Determining the optimal terminal box airflow is a complex process which is influenced by various factors, such as weather condition, supply air temperature, primary air fraction and internal load. A guideline for determination of a cost efficient minimum airflow setpoint for VAV terminal box units is drawn in this research. The most efficient optimal minimum airflow setpoint should not be a fix setting, but should be changing with zone load and ventilation requirement. A fixed minimum airflow is used in conventional control strategies. The terminal box minimum airflow required is not a constant since the supply air temperature, fresh air fraction and zone load are different. It is important to set up the minimum airflow to ensure IAQ and thermal comfort and to minimize energy consumption. Analysis has been carried out to compare how the supply air temperature, fresh air fraction and zone load affect the minimum airflow setting of an exterior zone. And 30% of design airflow is not always a good number, and may cause comfort issue or ventilation problem. If the minimum airflow is set higher than required, terminal boxes will have significantly simultaneous heating and cooling, and consume more fan power in the AHUs. If the minimum airflow is set lower than required, indoor air quality (IAQ) will be a concern. Energy saving ratio study is conducted to estimate the energy saving benefit by implementing an optimized minimum airflow.

Indiana University-Purdue University Indianapolis (IUPUI) / Air handling unit systems are the series of mechanical systems that regulate and circulate the air through the ducts inside the buildings. In a commercial setting, air handling units accounted for more than 50% of the total energy cost of the building in 2013. To make the system more energy efficient and reduce amount of CO₂ gases and energy waste, it is very important for building energy management systems to have an accurate model to help predict and optimize the energy usage and eliminate the energy waste. In this work, two models are described to focus on the energy usage for heating/cooling coils as well as fans for the air handling unit. Enthalpy based effectiveness and Dry Wet coil methods were identified and compared for the system performance. Two different types of control systems were modeled for this research, and the results are shown based on occupancy reflected by the collected CO₂ data. Discrete On/O and fuzzy logic controller techniques were simulated using Simulink MATLAB software and compared based on energy reduction and system performance. Air handling unit located in the basement of one campus building is used for the test case of this study. The data for model inputs is collected wirelessly from the building using fully function device (FFD) and pan coordinator to send/receive the data wirelessly. The air handling unit modeling also is done using Engineering Equation Solver EES Software for the coils and AHU subsystems. Current building management system Metasys software was used to get additional data as model inputs. Moving Average technique was utilized to make the model results more readable and less noisy. Simulation results show that in humid regions where there is more than 45% of relative humidity, the dry wet coil method is the effective way to provide more accurate details of the heat transfer and energy usage of the air handling unit comparing to the other method enthalpy-based effectiveness. Also, fuzzy logic controller results show that 62% of the current return fan energy can be reduced weekly using this method without sacrificing the occupant comfort level comparing to the ON/OFF method. Air quality can be optimized inside the building using fuzzy logic controller. At the same time, system performance can be increased by taking the appropriate steps to prevent the loss of static pressure in the ducts. The implementation of the method developed in this study will improve the energy efficiency of the AHU.

Commissioning of HVAC systems has potential for significant improvements in occupant satisfaction, comfort and energy consumption, but is very labour-intensive and expensive as practiced at this time. Previous investigators have capitalized on digital control systems' capability of logging and storing data and of interfacing with external computers for open loop control by developing methods of automated fault detection and diagnosis during normal operation. Some investigators have also considered the application of this technique in commissioning. This thesis investigates the possibility of utilizing first principles and empirical models of air-handling unit components to represent correct operation of the unit during commissioning. The models have parameters whose values can be determined from engineering design intent information contained in the construction drawings and other data available at commissioning time. Quasi-dynamic models are developed and tested. The models are tested against design intent information and also against data from a real system operating without known faults. The results show the models agree well with the measured data except for some false positive indications, particularly in the damper and fan models, during transients. A procedure for estimating uncertainty in the instrumentation and the models is developed. The models are also tested against artificial faults and are able to detect all of the faults. Methods of diagnosing the faults are discussed.

The goal of this diploma thesis is to design a modular air handling unit based on determined requirements. Modular air handling units provide great flexibility for consultants when work-ing on a project. Modular air handling units are assembled using many sections (heater section, cooler section, humidification section, fan section, etc) which gives the consultant an advantage to use only those sections necessary for particular project.

This diploma thesis deals with the creation of visualization for testing lab for air conditioning unit. This unit was made by Strojírenský zkušební ústav. The visualization was programmed in the visualization and simulation program called ControlWeb. This application allows controlling, monitoring, storing and retrieving all necessary variables. Next part of diploma thesis discusses techniques of measurement, automation devices and visualization software.

<div>The United States Environmental Protection Agency (EPA) is charged with pro-tecting human health and the environment. Part of this mission involves regulating heavy-duty trucks that produce particulate matter (PM), unburned hydrocarbons (UHC), carbon dioxide (CO2), and nitrogen oxides (NOx). A byproduct of lean burn combustion in diesel engines is NOx. NOx output limits from commercial vehicles have been reduced significantly from 10 g/hp-hr in 1979 to 0.2 g/hp-hr in 2010. Ad-ditional reductions are expected in the near future.</div><div><br></div><div>One pathway to meet future NOx emissions regulations in a fuel efficient manner is with higher performing exhaust aftertreatment systems through improved engine air handling. As exhaust aftertreatment’s capability to convert harmful NOx into harmless N2 and H2O is a function of temperature, a key performance factor is how quickly does the exhaust aftertreatment system heat up (warm-up), and how well does the system stay at elevated temperatures (stay-warm).</div><div><br></div><div>When the warm-up strategy of iEGR was implemented over the heavy duty federal test procedure (HD-FTP) drive-cycle, it was able to get the SCR above the critical 250◦C peak NOx conversion threshold 100 seconds earlier than the TM baseline. While iEGR consumed 2.1% more fuel than the TM baseline, it reduced predicted tailpipe NOx by 7.9%.</div><div><br></div><div>CDA implemented as a stay-warm strategy over the idle portions of the HD-FTP successfully kept the SCR above the 250◦C threshold for as long as the TM baseline and consumed 3.0% less fuel. Implementing CDA both at idle and from 0 to 3 bar BMEP consumed an additional 0.4% less fuel, for a total fuel consumption reduction of 3.4%.</div><div><br></div><div>A method to predict and avoid compressor surge (which can destroy turbochargers and in fact did so during the HD-FTP experiments) instigated by CDA was devel-oped, as discussed later, and implemented with staged cylinder deactivation to avoid compressor surge.</div><div><br></div><div>The literature does not consider the fidelity of road grade data required to ad-equately predict vehicle fuel consumption and operational behavior. This work ad-dresses this issue for Class 8 trucks by comparing predicted fuel consumption and operation (shifting, engine torque/speed, and braking) of a single Class 8 truck simu-lated with grade data for the same corridor from different sources. The truth baseline road grade (best fidelity available with LiDAR) was obtained previously. This work compares road grade data to the truth baseline from four other typical methods i) utilizing GPS to record horizontal position and vertical elevation, ii) logging the pitch of a cost effective, commercially available IMU, iii) integrating the horizontal and ver-tical velocities of the same IMU, and iv) a commercially available dataset (Comm). Comm grade data (R2=0.992) best matches the LiDAR reference over a 5,432 m stretch of US 231 where high quality LiDAR data was available, followed in quality by the integrated IMU velocity road grade (R2=0.979). Limitations of the Comm dataset are shown, namely missing road grade (decreased point density) for up to 1 km spans on other sections of US 231, as well as for Interstate 69. Vehicle simulations show that both the Comm data (where available and accurate) and integrated IMU road grade data result in fuel consumption predictions within 2.5% of those simulated with the truth reference grade data.</div><div><br></div><div>The simulation framework described in Chapter 6 combines high fidelity vehicle and powertrain models (from Chapter 5) with a novel production-intent platooning controller. This controller commands propulsive engine torque, engine-braking, or friction-braking to a rear vehicle in a two-truck platoon to maintain a desired following distance. Additional unique features of the framework include high fidelity road grade and traffic speed data. A comparison to published experimental platooning results is performed through simulation with the platooning trucks traveling at a constant 28.6 m/s (64 MPH) on flat ground and separated by 11 m (36 ft). Simulations of platooning trucks separated by a 16.7 m (54.8 ft) gap are also performed in steady-state operation, at different speeds and on different grades (flat, uphill, and downhill), to demonstrate how platooning affects fuel consumption and torque demand (propulsive and braking) as speed and grade are varied. For instance, while platooning trucks with the same 16.7 m gap at 28.6 m/s save the same absolute quantity of fuel on a 1% grade as on flat ground (1.00 per-mile, normalized), the trucks consume more fuel overall as grade increases, such that relative savings for the platoon average decrease from 6.90% to 4.94% for flat vs. 1% grade, respectively. Furthermore, both absolute and relative fuel savings improve during platooning as speed increases, due to increase in aerodynamic drag force with speed. There are no fuel savings during the downhill operation, regardless of speed, as the trucks are engine braking to maintain reasonable speeds and thus not consuming fuel. Results for a two-truck platoon are also shown for moderately graded I-74 in Indiana, using traffic speed from INDOT for a typical Friday at 5PM. A 16.7 m (54.8 ft) gap two-truck platoon decreases fuel consumption by 6.18% over the baseline without degradation in trip time (average speed of 28.3 m/s (63.3 MPH)). The same platooning trucks operating on aggressively graded I-69 in Indiana shows a lower platoon-average 3.71% fuel savings over baseline at a slower average speed of 24.5 m/s (54.8 MPH). The impact of speed variation over, and grade difference between, these realistic routes (I-74 & I-69) on two-truck platooning is described in detail.<br></div><div><br></div>

The main aim of the Master project is a design of the guesthouse with wellness, which has nearly zero-energy consumption and is located in Velká Bíteš. For design is used ARCHICAD, for numeric is used DEKSOFT. This Master project consists of three parts. The first part focuses on the design of the guesthouse, the second part concentrates on a technical design and the third part focuses on the draft of different energy sources, its comparison and evaluation. Guesthouse is a three-story building with walkable flat roof. Wellness, cold rooms and massages are located in the basement. Other places of floor consist of sanitary facilities, technical rooms and common rooms. There are also guest rooms on the other floors and a conference hall on the third room. This final draft has much more positive outcomes than other alternatives; with respect to primary energy and impact on the environment. However, the final draft has higher purchase costs and its financial and operational economy is extremely dependent on the prices of electric power.

Diploma thesis is focused on problematics of ventilation of swimming pool halls. Thesis describes the design of air handling units for swimming pool halls and operation risks. It presents different variants of ventilation with mentioned advantages and disadvantages of individual technical solutions. A swimming pool air handling unit was measured in real conditions as a part of experimental solution. The goal of measuring was to analyze thermal efficiency of cross flow heat exchanger aswell as to monitor working modes and functions of unit. Based on informations gathered during experimental measuring, two different variants of ventilation were designed. Both designs are evaluated economically during extreme weather conditions and during the whole year.

Nästan alla forskningar om klimatförändringar påpekar att de accelererande klimatförändringarna vi ser till stor del orsakas av mänskliga verksamheter. Om vi inte reducerar energianvändningen kommer våra utsläpp av växthusgaser öka kraftigt och det kan leda till en katastrof i framtiden. För att vi ska klara morgondagen måste vi omedelbart börja begränsa vår energiförbrukning. I Sverige har regeringen som mål att minska energiförbrukningen med cirka 20 % från 1995 till 2020 och 50 % till 2050. Nästan 40 % av all energianvändning förekommer i byggnads- och fastighetssektorn.  För att minska energianvändningen i den sektorn måste vi energieffektivisera även våra befintliga byggnader.  En stor del av energianvändningen går till att täcka transmissionsförluster genom väggar, fönster och köldbryggor. Genom att välja fönster med låg värmeöverföring och rätt isolering till byggnader samt minska transmissionsförlusterna i ventilation och uppvärmning skulle mycket energi kunna sparas. Har en byggnad låg transmissionsförlust reduceras energibehovet markant.  Genom att installera ventilationssystem med en värmeåtervinning (FTX) kan energiförbrukningen avseende förvärmd ventilation minskas kraftigt. Ventilation med värmeåtervinning gör det möjligt att återvinna energi från den utgående luften från lokalerna till den kalla uteluften som ska till lokalerna för att uppehålla en god inomhusmiljö, värmeväxlare har verkningsgrad upp till 0,85. För att energiförbättra gamla byggnader till energieffektiva, krävs nya installationer och ombyggnader för att anpassa till miljövänliga byggnader. Det kan ibland vara svårt att installera FTX-system i befintliga byggnader eftersom luftbehandlingsaggregat kräver stor plats. Den ekonomiska avskrivningstiden är lång. I det här examenarbetet kommer ventilations- och uppvärmningssystem att utredas; fokus ligger på installationsteknik samt energieffektivisering beroende på hur lokalen ska användas. Målet är att undersöka hur stort energibehov en byggnad har samt ge förslag till vilket ventilationssystem som passar byggnaden. Med hjälp av ritningar över Lokverkstaden och diverse information om lokalen skapades en modell i simuleringsprogrammet IDA ICE, en av de bästa simuleringsprogramvaror för energibehov i byggnader. När man hade fått fram en modell att jobba med började inmatningar och utfördes förändringar på byggnaden som motsvarar (med hjälp av) det indata man hade fått från beställaren. Ventilationsritningar utfördes i Magi Cad och en luftbehandling har dimensionerats på Swegons hemsida. Temperaturen i lokalen påverkas av olika faktorer såsom dålig isolering m.m. Lokalerna står i dag helt kalla men lokal uppvärmning förekommer vid extrem kyla för att hålla en del VVS så varmt att det inte fryser. Lokalerna har en stor fuktbelastning och en del av golvet består av en mycket tjock betongplatta. Resultatet visar att det bästa ventilationsaggregat som behövs för att klara av luftflödet på 11,6 m3/s, bör ha specifika fläkteffekten på 2,39 kW/(m3/s). Byggnadens energiförbrukning blev 610624 kWh om året i simuleringen. / Almost all research about climate change points to that the accelerating climate changes we see today, is to a large part caused by human activity. If we don’t reduce our energy usage, our emissions of greenhouse gases will increase heavily - which can lead to disasters in the future. To be able to solve potential problems and avoid disasters in the future, we have to start decreasing our energy usage immediately. In Sweden, the government has the goal of decreasing energy usage with about 20 % from 1995 to 2020, and 50% by 2050. Almost 40% of all energy usage is from the construction and property sector. However, to decrease energy usage within that sector we have to make current buildings more energy efficient. A major part of energy usage in the constructions sector goes to cover transmission losses through walls, windows, and thermal bridges.  So, by choosing windows with low heat transfer and the correct isolation for the specific buildings, as well as, decreasing transmission losses through ventilation and heating would result in that a lot of energy can be saved. If a building has a low transmissions lose, the demand of energy would decrease remarkably. By installing ventilations systems with the function of heat recovery (FTX) so could the energy usage regarding preheated ventilation decrease heavily. While, the ventilation and heat recovery makes it possible to reuse energy from the outgoing air from the facilities to the cold air outside that shall be used in the facilities to maintain a good indoor environment; heat exchangers have an efficiency level of 0.85. To make old buildings energy efficient, it requires new installations and remodeling to adjust them to become environment friendly buildings. It can sometimes be hard to install FTX-systems in current buildings since air-handling units requires a lot of space, and that the financial write-off periods can be long. This thesis will investigate the ventilations- and preheating systems with a focus in installation technics and energy efficiency depending on how the facility will be used. The goals are to investigate how large the demand for energy is in a building, as well as, give suggestions to which ventilations systems that would fit best with the prospective building.   With drawings of a locomotive workshop and miscellaneous information about the facility, and a model of the facility by the simulation program IDA ICE the energy demand in the building was simulated. When a model had been created the work with inputs and changes were made on the buildings - with help from input that has been receive from the client. Drawings of the ventilation were performed in Magi Cad and an air handling has been dimensioned on Swegon’s website. The temperature in the facility is affected by several factors, such as poor isolation etc. The facilities are not heated today besides through local heating at extreme low temperature to maintain a sufficient heat to not freeze the HVAC. The facilities have high moisture level, and at the same time some parts of the floor are made of very thick concrete plates. The results of the tests show that the best ventilation unit that is needed to manage the air flow of 11.6 (m3/s) should have the specific fan power of 2. 39 kW/ (m3/s). The buildings energy use became 610624 kWh/year in the simulation. / <p>Vi redovisade i september 2015 men blev hel godkänd nyligen. Jag visst inte om jag vilket år som gäller(2015 eller 2016)</p>

To be able to handle tomorrows need for limited energy consumption we need to reduce our use of energy. The building sector stands for around 40 % of all energy consumption in the society. The government has put up a goal to reduce the energy consumption in our buildings with 20 % by year 2020 and 50 % by year 2050 compared with year 1995. To be able to do reach that goal we need a more energy efficient building stock. The main part of the energy used in our buildings is used for space heating. By installing ventilation systems with heat recovery on the exhaust air it is possible to use the heat-energy in the exhaust air to warm up the incoming air. This can contribute to a reduction in energy use. A ventilation system with heat recovery on the exhaust air is space demanding and there can be problems with finding enough space to do the installation indoors. Therefore it can be an advantage to place the aggregate and the ducts on the outside of the buildings climate shell. A placement exterior of the buildings climate shell or in an unheated space leads to thermal heat losses. The aim with this essay is to investigate how significant the heat losses are on exterior placed ventilation systems. The investigation has been done with help of theoretical calculations and measurements of the temperature difference in the ventilation ducts. Analysis has been made on life cycle costs on how to reduce the heat losses in an economic manner. To buildings, Höstvägen 14 and 22 in Växjö, which have been equipped with exterior placed ventilation systems have been studied. The two buildings have two different types of installation of the ducts. Our result shows that the heat losses through the ventilation systems on Höstvägen 14 and 22 are significant. The majority of the losses occur in the ducts. In the aggregate the thermal bridges in the framework accounts for the larger part.