplicity of the approach
5. emissions associated with refrigerant leakage -annual leakage rate * quantity of refrigerant * GWP of refrigerant
6. sum all values together
7. report the results by completing the reporting form

Question 13

Mid Level calculation method

Answer 13

Sections A and B from the manufacturer form

1. product weight,
   material composition breakdown 95%,
   type and quantity of refrigerant within product,
   product service life CIBSE guide M should be used if no info
   assumed proportion of factory energy use associated with product (kw-h)
   final assembly location
2. calculate A1,2,3,4 of product
3. calculate stage C emissions of product
4. calculate B3 (repair)

Question 14

Requirement for EPD comparison

Answer 14

Unit needs to be equivalent between the EPDs e.g GWP per meter length for a 30 year service life.

what is excluded from calcs is the same

any life cycle stages excluded are the same

impact of construction works are taken into account are the same

assumptions relating to environmental impact of materials must be consistant between EPDs such as biogenic carbon contant, carbonation, net calorific value