The idea that more is better does not always apply to engineering. For example, maximizing energy savings is always beneficial because it reduces the building's operating costs; on the other hand, oversizing mechanical equipment does not bring any benefit. In fact, many construction systems suffer from performance problems both when undersized and oversized, and the best result is achieved when the installed capacity matches the requirements as closely as possible.
This article will describe the negative consequences of oversizing construction systems, which include financial and technical issues. MEP engineering company is the best way to avoid them.
Oversized equipment is more expensive to buy
This is the first negative consequence that most New York building owners face when their mechanical, electrical or plumbing systems are oversized: they drain more capital than necessary. Consider that capital also has an opportunity cost, since any funds used to pay the additional cost of an over-engineered system are funds that cannot be invested elsewhere.
Over-engineering is a common consequence of “rule of thumb” decisions during the design process. These decisions are tempting because they speed up the design and reduce its cost, but any savings are offset by the extra capital spent during installation! The best solution is to work with a design company that takes the time to calculate key building requirements such as lighting levels, space heating, space cooling and water heating. Then the results of this analysis are used to specify equipment of corresponding capacity.
Also consider that an oversized construction system can increase the cost of other installations. For example, if a building has a larger-than-necessary refrigeration installation, the electrical installation that supplies it with energy must also have conductors, protection devices and transformers of greater capacity.
Oversized equipment is also more expensive to operate
The extra costs associated with over-engineering do not end during construction. These systems also require greater energy consumption throughout their useful life: oversized lighting installations consume more electricity, while oversized boilers and furnaces require more fuel. While there are technologies that reduce the output of building systems, such as dimmers for lighting and variable speed drives for motors, the system should have been specified smaller in the first place if you need to operate it below rated capacity all the time.
If the equipment in your facility is oversized and old, you have an excellent chance of reducing operating expenses with a building upgrade. A newer, better-designed facility may have lower capacity and higher efficiency. Even greater savings can be achieved if complemented with automatic controls to optimize operation.
Consider that Local Law 88 of 2009 requires all buildings under its coverage to upgrade their lighting installations by 2025, bringing them to the performance level required by the New York Energy Conservation Code, at a minimum. An engineering consulting firm can evaluate your lighting installations and identify the best upgrades.
Over-engineering makes maintenance more demanding
This mainly applies to HVAC installations. Basically, an oversized unit operates on shorter cycles, increasing the rate of wear on mechanical components. This means that repairs and part replacements become more frequent. Also consider that larger equipment uses larger parts, which are also more expensive.
Oversized equipment is also associated with more noise and vibration . Noise can be distracting and vibration can propagate through some building elements, leading to maintenance problems even in building systems not related to over-engineered installation.
Lighting systems that produce more lumens than necessary are not more demanding in terms of maintenance. However, consider that office lighting is often built into dropped ceilings and these can vibrate a lot when nearby mechanical equipment is oversized. As a consequence, excessively designed mechanical components can damage lighting with propagated vibration.
It is important to note that vibration can be a problem even with adequately sized equipment, but the magnitude is less severe. Additionally, by using suitable spring supports or damping pads, vibration problems can be mitigated or eliminated.
Over-engineering causes discomfort and indoor air quality problems
Humans feel best when the ambient temperature is constant and relative humidity is maintained between 30% and 60%. Extremes in temperature and humidity can cause discomfort and health problems, and overly designed HVAC systems have little control over these variables.
- An oversized air conditioner leads to an excessively low temperature. Furthermore, because it operates on shorter cycles, it does not remove moisture effectively. When you enter an indoor space that feels cold and damp like a refrigerator, one likely cause is an over-engineered room cooling system.
- As you would expect, an oversized space heating system can create a hot, dry environment. In addition to the discomfort it causes, it can irritate the skin, eyes and respiratory system. Low humidity also makes dust and viruses spread through the air more easily, which can lead to allergies and other health problems.
Over-engineering can harm a building's public image
Larger building systems are more expensive and consider that Local Law 84 of 2009 requires properties above a certain size to compare their energy and water consumption and report them annually. From 2020 onwards, this information will be used to assign an energy efficiency rating to buildings, with public disclosure of the rating received being mandatory.
If your building has over-engineered facilities and is also covered by LL84, you may encounter an unfavorable energy grade. Property developers should be especially aware of this, as a low rating is likely to turn off potential tenants – they will associate a low rating with higher energy costs.
Make sure your building systems have the right capacity.
Final Recommendations
“More is better” does not apply in the case of over-engineered buildings. These are more expensive to own and operate, although they are more demanding in terms of maintenance. Oversized HVAC systems are detrimental to air quality, while excessive lighting can lead to mandatory upgrades to comply with Local Law 88. Finally, consider the consequences of going low energy in 2020.
Consulting is the first step to achieving energy efficiency . By performing an energy audit of your building, you can prioritize the best upgrades available. Energy efficiency measures are among the best building upgrades available in New York, considering the high price of electricity and fuel.
