What is a heat recovery ventilator?

A heat recovery ventilator is a fan system that:

1. Takes fresh outside air and delivers it into the home.

2. Takes stale house air and blows it outside.

3a. Exchanges the heat from the stale air blown outside to the fresh air coming in. (Winter).

3b. Exchanges the cold from the stale air blown outside to the fresh air coming in. (Summer).

What sort of heat recovery can I expect?
The efficiency of the Airiva HE100 is 82.2%.
This means that 82.2% of the energy contained in your heated or cooled house air that you blow outside is recovered!

How is the heat exchanged?

The energy is transferred from the warm air stream of the air being exhausted to the cool fresh air stream of the air being taken from outside (in the winter) in the core of the heat exchanger. This core consists of thousands of adjacent air channels through which the air flows. The material that the core is made of has a certain heat transfer coefficient. The core of the Airiva is made of Polypropylene. The material is not important as long as it is corrosion proof. Some cores are made of fiberglass, aluminum, copper, mylar, ceramics and other materials. The total surface area that the air is in contact with is important.

How much power does the Airiva use?
The power consumption is about the same as a 100 Watt light bulb.

Is it difficult to install?
Not difficult, but it involves a few things. An accomplished DIY person should be able to complete the job in 4 to 8 hours. (After you have collected all necessary tools and materials, see below). Please note: the installation materials are not provided.

What are the major tasks in a basic installation?
1. Determine the location for the Airiva.
2. Install a support for the unit. The Airiva weighs almost 70 pounds.
3. Install a 6" diameter duct for the fresh air intake to the outside of your home and install a rainproof vent cap.
4. Install a 6" diameter duct for the stale air exhaust to the outside of your home and install a rainproof vent cap.
5. Run a short length of 6" diameter duct for the fresh, conditioned air to a central location in your home, i.e. hallway or upstairs.
6. Run a short length of 6" diameter duct to pickup stale house air. Preferably near your forced air system and/or in a basement.
7. Install the condensate drain in the Airiva housing and run a 3/8" diameter hose to a nearby floor drain.
8. Plug the Airiva into a 110-120 Volt AC grounded house outlet. Note: The Airiva, as dictated by the National Electrical Code, only has a 2 foot long power cord, so you may have to install a dedicated grounded outlet near the unit. View the Airiva Installation Page

Can I connect the Airiva to my forced air system?
Yes. Details of such installation are covered in the installation manual. This type of installation is only recommended if your central forced air system runs continuously at a low speed on a year 'round basis. You will need an air velocity meter that reads in Feet Per Minute (FPM) to properly adjust the airflow through the Airiva.

Can the Airiva freeze up when it is really cold outside?
The Airiva has a built-in electronic thermostat that will shut the unit fans down when certain low temperature limits are reached to prevent freeze-up.

How big a home can the Airiva service?
Recommendations from Government Agencies are a minimum of 8 air exchanges per day for your home.
The Airiva HE150 is rated at 150 Cubic Feet per Minute (CFM) airflow, nominal.
In a normal installation, with restrictions from connecting ducts, the airflow is rated at 120 CFM on high speed.

To calculate your requirements take:
House square feet x ceiling height and divide by the Airiva CFM rating of 125 CFM (on High speed).
I.e. a bungalow 1800 sq. ft. x 8' ceiling height = 14400 Cubic Foot.
Divide by the Airiva flow of 125 CFM = 115 minutes to move all the air. Round to 2 hours.
Per day you will get approximately 12 air exchanges in your home.
Since this example is based on an 1800 sq. ft. bungalow, the Airiva would give 6 air exchanges per day for a 3600 sq. ft. home. In the 1800 sq. ft. example we recommend running the Airiva on 'Low' speed for about 7 ½ exchanges per day.

Does the Airiva need servicing?
Yes. The Airiva includes a standard 12" x 12" air filter that should be washed at least every three months of operation; more often in heavily polluted areas. The heat exchanger core, which is easily removable, must be hosed down at least once a year. You can do this in the sink or outside with the garden hose.

Is the Airiva safe?
The Airiva contains only components that have been rigorously tested to the Standards of Underwriters Laboratories Inc. (UL®). The blower motors are thermally protected. The housing has a safety interlock switch and the housing is a heavy gauge sheet metal.

What tools and materials will I typically need?

TOOLS: Power drill, power screwdriver, file or sheet metal reamer, reciprocating saw to cut 6" diameter openings through house wall, tin snips, screwdrivers, pliers.

MATERIALS: Strong shelf brackets with screws (wall plugs if brackets are installed in concrete wall), materials to install a 110-120 Volt AC outlet for the Airiva. 6" sheet metal take-offs (collars), 6" duct pipe and necessary elbows, outside rainproof vent hoods, manual 6" duct dampers, duct tape, self piercing #8 x 1/2" sheet metal screws to fasten 6" ducts and elbows, quality caulking, 3/8" ID clear plastic hose, screws to fasten vent hoods. Note what ends you need on the sheet metal parts, i.e. crimped or un-crimped. The four connections on the Airiva are crimped. Band-aids if you are not used to working with sheet metal.