Air conditioning buildings pdf

The reason for its popularity is that double-glazing has many benefits beyond simple energy efficiency. The energy measures most often adopted during EDAS advice have been those which have benefits additional to simple energy efficiency.

Very often such measures will be adopted even though a simple energy payback calculation may identify them as not being cost effective.

Therefore, designers should be fully aware of these additional advantages of energy efficient technologies to increase the likelihood of them being accepted. There is a tendency among designers to be followers of fashion when adopting energy efficiency, and in particular adopting a centre piece or energy efficient statement, normally a visible feature. Monitoring building energy use has shown that, buildings which focus their energy attention on one particular issue, are often not energy efficient in practice.

Energy flows within air-conditioned buildings are complex and many faceted, see figure 5. All the different forms of energy use in a building must be considered if the overall performance of the building is going to be energy efficient. The introduction of a nationally agreed non-domestic energy-labelling scheme would assist this process and allow clients to take more informed decisions.

Not only do the various energy efficient technologies have to compete for limited funds against inefficient technologies, but also against themselves and renewable energy technologies. Table 5. Sometimes however, the primary aim is to make a visual statement, i. The principles of integrated design, which all designers are aware of, too often seem to be forgotten. Without integrated design the architect can simply design the fabric focusing on the aesthetic and structural properties.

The services engineer can then fix the environmental control in the building! We all know that it should not be like that. Yet this still occurs in many projects, after all it can suit all parties. Architects can get the building to look just how they want to, while the services engineer does not have to get involved in complex debates with the rest of the design team. The services engineer can simply design a system for a building where all the fabric variables have already been fixed, making the whole process less time consuming.

There really is no motivation for the engineer to reduce the capacity of the installed plant when their fees are related to the cost of the plant. The net result can be an air conditioned building which uses far more energy than it need, at the same time as making the system more complex to operate and maintain.

If the occupants cannot afford to maintain or operate such systems adequately, the benefits in improved environmental control are lost. In extreme cases the lack of integration in the design team between the design of the fabric and services can result in the fabric failing. For example, a recently designed award-wining museum has never achieved the level of environmental control required, uses excessive energy and has water condensing on walls and windows.

Meanwhile the occupants think that better environmental control would have been achieved in a medieval building with earth floors. The advantages of an air conditioned building which incorporates the principles of integrated design go beyond simple energy saving. FORM The importance that form has on deciding whether a building is air-conditioned or not is very important and reasonably well understood, see figure 5. The impact that form and fabric can have on the annual energy consumption of air-conditioned buildings is less clear.

Energy efficient designs must be robust enough to cope with the range of conditions that the building will experience over its lifetime. In particular systems designed today should be able to cope with the impacts of climate change and changes in occupant use.

Climate Change Although the evidence for global warming is still controversial, the majority of world climate experts now agree that global warming will occur and there is growing evidence that it is already happening. Given such assumptions it is possible to model how a building will perform. However, many designs are very dependent on occupants using a particular space in a certain way, or controlling various elements of the building and its services in a particular way.

Three examples of this are as follows: 1. Atria and glazed walkways: These are very often designed to be energy efficient features allowing daylight and enhanced ventilation to penetrate a building. During the design the assumption is that the spaces are treated as buffer spaces and so are not actively conditioned i. The reality is often very different. Because such spaces are very often attractive, the tenants want to make use of them all year round in a similar way to other spaces within the building, e.

So what was initially planned as an energy saving feature turns out to be an energy-guzzling feature. Further, had the original design assumed the space was to be fully conditioned it would have probably been designed differently. The use of Venetian blinds. Heavily glazed facades can allow daylight to reduce the need for electric lighting. However they can also result in high solar gains.

Blinds can assist in allowing adequate daylight while reducing solar gains and glare. The assumption often made during the design is that during overcast periods the blinds are pulled up, or at least the slats are in the open position, and that during sunny periods when cooling or shading is required, they are pulled down and their slats are in the closed position.

Buildings which require sophisticated controls, also require sophisticated controllers and in turn these require knowledgeable operators. If the occupants of the building are unlikely to have adequate knowledge, or cannot afford to buy in the necessary expertise, systems should be kept simple.

However, the above areas all require further research, in particular there is a need to test the sensitivity of different design strategies to different assumptions about occupant use in order to assess the robustness of the various options. As a result of such work it is expected that several strategies currently thought of as energy efficient will be found to be inefficient.

In particular, theoretical energy savings do not always materialise; similarly installing more plant does not always result in improved occupant comfort and environmental control. Energy efficient design has now moved beyond the simple theoretical analysis of predicted savings to the adoption of proven techniques, based on the results of monitoring buildings over the last 20 years.

In particular, the importance to detail throughout the design process, and the role of good commissioning, operation and maintenance have been identified. Where appropriate, air conditioning should be incorporated in the design and not treated as an unnecessary evil. Clients should however be warned of the operating and maintenance costs and designers should be realistic as to the environmental benefits that will materialise.

The overall system design should be robust to future climate change and changes in occupant use. Results Citations. Citation Type. Has PDF. Publication Type. More Filters. Using Computational Fluid Dynamics CFD , four different cooling systems used in contemporary office environments are modeled to compare energy consumption and thermal comfort levels.

Incorporating … Expand. View 2 excerpts, cites methods. Design of heat pump-driven liquid desiccant air conditioning systems for residential building. Abstract In this study, two workable designs of a heat-pump-driven liquid desiccant HPLD air-conditioning system were proposed for residential buildings.

Multi-zone HVAC control system design using feedback linearization. Most buildings nowadays are equipped with Heating, Ventilation, and Air-Conditioning HVAC systems dedicated for processing indoor air in terms of different parameters: temperature, humidity, … Expand. Energy saving potential of thermoelectric radiant cooling panels with a dedicated outdoor air system. Energy and Buildings.

Hydronic configurations of hybrid heat production systems in buildings: General design methodology and case studies. Hybrid heat-pump-driven liquid-desiccant system: Experimental performance analysis for residential air-conditioning applications. Applied Thermal Engineering. Abstract A compact heat-pump-driven liquid-desiccant air-conditioning unit for residential buildings is proposed and constructed to validate its energy and air-conditioning performance … Expand.

Hydronic design of cogeneration in collective residential heating systems: state-of-the-art, comparison and improvements. Electric demand minimization of existing district chiller plants with rigid or flexible thermal demand. Abstract Building cooling drives the peak electric demand in summer; therefore, it is an important component in energy related costs.