Case Study: nZEC - New construction of 34 dwellings in Trollebergsvägen, Lund, Sweden
Name of organisation: Lunds kommuns fastighets AB
Stage of development: completed
Year of finalization: 2001
Type of project: construction
Area: urban
Scale: group of buildings
Type of building: Apartment in a block of five or less stories
Number of units/dwellings: 34
Tenure: social rental
Street: Trollebergsvägen 2,222 29
Postcode:
City: Lund
Region/ County: Skåne County
Country: Sweden
Last Update: 14.04.2015
Short Description
Construction technology is conventional with a frame made of concrete but with insulated curtain walls. Half the house is founded with the slab and half have heated basement with apartment storage. Roof construction is a cold unfurnished attic.
Thermal bridges are eliminated at all connections and air leakage. Ventilation is done with an exhaust system with air intakes behind the radiators. Forcing is possible in both the kitchen and bathroom. The warmth of the water-borne heating system will primarily from an exhaust /outdoor air supplemented with district heating.
The temperature is centrally controlled in each apartment and settled quickly. Heat and hot water use is measured and charged individually. Heat in the wastewater is recycled by a waste water heat exchanger to preheat domestic hot water. A solar heating system supplemented with district heating domestic hot water. Electrical equipment is energy efficient as well as control of fans and pumps.
Key Elements
Certification
57 kWh/sq.m heat, hot water and electricity for the building. Energy label B.
Funding
Components included in cost of construction | Measure additional cost compared with average house (thousand SEK) |
Investment | Total investment 17 279 SEK/residential area + 16,4 % compared to an average house. |
Monitoring equipment | 136 000 SEK |
Thermal Insulation
Conventional. Walls U-value 0,15, roof 0,11. Insulation 120 mm.
Air Tightness
0,8 l/s.sq.m.
Heating and Hot Water
Exhaust air heat pump. hot water preheated with waste water, solar energy and district heating.
Windows and Shading
Triple paned U-value 1,15.
Solar Thermal
132 Sq.m, 28 770 kWh/year.
Electricity Saving Products
Appliances, lightning, fans, pumps, and elevator.
Water Saving
Water efficient appliance. Waste water recycling.
Main Results
- With insulation in Kv Jöns Ols can reduce energy consumption for heating by 28 kWh / usable area in southern Sweden and up to 40 kWh / usable area in northern of Sweden. With insulation in Lindås a passive house additional 12 to 15 kWh / usable area isolated away.
- With an exhaust air heat pump, it is possible to save between 25 and 30 kWh / usable area more nearly independent of the building's location in the country and almost independent of its isolation standard.
- This saves recovery almost as much as insulation measures in Jöns Ols basically wherever located. In southern Sweden, the saving of the recovery of exhaust air heat pump greater than from the supply of recyclable matter insulation standard.
- The further north the house is located, the greater the savings with a starting supply of recycling systems compared with exhaust air heat pump whatever insulation standard.
Lessons learned
- Very heat went the first year to dry construction moisture. The measurements showed that in the first year used 14 kWh / usable area energy more than other years, as the drying of construction moisture required a lot of energy.
- The results show that most single isolation measures are profitable except that only enhance the basement wall insulation, but as one of several measures does not lower the overall profitability so much that it should be excluded. The added value is high when insulated basement walls are becoming hot and dry.
- LCC method shows that with reasonable yield and reasonable energy price increase is the investment of the exhaust air / outdoor air profitable in Kv Jöns Ols. The solar panels are not viable when the solar panels on the roof was expensive because of its design. The advanced system for hot water and distribution measurement of heat is not profitable.
Additional Information
Ms Therese Rydstedt
SABO - The Swedish Association of Municipal Housing Companies
E-mail: therese.rydstedt@sabo.se
Web: www.sabo.se