A good HVAC system is the key to maintaining a comfortable, healthy interior environment. Through the years many home owners ask about a technique to cut down on the cost of power and HVAC. They don’t want to sacrifice the interior environmental conditions, however they do want a good plan on how to save money and equipment. The great thing that always happens is that energy bills are reduced substantially and of course the HVAC system capabilities is improved. This is a standard part of any mechanical engineer specializing in energy and HVAC.
Step one to acheiving system optimization is to reduce the load. This step typically involves a long range plan which itemizes the actions to be taken based on best return on your investment. Reducing the system load will allow it to operate more efficiently. If a new system or systems are now being considered, it is going to be more economical to design for a load reduction versus the existing load. A few common load reduction strategies include:
1. Tighten the building shell and add supplemental insulation. Adding insulation in an existing building is probably not do-able for some, so more consideration should be aimed toward the exterior shell, especially doors and windows.
2. Installing energy-efficient windows. This is a big item for some buildings that have single pane windows. The installation of double pane glazed windows with a temperature break is a wonderful return on your investment. Make sure they are ENERGY STAR qualified windows. Tinting or Low-E coatings will even be the best.
3. Changing the lighting system. The average commercial building has a lighting density of 2-3 watts per sq. ft. to maintain a comfortable lighting level. This is a big part of the HVAC load and almost any efforts in this direction will lower the cooling requirement of the building. Vanity lights (ocassionally named architectural lighting) are not always power efficient and must not be considered if you want to reduce energy and HVAC costs. Energy-efficient lights release less heat into air conditioned space than older light bulbs. When you have a return air plenum instead of return air ductwork, consider light troffers so that some heat from the lights is returned to the HVAC system rather than bleeding into the occupied space.
4. Choosing equipment with better efficiency ratings that have the power saver choice will reduce the heat gain in the space. Items to consider include copiers, food processors, personal computers and refrigerators.
5. Control ventilation by having your outside air balanced. Many building owners have blueprints of the original HVAC system installation. Have the drawings examined by using an outside professional to verify your air flow rates conform to the latest code standards. If no sketches are available, your contractor be able to make tips for enhancement.
Addressing these things is your first task to decreasing energy and HVAC overheads.
The second step to achieve energy and HVAC system optimization is understanding it. Your HVAC system is crucial for your interior environment, but it also represents a major factor of your utilities. Even though it is past the information in this article to debate every system, a few recommendations could be answered. Every HVAC system component has grown in efficacy over the years. If your system is older than 13 years old, it is time to begin planning for an upgrade to new equipment. Properly serviced residential systems have a life expectancy of about 15 years give or take, but seem to fail at the most inconvenient times. You should have a plan in place for the day your equipment fails.
Business systems vary, but if your building is using specially designed systems, a similar lifetime can be likely. For industrial or large business systems, the HVAC system may be more advanced and require an individual analysis using a mechanical engineer. As I stated earlier, These types of systems will vary so an individual analysis works for larger systems. What all these systems have in common is they’re often driven by electricity. Electricity has its price, so any attempt in the direction of improved efficiency is a plus.
Energy Savings Ideas:
Find a professional contractor you can trust. If you are a property owner, find the best HVAC contractor or mechanic to evaluate and maintain your system. Assuming you are a large commercial building owner, look for a commercial HVAC contractor for regular maintenance and a trusted contractor for unbiased suggestions. I do advise against using a mechanical engineer who works for the HVAC Company; find a third party contractor for impartial information.
Verify your HVAC system load. Industrial properties have more complex settings related to conformint to code requirements, ventilation rates, etc and therefore are different to each place.
Choose equipment rated for the load. DO NOT OVERSIZE! More-is-better does not apply for HVAC systems. It is going to cost more to purchase the apparatus as well as use it. Get the load and the equipment selection right the first time.
Buy top efficient or Energy Star equipment. Most of the newer systems include variable speed drives for moving parts. Over the years of ownership this is repaid many times over. Evaluate standard efficiency equipment to high efficiency equipment in terms of initial cost and running costs. Any good HVAC company or contractor will know this.
Think about some kind of power recovery for air that is exhausted from the place and re-use it somehow to enhance the incoming air. That is the air you’ve paid for, so using a portion of the energy before exhausting it ought to be top priority.
For large commercial complexes, think about preparing outside air with a dedicated outside air unit. This can solve problems regarding moisture control in many circumstances. It may also increase comfort levels and allow for further equipment optimization.
Large complexes should think about economizers on their equipment. Most current codes require economizers on equipment over 15 tons in size. Often offered at a low incremental cost, these units draw in fresh air from outside whenever the temperatures (or moisture) outdoors is lower than the temperature inside.
Both home owners and small commercial building owners should install programmable thermostats. Large buildings should setup a Direct Digital Control (DDC) system. The investment will pay back more than the cost very quickly.
The third step to achieve system optimization is to control your system.
Programmable Thermostats: A great investment for anyone is a programmable thermostat. These are really easy to use and come with built in strategies based upon time scheduling. Most companies offer seven day programs which can turn the HVAC system on and off to compliment and temperature. This is a wonderful way to ensure the system is on only when needed.
DDC Systems: For the large commercial building, I consider this as a must have system. Installation costs are lower now and performance is better. They are often incorporated into any system and expanded as needed. Some of the more accepted elements of these systems are enhanced start/stop, multiple zone controls, temperature sensor and fresh air control. A key benefit of these systems is their capability to be scaled up to the largest of commercial applications. This implies you can install a somethng simple at first then increase the controls later to include everything. Again, the payback is quick and well worth the investment.
Coil Cleaning: This is always a big item overlooked by almost everyone. Condenser coils tend to collect dust and debris because they are outdoors. Diry coils make the compressor work overtime and results in a higher refrigerant temperature in your refrigeration system. Dirty evaporation and heating coils circulate the dust and fibers inside the building. Clean them a minimum of once a year
Operation and Maintenance
The fourth and last step to realize better system operation is consistent up keep. The most efficient systems are always managed. You can ensure reliability, efficiency and a longevity for any HVAC system by using these suggestions.
Find a professional company you can trust. Find a good company or technician to analyze and take care of your system. If you are a large business owner, find a commercial|an industrial} HVAC company for normal upkeep. Ensure you record and document servicing with when they vist and what they did each time.
Home owners must always get a seasonal tune up. The operation of your system will vary with the seasons of the year.
Change your air filters regularly. Don’t use anything less than a MERV 5 filter to make sure most of the dust is captured. Clean filters will save fan energy.
Energy and HVAC optimization will help to lower energy fees. A little time getting to know your system and familiarizing yourself with money saving strategies typically associated with regular HVAC service will reduce your costs and increase the life span of your system.