Remerciez-le!

Remerciez @Admin pour avoir partagé cet document gratuitement, de la manière la plus simple, en partageant sur les réseaux sociaux.

Technical Indoor Climate Guide Draft! 2014-03-13 2 TECHNICAL GUIDE www.swegon.c

Technical Indoor Climate Guide Draft! 2014-03-13 2 TECHNICAL GUIDE www.swegon.com Foreword The aim of this Technical Guide is to serve as a reference work that is useful to both practising engineers and during different training courses. The Technical Guide deals with technical issues related to ventilation, air handling, indoor climate and energy housekeeping, but does not claim to be comprehensive. It is fully possible to build poorly working systems with the best products available on the market. Consequently, it is extremely important to have knowledge of what is required to build well-functioning systems with maximum possible comfort and the lowest possible energy consumption. A client rarely has the necessary skills to assess and predict the consequences of a specific decision. It is therefore the responsibility of the consultant to present the technical and financial consequences of decisions made during a project. The client, of course, does not want to pay more than necessary for a particular action or solu- tion. And here lies a danger — you get what you pay for! Today the most common procure- ment methods focus primarily on the price at the time of procurement. We tend to forget the very purpose of the air handling installation — to provide a good indoor climate that creates ideal conditions for working and residing in the served premises. As there is also always considerable focus on realising as low energy consumption as possible, the likelihood of disregarding the requirement of good indoor climate increases. One condi- tion for being able to achieve a good indoor climate without using excessive energy, is to have an understanding of the complete picture. This Technical Guide aims to provide essential basic information and knowledge about how the relationship appears. Included at the end of the Technical Guide are definitions, designations, conversion factors, formulas, thermal data for air and water as well as further reading tips, publications which in neutral terms describe matters that may be useful to know from a designer, installer or user perspective. Laws, standards and regulations may differ in different countries and it should be noted that this Technical Guide in many cases refers to Swedish standards and regulations. It should also be noted that standards and regulations change with time. A large number of industry experts have contributed with content and have reviewed and proofread the guide, but Swegon assumes no liability or responsibility for any errors. Swegon AB 3 TECHNICAL GUIDE www.swegon.com Content Foreword 2 Purpose of the climate installation 5 Why ventilation?. ........................................................................ 6 Why a good indoor climate?. ...................................................... 7 From requirement to technical solution 9 Indoor climate requirements....................................................... 9 Air quality. .................................................................................10 Room air, air quality...............................................................11 Airflow, air quality. .................................................................12 Air velocity.............................................................................13 Thermal indoor climate..............................................................14 Heat transfer..........................................................................14 Radiation. ...............................................................................15 Convection. ............................................................................16 Evaporation, evaporative release. ............................................16 Temperature. ..........................................................................17 Clothing.................................................................................18 Operative temperature...........................................................19 Airflow, excess heat.............................................................. 20 Sound/Acoustics. .......................................................................21 Energy requirements. ................................................................ 22 The lifecycle of a building......................................................... 23 Demand-controlled ventilation. ................................................. 24 Environment classes. ................................................................. 25 Indoor climate products 27 Chillers and heat pumps........................................................... 28 Air handling units..................................................................... 30 Heat recovery in air handling units........................................ 31 Air diffusers. ............................................................................. 32 Waterborne indoor climate products........................................ 34 Acoustic products. .................................................................... 36 Flow control products. .............................................................. 37 Products for residential ventilation............................................ 38 Indoor climate systems 39 Ventilation principles. ................................................................ 39 Climate systems air/water......................................................... 40 Cooling systems. ....................................................................... 43 Electrically driven compressor cooling. ................................... 44 Free-cooling.......................................................................... 46 District cooling...................................................................... 46 Evaporative cooling............................................................... 47 Sorption cooling. ................................................................... 47 Ventilation systems....................................................................51 Air conduction in premises....................................................... 55 System solutions in different building types 61 Offices, airborne systems. ......................................................... 62 Office, waterborne systems...................................................... 63 Industrial buildings. ................................................................... 64 Commercial buildings............................................................... 65 Public buildings. ........................................................................ 66 Hotels. ...................................................................................... 67 Apartment buildings, central solutions. ..................................... 68 Apartment buildings, central solutions for renovation............... 69 Apartment buildings, decentralised solution............................. 70 Detached and terrace houses. ....................................................71 Project design 73 Project design for a good acoustic environment. ........................74 Noise from fans........................................................................ 77 Sound power level and sound pressure level. ......................... 78 Sound generation in straight ducts. ....................................... 79 Comparisons......................................................................... 80 Sound attenuation. ................................................................... 81 Design tips for sound. ............................................................... 87 Project design for fans.............................................................. 89 System losses fans................................................................. 91 Project design for duct systems. ................................................ 92 Project design for mixing air ventilation.................................... 94 Project design for displacement ventilation............................... 99 Project design for waterborne climate systems. ....................... 104 System design..................................................................... 105 Project design for climate beams..........................................110 Project design for comfort modules. .....................................112 Project design for induction units.........................................113 Guidelines waterborne climate systems................................115 Project design for residential ventilation. ..................................116 Airflows...............................................................................116 Residential energy consumption...........................................117 Residential noise. ..................................................................117 Software utilities for project design.........................................118 Measuring and commissioning 119 Measuring and commissioning. ................................................119 Measuring in ducts. ..............................................................120 Measuring on supply air diffusers.........................................121 Commissioning chilled/climate beams & comfort modules. ...123 Airflows and cooling capacity levels for different activities. ......124 Example of airflow requirement for different premises. ............125 Factual information 127 Terms and definitions. ..............................................................127 Ventilation terminology...........................................................128 Efficiency concepts for air........................................................128 Comfort zones. ........................................................................130 Conversion factors, symbols and units.....................................132 Conversion factors...............................................................132 Symbols and units................................................................135 Heating data. ...........................................................................136 Mollier diagrams. .....................................................................137 Pressure drop diagrams ducts..................................................139 Formulas. .................................................................................143 Worth reading - bibliography. ................................................. 144 4 TECHNICAL GUIDE www.swegon.com 5 TECHNICAL GUIDE www.swegon.com Purpose of the climate installation Ventilation air is utilised for different purposes. Its main task is to remove contaminated air and replace it with clean and tempered air. Contaminated air can refer to impurities in the form of gases and particles, but excess heat can also be regarded as an impurity in some cases. Another important task of ventilation is to create a good indoor climate without draughts and with small tempera- ture differences in the occupied zone. The room climate is composed of a number of factors including air velocity, air temperature and radiation temperature. An imbalance of one or more of these factors in rooms used by people may cause draughts. In order to maintain these basic functions the air handling installation must be designed so that: • it is stable against interference. Interference may be partly external, mainly wind and temperature as well as partly internal interferences, for example, convection currents from various heat sources. Stability against external inter- ference requires, among others, that the installation is designed with a minimum pressure drop. • they are easy to control and measure. The installation must be designed for air terminals with fixed measuring tappings or fixed measuring devices in main and branch ducts. The installation of fixed measuring devices signifi- cantly reduces the time needed for commissioning as well as the overall cost. A fully functional total solution requires collaboration between installation technicians, builders and architects. The ventilation consultant needs to enter the construction pro- cess at an early stage to specify requirements for requisite areas, the consequences of the building design, etc. so that the demands on the indoor climate can be met at the lowest possible cost. Purpose of the climate installation 6 TECHNICAL GUIDE www.swegon.com Purpose of the climate installation Why ventilation? The word ventilation comes from the Latin, ‘ventilare’, which means being exposed to the wind. Today, we have given the word vent a more specific meaning, namely air exchange. We replace used air with clean air. To replace used air with clean air requires energy. New, more stringent energy requirements risk leading to reduced airflow, which in turn can result in a repeat of the mistakes made in the 1970s in Sweden. When a new building code (SBN 75) came into effect in the mid-1970s, airflows were restricted at the same time as demands on the air tightness of buildings were strengthened. The result was what came to be known as “sick buildings” and SBS (“Sick Building Syndrome”). These sick buildings have been shown to have the following negative effects on the health of individuals: • Irritation of eyes, nose and throat • Rhinitis and nasal congestion • Repeated respiratory infections • Headaches • Tiredness • Heavy headedness, concentration difficulties • Nausea and dizziness The cause of “sick buildings” is a complex issue. The follow- ing points represent an attempt to compile the most signifi- cant causes: • An attempt to minimise production costs • Inadequate documentation • Procurement procedures • Built-in moisture in houses • Neglected operation and maintenance • Energy savings through reduced airflow • New and unproven building materials • Inadequate cleaning Lessons What we can learn from history is that demands on energy savings must never be pushed so far that demands on ade- quate airflow are jeopardized. Accordingly, good ventilation is not only important for the indoor climate to be perceived as good, but also central to the health of people. 7 TECHNICAL GUIDE www.swegon.com Purpose of the climate installation Experienced indoor climate An individual’s indoor climate experience is an interaction of several factors that affect our thermal comfort: • Activity level, the body’s heat production • Clothing’s heat resistance • Ambient air temperature • Ambient surface temperature • Relative air velocity • Relative air humidity According to professor P O Fanger an ideal indoor climate is produced when individual experiences thermal comfort, i.e. when a person is thermally neutral. However, one of the problems always faced uploads/Geographie/ indoor-climate-guide.pdf