Energy Recovery Ventilators
It is so important to bring fresh air into the home, whether it is in the cold of winter or the heat of summer. Failure to exchange air can cause all kinds of problems in the home in addition to having a negative impact on the health of those who live there.
Energy recovery ventilators are usually installed as a central, whole-house system, but small window- and wall-mounted models are available as well. The whole-house models may have separate ducts or share ductwork with the HVAC system. Energy is recovered by using one or more fans to force air across a heat exchanger.
Two Types of Energy Recovery Systems
There are two ERV systems on the market that recover some of the energy used to either heat or cool the air in your home or commercial building. Heat-recovery ventilators (HRVs) transfer heat from the air in the building to incoming air through a heat exchanger without transferring moisture. Heat recovery ventilators don't offer very good humidity control during hot, humid summer conditions, and air becomes very dry in the winter.
Energy recovery ventilators (ERVs) use the heat exchanger to transfer some of the moisture in the air along with heat or cold to the incoming air. This keeps the humidity in the building in better balance during both winter and summer. During the summer, the process is reversed where the air being exhausted takes up moisture from the incoming air and reduces the humidity in the house in hot, humid climates. In dry climates, moisture in the air isn't expelled completely as it is transferred to the incoming air.
Efficiency of Energy Recovery Ventilators
Energy recovery ventilators recover between 70 – 80% of the energy that was used to heat or cool the air leaving the building. This is especially true when one of these systems is installed in extreme climates. For example, an energy recovery ventilator easily pays for the extra electricity the fans consume when summer temperatures soar. That cost savings isn’t nearly as high when temperatures are mild, or fuel costs are low.
Similarly, areas that see very cold winters benefit from considerable energy savings after an energy recovery ventilation systems is installed. The cost of operating the fan is more than compensated for by the reduced use of fuel or electricity to heat the air coming into the home.
Energy Recovery Systems Installation
In general it’s more cost effective to install a ventilation system that shares the existing ductwork, in situations where this is possible. This reduces maintenance as well as installation costs. This is especially true if the home is being retrofitted with an ERV. Because each room should have a supply and return duct, sharing existing ductwork obviously saves money.
Whether ductwork is shared or new, it is important to insulate any ducts that pass through unheated spaces. Sealing joints with duct mastic is also important to prevent air loss.
Where winter temperatures consistently drop below freezing, the heat exchanger must be protected from freezing. This is a common occurrence when air flowing into the exchanger is cold enough to form frost. This can damage the exchanger while it also reduces the ability of the exchanger to ventilate properly. A longer initial run before air enters the heat exchanger can help to pre-warm air.
Concerns with Energy Recovery Ventilation Systems
One of the major concerns with ERVs is the fact that mold and bacteria can build up on the heat exchanger surfaces. This means that a regular cleaning schedule needs to be implemented. Such build-up not only increases harmful particulates in the air, it also causes the ventilation rates and heat recovery rates to go down.
In Florida, an energy recovery ventilation system can provide serious energy savings in both homes and commercial structures. It can also be part of a system that guarantees healthy air while you seek a comfortable living and working environment. Baker & Sons Air Conditioning has many years of experience servicing both types of energy recovery ventilation systems. Call us today. We'll help you choose the right energy recovery ventilator for your home or commercial building.
We have been helping maintain the healthy indoor air quality in Sarasota, Manatee & Charlotte County homes and businesses for over 23 years. Discover why our energy recovery ventilators are right for you.