How to Attach Heat Recovery Ventilation to Existing Ductwork

What You'll Need
Heat ventilation system
Furnace ductwork
120-volt electrical outlet
Rain proof vent heads
Insect/duct barrier
Metal flexible ductwork
Floor drain
Drain tubing

A heat recovery ventilation system is a heat air exchanger that pulls fresh air into the home through a vent to the outside and prevents a build-up of stale air in the ducts and the home. Most modern homes have a vapor barrier installed over the insulation that prevents air from entering or leaving the home and often this causes a build-up of humidity that can accelerate the growth of mold. The heat recovery ventilation system will distribute fresh air to every room of the home. If you have an unfinished basement you won’t have to cause any damage to walls or floors, but installing one when you have the basement completed can incur an extra expense. You can also install this system in the attic, but this may mean you have to run additional ductwork.

Step 1 – Find a Central Location

A heat recovery ventilation system should ideally be located in a central place so that all rooms are about equal distance from it. The basement is the best location and as close to the furnace as possible, but you must also have a 120-volt electrical outlet close by. If you do not have this you should look into having an electrician install one for you.

Step 2 – Install a Support for the System

You need to place the ventilator on a strong support surface – concrete or one that you build especially for this purpose. The units are quite heavy – often weighing as much as 80 pounds. You will need help moving it into place.

Step 3 – Install Vents on the Outside Wall

The system has both exhaust and intake ducts that must be connected to the outside. Using a saw cut holes in the exterior wall to fit the size of the ductwork. Measure the exhaust and intake ducts on the system – normally they are 4 or 6 inches in diameter. Install the rain proof vent heads and insect/dust barriers over the holes for further protection from nature.

Step 4 – Attach Flexible Hose and Ductwork

Attach one end of the metal flexible hoses to both the exhaust and intake hoods. Attach the other end of the hoses to the ventilator.

Run flexible ductwork from the furnace to the intake outlet so that fresh air can come into your home.

Attach flexible ductwork to the ventilator and run it to the exhaust duct to take stale air out of the home.

Attach drain tubing to the main system and run it to a drain in the floor. This will take care of any condensation that builds up in the ductwork.

Step 5 – Plug in the Heat Recovery Ventilation System

Plug in the unit to the 120-volt outlet and make sure that it is working properly. You can set it to run continuously if you wish and then you do not have to worry about turning it on and off.