When people start to upgrade their homes, they will quite often comes across products that they are not familiar with. ERVs are a common example of this. They can be very useful as a part of a homes HVAC system, but the general knowledge of them is very limited. Lets go through what an ERV actually is, the benefits it brings to a system, and why Engineering Solutions is the best choice for your MEP engineering needs (i.e. designing HVAC systems that includes ERVs) in the New York area.

Energy Recovery Ventilator

ERV stands for Energy Recovery Ventilator, and is regularly referred to as an air exchanger and an ERV ventilation system. They are designed to be connected into the HVAC system in your home, office, or any other building. They pull fresh, clean air into the building and take out stale/unclean air. They consist of two fans and a heat exchanger that makes it possible to transfer heat and moisture between the two air streams. It transfers the heat and moisture in order for the building to retain heat while in operation, which is obviously quite important during the winter months.

As well as swapping out “dirty” air for clean, ERVs also trap pollutants, contaminants, pollen, allergens and many more. This is extremely important especially now, and it ensures that the air entering the home, office, indoor space is healthy and clean. You may not know that the air within most homes is at least five times more contaminated than the air outside! It is clear that this is a problem as people can spend more than 90% of their time indoors. This is why it is a smart idea to incorporate an air exchanger like an ERV into your home or office space, to get the fresh, clean, and healthy air that everyone deserves.

How Does It Work?

Let’s take an example, two air streams are flowing, one is at 70°F and the other is at 0°F. Under normal circumstances the two air streams would mix and create air of 35°F each. However, in an ERV the air streams transfer temperatures so that the 70°F stream becomes 0°F, and vice versa. This is the core theory behind ERVs, the air exchange. A stationary core device or spinning wheel uses the counter flow of air to take the stale air out of a building all while keeping the air temperature the same.

ERV wheels or cores cannot achieve 100% energy recovery however, they receive a rating depending on the environmental conditions to return a percentage of effectiveness which is certified by AHRI. These are typically defined under summer and winter conditions, and vary from region to region. It is important to note that other types of ERV products do exist, but for the purposes of this example we focused on the desiccant wheel and core theory.

Benefits of Using an ERV

There can be many benefits to installing an ERV on your home’s HVAC system. They include but are not limited to:

Removing and filtering out formaldehydes, allergens, and other toxins from the air indoors, also removes any contaminants that can be introduced into your home from an attached garage
Reduces the dependency on the HVAC system through the use of EconoCool technology
Reduces odors around the home produced from pets, bathrooms, cooking etc.
Increases the lifespan of your HVAC system
Reduces the risk of mildew and mold
Reduces dust build up produced from pet dander, pollen, and other materials
Improved sleep has been linked to clean, freshly cycled air
Keeps temperatures from room to room more consistent around the home
Is a quiet, efficient system that requires simple maintenance

Replaces an Economizer

Economizers meet code by mixing return air from a building with air from outside, and typically includes a barometric relief to remove the pre-conditioned air. However, this can come at a higher cost for the building owner, as when Free Cooling (when the outside air is the correct temperature to cool the space) isn’t available, economizers remove conditioned air and force the HVAC unit(s) to recondition fresh outside air.

ERVs can also extend the free cooling range by using cooler outdoor air than the set-point, and utilizing temperature recovery to temper it to the right temperature.

Downsize Your HVAC Unit

ERVs are designed to transfer Sensible and Latent Heat or just Sensible Heat. Latent gives the opportunity for the ERV to remove some of the humidity before the air even reaches your HVAC unit. A properly dialed in ERV will direct a large amount of the humidity straight out of the building by transferring it over to the opposing air stream. This gives the HVAC unit(s) less work to do, therefore allowing a smaller HVAC unit to be specified by the design engineer. If you are looking for a design engineer in the New York area, Engineering Solutions would be happy to consult you on your next project.

Energy recovery is a complicated subject, a multitude of other factors come into play that we did not mention in this article, so as to make it as easy to understand as possible. Specialist facilities like Hospitals, to Animal Shelters and Natatoriums have extremely strict indoor air quality requirements. Each situation will demand a different solution, to which a specific ERV will be matched to.

Will you be installing an ERV in your home or office? Do you think the technology is worth the price of installing it? Engineering Solutions would love to hear your thoughts in the comments below, and if you have any questions please don’t hesitate to contact us!