ENERGY SAVING MEASURE #1: JABURKOVE
The ESM #1 has been implemented and optimised in the building on the street J.JabUrkové 1,3,5, Havirov.
AFTER energy saving measure consists in system for remote readings of water and heating energy consumption in individual apartments. The system calculates the heating energy consumption per apartment with degree day method. Consumption data of individual apartments are visualised to users on internet web portal in charts and tables. The system serves to continuously inform tenants about their consumption and it can ensure fair billing of heating energy and water costs among apartments – the system is suitable for older apartment houses (“prefabs”) with vertical heat pipelines. The system enables to detect immediately leakages (for example broken toilet) due to technical malfunctions and fraudulent conduct. The tool can bring savings about 5 up to 15% of yearly costs. The cost of smart metering system is about 8768 EUR per building. This amount has not be included in the AFTER project but is an investment part of the asset management plan of the SHO. The savings expected are about 5% per year (first year annual savings: 796 EUR. Water CW 10%, HW 5%, first year annual savings: CW: 404 EUR, HW: 465 EUR).
The solution has already been installed in Havirov pilot site and in several houses (condominiums, housing co-operatives) in Praha. The system functions very well and can be implemented in any multifamily house that should have connection to the internet. The system has been optimised with energy saving tips in paper and electronic form and with monthly paper reports about consumption of apartment including benchmarking with other apartments in the building because not all tenants have access to internet.
During the testing phase the implementation of the system brought higher accuracy in metering water consumption. The difference between consumption measured on main building water meter and sum of consumptions on flat submeters very significantly decreased. The tenants also find useful the energy savings tips and monthly paper reports. Reduction of heating energy consumption was moderate because the heating energy costs were charged to the tenants according to area of apartments and this is not motivating for the tenants. The change of the heating energy costs billing system based more on consumption than surface will bring higher energy savings.
The solution has already been installed in Havirov pilot site and in several houses (condominiums, housing co-operatives) in Praha. The system functions very well and can be implemented in any multifamily house that should have connection to the internet. The objective of the AFTER project aims at improving this system with energy saving tips in paper and electronic form and with monthly paper reports about consumption of apartment including benchmarking with other apartments in the building because not all tenants have access to internet. The objective was clearly to enhance the expected 5% of savings concerning heating.
The costs for the additional AFTER optimization are about 1850 EUR.
The combination of the implementation of the smart metering system and its AFTER optimization lead us to and expected amount of 10 618 EUR. The analysis of normalized energy consumption after the AFTER optimization shows a notable reduction of 11,7% on the JABURBOVE Pilot Site.
From a consumption of 123 kWh/m²/y in the baseline period (without the implementation of the website and the tenants awareness process) we achieve a mean consumption of 109 kWh/m².y after the ESM optimization. This conclusion represents savings estimated about 24,648 MWh for the testing period (approx.. 126 EUR/dwelling).
During the testing phase the implementation of the system brought higher accuracy in metering water consumption. The difference between consumption measured on main building water meter and sum of consumptions on flat submeters very significantly decreased. The tenants also find useful the energy savings tips and monthly paper reports. Reduction of heating energy consumption was moderate because the heating energy costs were charged to the tenants according to area of apartments and this is not motivating for the tenants.
The change of the heating energy costs billing system based more on consumption than surface will bring higher energy savings.
ENERGY SAVING MEASURE #2: UZAVRENA
The Energy Saving Measur implemented in the UZAVRENA building consists in hydraulic balancing of the heating system and has been optimised with new scheme of hydraulic balancing.
The Czech legislation includes obligation of installation of thermostatic valves with secondary pre-setting in individual apartments and obligation of watching over at least differential pressure and flow rate in connecting point of the house. Obligations are determined in the Czech regulation no. 194/2007 paragraph 6 letter 1d.
MRA has optimised hydraulic balancing with regulation of the individual vertical pipelines and new better TRVs and regulation valve in connecting point. It simplifies maintenance and potential looking for defects. It ensures more equal pressures and flow rates in individual pipelines and can bring savings about 1-5%. During the testing phase the optimisation of hydraulic balancing of the heating system brought improvement of the thermal comfort and decrease of noise in the heating system.
During the testing phase the optimisation brought low energy savings estimated at approcimately 1,6% which represent approximately 3 MWh for the corresponding heating season.
The reason is that the heating season 2013/2014 was extremely warm (2343 HDD compared to 2680 – 5 years average HDD value). The response of the heating system with equitherm heating control is not flexible enough to efficiently cope with solar gains. The water in the heating system has higher temperatures than necessary and thus lower efficiency. The heating system was partly hydraulically balanced before (TRVs). The heating curve could not be analysed and adjusted to the optimum setting. The heat transfer station is the ownership of the energy provider HTS. Tenants have sufficient level of energy awareness but lack of motivation due to billing scheme.
Total incurred costs: 11.862,- EUR
With the total costs of 11862,- EUR and discount rate 0,75 % (Czech National Bank 2011)
The measure with 10 years life expectancy will lead to -4.934,- EUR NPV.
The IRR is …-8,4 %.
MRA has in total 29045 TRVs on radiators in the whole managed municipal housing stock. Individual houses are optimised with new TRVs and new improved hydraulic balancing of heating system gradually every year according to available financial sources.
On 11.4.2014 there are remaining 9705 TRVs that will be replaced with new TRVs in the following years and about 183 building sections that will be inspected and will be optimised with new solution of hydraulic balancing in the following years. In year 2014 there will be done new hydraulic balancing and replacement of TRVs for1.5 mil. Czech crowns (62 179 eur).
ENERGY SAVING MEASURE #3: TOLSTEHO
The ESM #3 is focused on global refurbishment that has been optimised with thermography measurement in order to check quality of installation of windows and balcony doors.
The TOLSTEHO building has been completely refurbished in 2009 with an additional external insulation and new windows. MRA spent for the implementation of the ESM 590.000,00 €.
In order to optimize this process, the AFTER project partners have implemented a thermography on the building in order to assess the efficiency of the building.
The thermography measurement revealed a lot of defects during installation of windows. There were air leaks around windows, under window sill and between window sill and window frame.
In order to correct these weak points and to reach a good level of performance for the refurbishment, MRA has implemented a quality process with its service provider in order to improve the air leaks around the 124 windows of the building:
– resealing and adjusting the windows.
– Tearing of resealing the interiors sills.
The optimisation reduces heat loss of the object by infiltration by about 10% which brings savings of heating energy in range of 3-5%. The estimation comes out from experience in metering tightness of building envelope (for example blower door test).
The normalized energy consumption before the implementation of the ESM is 186 kWh/sm/year after is 130 kWh/sm/year which lead us to a yearly reduction after and before the ESM of approximately 96,144 MWh.
This percentage of the heating energy reduction is well aligned with the previsions of the specific literature which evaluate in 20-30 percent of home heating bills reduce after the refurbishment of the external insulation. The optimization has guarantee to reach the highest level of performance for this optimization.
Conclusion from the testing phase is that thermography measurement improves quality of works done in refurbishment and can prevent heat losses. It should be done immediately after installation of windows and external insulation. Thermography measurement is very low cost energy saving measure that can be easily performed. Requirement of control with thermography measurement or submission of the thermography report should be included in the contract with refurbishment subcontractor. The technical staff should be equipped with thermography camera in order to check works on construction and point out problems to workers.
The first thermography diagnosis cost 216,00 €.
The repair of the weakness points of the windows have been done for free by the contractor in the frame of the guarantee period in only one apartment.
As matter of fact, this ESM can be considered as highly economical. The most difficult part aims at convincing all the tenants of the building to accept some indoor modifications after the end of the works implemented during the refurbishment activities.