In any MEP engineering project, Mechanical equipment plays a fundamental role in residential, commercial and industrial locations, performing functions such as:
- Cooling and heating space
- Supply of cold or hot water
- Refrigeration
- Ventilation
- Indoor humidity control
These types of equipment and their associated ducts and piping are notorious for their high space requirements but there are several ways to make mechanical installations more compact .
1) Install boilers as close to the roof as possible
Boilers that operate with the combustion of fuels such as oil, propane, natural gas , biomass or biodiesel require a chimney to exhaust the combustion gases. As the chimney must run the entire distance from the boiler to the roof, your space requirements increase as the boiler is located further from the highest level – there are more floors to cover.
Installing a boiler in the highest possible location in a building shortens the chimney, which offers three significant advantages:
- The space that the chimney would occupy on each floor is freed up for other purposes.
- The installation becomes safer, as the risk of combustion gases being released inside is minimized.
- The cost of the chimney is reduced.
An alternative to installing boilers in the attic or upper floor of a building is to simply use a heating technology that does not require a chimney, such as an electric resistance heater or a heat pump. A solar water heater is also a viable option: it is located on the roof, saving internal space, and works with sunlight, free energy input.
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2) Installation of air conditioning units on ceilings
The largest single component of an air conditioning system is typically the condenser , which is typically located outdoors. When installed on the external walls of a house or building, condensers take up a lot of space and can even represent an obstacle to external circulation if located on the first floor.
Condensers also release a lot of heat and the circulation of hot air can be restricted when outdoor spaces are restricted due to proximity to another building or wall. This has two negative consequences: hot air can make outdoor locations uncomfortable and it reduces the operating efficiency of the condensers. On the other hand, if a condenser is located on a roof, hot air can circulate more freely and noise becomes less of an issue.
In large commercial or industrial installations, the equipment used by air conditioning and refrigeration systems is much larger, but the same logic applies – installing these units on roofs saves considerable outdoor space. However, this is only viable if the structure is strong enough to support the weight. Examples of equipment that may be found outdoors in typical commercial or industrial MEP engineering project environments include:
- Compact rooftop air conditioning units
- Air-cooled chillers
- Cooling towers for industrial processes or for water-cooled cooling plants
3) Using the same system for cooling and heating
A heat pump works with the refrigeration cycle, the same physical principle on which air conditioners are based, with the difference that it works in reverse – it extracts heat from the cooler outdoor environment and uses it to heat spaces or spaces. water. Additionally, some heat pumps are reversible, allowing them to consolidate heating and cooling into a single piece of equipment.
Upgrading to a heat pump can also result in improvements in energy efficiency . There are two important pieces of information to note when comparing heat pump models:
- The Seasonal Energy Efficiency Index (SEER) is the ratio of cooling output to energy input during the cooling season.
- Heating Seasonal Performance Factor (HSPF) is basically the same concept, but for when the heat pump is running in heating mode.
SEER and HSPF are indices that relate BTUs (British Thermal Units) and watt-hours, and a higher value translates into reduced energy consumption: it means the unit needs less energy to meet a specific cooling load or heating. For example, an air conditioner with a SEER of 20 will only consume half the energy of a SEER 10 unit, assuming they both have the same cooling output.
Alternatively, unit efficiency can be reported as a Coefficient of Performance, which is also a ratio of cooling or heating output to power input, but using watts for all quantities. Heat pumps typically have a COP of 2.5 or more, meaning they generate significant savings over replacing resistance heaters, which have a COP of 1.
In MEP engineering, an ideal scenario for upgrading to a heat pump would be if a home uses a resistance heater and an older air conditioning unit. In this case, a heat pump would consolidate two devices into one, while improving energy efficiency in both operating modes.
For industrial applications, using an absorption chiller is a viable option to consolidate heating and cooling systems. This type of chiller can use waste heat from a steam plant or industrial process and provide cold water for room and process cooling. It is important to note, however, that absorption chillers are only viable when there is sufficient waste heat; otherwise, a normal compression-based chiller is a better choice.
4) Installation of mechanical equipment in spaces not normally used
Another viable strategy for minimizing usable internal space in your next MEP engineering project, which typically involves mechanical equipment, is to install these units in a location that is not normally used. An example of such locations is:
- Roof bulkheads – This is a type of structure found on many buildings and rarely used. Their main purpose is to provide access to the roof and they tend to be used more during construction and maintenance than during the actual operation of the building.
5) Using mini-split systems instead of packaged rooftop units for small buildings
Packed rooftop units allow multiple condensers to be consolidated as a single unit, but they require considerable duct space . In small residential and commercial locations, mini-split systems are often the superior choice, offering simpler installation and superior energy efficiency. Packaged rooftop units typically go up to SEER 15, while mini-split systems are available with efficiency ratings of SEER 25 or above.
Mini-split systems are a practical option in commercial locations divided into several zones with independent opening hours, such as open-air shopping malls. As sites become larger, rooftop units are emerging as the preferred choice – too many compressors and evaporators would be needed to provide air conditioning with mini-split units.
6) Vertical alignment of equipment on multiple floors
Multi-story buildings typically have components that are repeated floor by floor, and mechanical equipment is no exception. For example, air conditioning systems in high-rise buildings often use a central refrigeration plant to cool water, which is then supplied to air handling units (AHU) that cool the air on each floor.
If AHUs and similar units are aligned vertically floor by floor, it is possible to distribute cold water to all of them with a single pipe running vertically through the building. Because the ducts are installed above the false ceiling, most mechanical equipment will be out of sight.
Associated electrical installations that supply power to mechanical equipment also become more compact when similar units are aligned vertically or horizontally. Multiple circuits can be installed in a single run of conduit, and it is also possible to use a bus duct for equipment that draws high current.
7) Hiring Qualified Professionals for the Design Stage
A well-organized mechanical installation takes up less space and ensuring that the layout is as simple as possible is a process that starts from the project design phase. If mechanical, electrical and plumbing (MEP) installations are designed together, the associated equipment and components can be specified and located with the following objectives in mind:
- Minimizing space and material requirements.
- Avoiding clutter caused by components of different building systems.
There are now software packages that allow you to create and visualize 3D MEP models before beginning the construction process — including Revit , which we use at New York Engineers. These models are a great help in planning how mechanical installations will be laid out in your next MEP engineering project and are also very useful for contractors during material removal and construction.
Conclusions
Optimizing the space used by mechanical equipment in your MEP engineering projects offers several advantages beyond comfort. It may be possible to reduce the cost of installations and, in many cases, also increase energy efficiency. The best way to ensure that a mechanical installation provides optimal performance and an ideal layout is to hire qualified designers and contractors for the project.
Do you have any tips for minimizing mechanical space? Comment below to share your space-saving tips and download our free e-book, “The 5 Most Engineered Building Components” to learn which systems prevent over-engineering so you can avoid unnecessary expenses.
