On average approximately 50% if utility bills are dedicated to HVAC units In the case of commercial properties this is 39% These figures can be greatly reduced If the existing HVAC unit is upgraded to a newer more energy efficient unit.
What makes HVAC units energy efficient?
There are various models of HVAC unit available There are also various types of HVAC unit to choose from The best way to identify how energy officiant HVAC units are Is by looking at it’s efficiency star rating.
Ratings to look for
In the US, The Department for Energy governs all manufactured cooling and heating systems All systems are awarding the AFUE efficiency rating or the Fuel Utilization Efficiency ratio This rating system works on an equation of The percentage of heat produced To every dollar consumed in energy This system is similar to the miles per gallon ratio used with cars The higher a furnace rates The lower it’s fuel consumption.
The Energy Star
The energy star is the EPA voluntary program that defines energy efficiency across HVAC models This is less of a verification But more of a certification. If a HVAC unit has the energy star mark It means the unit has been tested and approved by the EPA This certification means the HVAC unit is “Energy approved”.
Energy approved or energy starred HVAC units can save home owners over $115 each year on annual household energy consumption One problem with the energy star system is that it is voluntary This means there is no legal requirement for HVAC units to be tested and awarded an energy star Despite there being no legal requirement for certification Most HVAC units undergo this voluntary measure and carry the energy star.
SEER (Seasonal Energy Efficiency Ratio)
This is a cooling efficiency ratio used for heat pimps and air conditioning systems The SEER works in the same way as the AFUE energy rating system The higher the units rating The more energy it consumes Meaning consumers will pay more in utility bills.
HSPE (Heating Seasonal Performance Factor)
This is a system that measures heating efficiency in heat pumps The rating system works in the same way to SEER and AFUE The higher the rating The more energy is consumed.
Creating Efficient Environments.
High performance HVAC units help to conserve energy They improve IEQ (indoor environment quality) This is achieved by offering improved user thermal comfort, High performance HVAC units can reduce a users energy bills by approximately 30%.
When a HVAC unit is installed in conjunction with a buildings designs A higher level of savings can be created In a period of 3 to 5 years the savings are 30% The savings increase to 70%, when the period is extended to 7 years.
To incorporate a high performance HVAC unit into a new building The design of the building must be considered As the building must contain features to reduce cooling and heating necessities Such as incorporating passive heating and cooling measures This can be achieved through the use of sun control and shading devices.
Other suggestions include the use of an “air retarder” system in the exterior walls Also included should be glazing with a high cooling index for internal-load dominated structures The HVAC units should also be the correct size for the building.
When choosing the correct size of HVAC unit A system should be selected that is comparable with the required capacity If the unit has a capacity that is too high The additional capacity will never be used This will result in the HVAC unit not being cost effective in it’s energy consumption.
In this instance HVAC units that excel as part of load performance for variable volume or variable capacities for cooling fans, cooling towers, pump systems, boiler plants, and fan systems Should be selected You will also need to shave off the workload and determine the peak and off-peak, differences This will help to avoid unnecessary peak-demand charges.
Maximizing Efficiency Through Load Control
There are different ways of achieving higher efficiency in each HVAC unit If using a heating system, a condensing boiler is recommended to achieve higher efficiency A condensing boiler will reduce the chances of breaching As any surplus gas will be directly vented outside. Condensing boilers offer approximately 98% combustion efficiency and are usually powered by natural gas They are connected in a “modular installation” They offer a more efficient working-part load than non condensing boilers.
For heating control, you can achieve higher efficiency By reducing the on-off cycle of the boiler By Utilizing modulating boilers that constantly adjust heat input to match workload effectively You will reduce energy consumption. If you assemble small boilers in to a group of modular plants you will further reduce the work load As the boilers can be taken on and off line depending on the need.
The most efficient ventilation system available on he market is the VAV (Variable Air Volume) unit These units are capable of working with variable work loads and consume less energy, while maintaining a good air flow.
Another way of conserving energy is through the use of “Raised Floor Air Distribution” This system defuses the temperature by directing warm air upwards towards the ceiling This system will maintain a constantly comfortable air flow VAV system controls are capable of working with small loads VAV systems should be used to strike the correct balance between supply and return airflow.
For use with air conditioning systems It is recommended to use “Explorative Coolers” also known as “Swamp Coolers” Explorative coolers greatly reduce peak demands with their mechanism The mechanism cools the air whilst humidifying the air at the same time By evaporating the moisture Explorative coolers conserve energy.
A condenser that conserves energy is, “The Waterside economizer” This will conserve energy greatly On situations where the temperature is cool The waterside economizer utilizes water loops to chill the water Allowing the condenser to maintain a cool temperature, with out the need to use the chiller.
An integrated chiller plant is more difficult to achieve However it is more efficient than any other air conditioning control method This method optimizes through monitoring air conditioning strategies This system achieves the minimum required energy cost for cooling towers, fans, pumps, and combined chillers.
The heat recovery process plays an essential role in achieving optimal energy efficiency The most efficient option at this time is through the use of desiccant wheels, as they hold 85% efficiency and are capable of recovering both latent and sensible heat. This method of de-humidification works by retrieving moisture from air streams The moisture is then exposed to a secondary air stream via the rotating the wheel.
The Installation of an energy efficient HVAC system will initially result in more upfront costs. However it is an investment that will achieve large benefits in the long tern Both in terms of environmental savings and through larger financial savings In the reduction of energy consumption.
Conserving energy doesn’t have to be a complicated process Through effective planning and preparation engineers that follow these steps are able to provide their customers with large savings Through the installation of energy efficient HVAC systems.