Forenklet behovsstyrt klimatisering av kontorbygg

The R & D project "Simplified demand controlled air conditioning in office buildings with very low heating demand" is based on the fact that future well-insulated buildings will have a marginal heating demand. This makes simplified systems relevant, and the need for local heating can significantly be covered with the ventilation system. Such simplification was attempted in the '70s. At that time maximum heating demand was 5-10 times greater than is the case with the upcoming building regulations on passive house level. The result was unsatisfactory indoor climate. There is reason to believe that current premises and technical solutions provide significantly better results. Many building owners are interested in simplified systems, but without good documentations few are willing to go all in. The project will develop concepts for ventilation based space heating fit to buildings with very low heating demand, as well as develop documentation on the function and the conditions that must be fulfilled. Documentation will be based on technical measurements and intervention studies with climate surveys conducted in Miljøhuset GK - Norway's first passive office building, supplemented with CFD simulations. In the initial phase of the project, a state-of -the -art report was developed, describing the selected solutions in four pilot projects in the energy sector: The Bellona building, Papirbredden 2, Miljøhuset GK and Sparebank 1 in Trondheim. Furthermore, methods report for intervention studies, field measurement s and CFD simulations was developed. Initial CFD calculations, field measurements and reference study on the indoor environment survey were conducted. The first project period including winter conditions, winter 2013/14 was perhaps the most exciting phase of the project. Different operating strategies and supply air temperature were tested on cold winter days. Intervention studies were carried for the different strategies, and indoor climate survey answered by users of the GK Environmental house. This included GK employees and building tenants. New intervention studies were conducted in winter 2015/15 to verify and hopefully strengthen the findings from the previous winter season. One of the main differences now was measuring of actual supply air temperature and room temperature for each respondent, not only supply air temperature after the air handling unit. Temperatures were logged via the building's BMS. With help of master students, also the effect of individual demand controlled ventilations has been briefly studied. A field laboratory was established in a cellular office at Miljøhuset GK. Ventilation effectiveness, air speed and temperature conditions and draft risk were investigated for different operating strategies. Similar investigations were done using laboratory experiments for more controlled conditions. The results from field measurements have been used further as input for CFD models. There are few days a year at design conditions. To understand the physics of the flow pattern and examine scenarios that are hard to measure, CFD simulations were used. Conditions down to -20?C was examined. The project has documented that in buildings with very low heating demand, short periods (1/2 hour) with up to two degrees of over-temperature can be applied. This is enough even for the coldest days in the Oslo Climate. The results show not only satisfied users, but indicate that women are actually positive to slightly higher supply air temperature. Objective measurements and simulations have shown that the air change efficiency is good, comfort requirements are met and there is low risk for draft problems. With normal window heights downdrafts should not be a problem. It is possible to make use of simplified solutions for climate control in this type of building. This could have major impact for the building industry. We would stress that characteristics of the supply diffuser is important for the result, and this must be documented for each type of diffusor. The report "How to achieve good thermal comfort without separate heating system in buildings with very low heating demand?" presents the main results as well as new recommended specifications texts and advices for design and operation. Preliminary results from the project were published in the international conferences Indoor Air 2014, the 35th AIVC conference, as well as in special seminar under the scientific programs on the Norwegian HVAC days in October 2014. The main results were summarized through short and to-the-point lectures on the project's final seminar /webinar in November 2015. This is filmed and available at the project website http://www.sintef.no/projectweb/for-klima/ . There is great interest in the results. During spring 2016 presentations are given for the industry from north to south in Norway, lectures given at HiOA. A scientific publication of the main results will also be published.

Fremtidens godt isolerte bygningskropper vil ha svært lavt oppvarmingsbehov. Med tilstrekkelig lavt oppvarmingsbehov er det mulig å forenkle dagens klimatiseringsløsninger og oppnå godt inneklima med lavere investerings- og driftskostnad. De bærende idee ne er: 1. Behovet for lokal varme kan dekkes helt eller i betydelig grad med ventilasjonsanlegget, slik at det lokale varmeanlegget kan fjernes eller forenkles. 2. Direkte brukerstyring av klimatiseringsanleggene gir flere fornøyde brukere og lavere energ ibruk. 3. De som først kan utvikle og dokumentere at slike løsninger fungerer godt i næringsbygg, vil bidra til mer bærekraftige bygg, spare byggeiere for både investerings- og driftskostnader og få et markedsmessig fortrinn både nasjonalt og internasjona lt. Prosjektet er delt i fire arbeidspakker: Arbeidspakke 1 Innhente informasjn om eksisterende løsninger og utarbeide en "state of the art"-rapport Arbeidspakke 2 Basert på erfaringer i arbeidspakke 1 gjennomføres CFD-simuleringer for tilluft med ov ertemperatur og varierende luftmengde for å verifisere feltmålinger og utvikle forutsetningene for god funksjon. Det gjennomføres også LCC studier for løsningene. Arbeispakke 3 omfatter utvikling og testing av tekninske løsninger i felt/lab. Det gjennomf øres intervensjonsstdier med case-control grupper. Studiene følges opp med fysiske målinger og loggedata. Arbeidspakke 4 Heve kompetansenivået i byggenæringen gjennom å formidle dokumentert kunnskap om løsninger, forutsetninger