Energy efficiency measures reduce the long-term ownership cost of a building, in exchange for an upfront investment. However, it is possible to go wrong with energy efficiency, especially when upgrades are deployed without a proper energy audit. This article describes some common mistakes and how to avoid them.
Although energy codes establish a minimum performance level for buildings, these normally apply only for renovations and new constructions. When a specific energy efficiency measure is retroactive for existing buildings, it is made clear through legislation. For example, Local Law 88 in NYC makes lighting upgrades mandatory for all buildings it covers, and the deadline is 2025.
If you are in New York, the State Energy Conservation Construction Code provides the minimum energy efficiency requirements, and New York City has a dedicated NYC Energy Conservation Code. In New Jersey, on the other hand, the requirements are established by the NJ Energy Subcode, which is part of the Uniform Construction Code.
Identify the best energy efficiency upgrades for your building.
Error 1: Not Prioritizing Energy Efficiency Measures
For a given building, not all energy efficiency measures will yield the same return for each dollar invested. As a property manager you should prioritize the upgrades with the best financial performance, since savings become available in a short time. Of course, first you must know which building upgrades are the most promising.
The effectiveness of an energy efficiency measure not only depends on the final performance achieved after the upgrade. You must also consider the existing condition, and analyze the proposed measures based on comparison.
For example, upgrading from incandescent bulbs to the latest generation of LED lamps can achieve massive savings.
On the other hand, only marginal savings are achieved when upgrading from efficient fluorescent lighting, such as T5.
Although LED lighting is proposed in both cases, financial performance is much better in the first example due to the wide gap in efficiency. Think about purchasing a new car with a fuel efficiency of 40 miles per gallon: the owner of a 20 MPG car will achieve higher savings than the owner of a 30 MPG car.
Error 2: Using Generic Savings Values and “Rules of Thumb”
Suppliers of energy-saving equipment often provide generic savings data. In can be represented in many ways, such as:
kWh per year
Dollars per year
These savings values are based on generic case studies, but don’t assume you will get the same result in your building. The existing conditions in your property may be very different than those considered by equipment suppliers.
For example, if you see an air conditioning system that offers 60% energy savings, check the baseline scenario assumed by the provider.
If they assumed a SEER 10 mini-split unit and you have window-type air conditioners, you will achieve even higher savings.
The opposite can also happen: if your AC units are already above SEER 10, you will save less than 60%.
“Rule of thumb” calculations should also be avoided in the design phase. Even if you use energy-efficient technology, optimal performance is not achieved when equipment capacity does not match the load.
Error 3: Overlooking Energy Codes
Energy codes do not mandate energy efficiency measures in old buildings, unless you carry out an addition or major renovation. However, once you choose to deploy energy efficiency, the energy code provides the minimal value you can aim for. In other words, you cannot set a performance target below the code, even if it represents an improvement beyond the existing condition.
You may want to prioritize energy efficiency for certain building systems during a mayor renovation, but there is something you cannot do: ignoring other areas that are also subject to the energy code. In other words, having top efficiency in some building systems does not compensate falling below code requirements with other systems.
After identifying the best energy efficiency measures for your building, you must ensure the proposed upgrades are designed correctly. A poorly-specified upgrade will not yield the expected results, even if the energy audit was carried out by qualified engineering professionals. Remember there is also a permitting procedure, like in any building upgrade project.