I have a Venmar Constructo 1.5 air exchange unit. We have 100% electric heat, so there is no furnace hooked up to this.
The fresh air duct from outside (before it gets to the unit) is about solid ice. It is insulated round tubing style duct.
The unit itself seems to be working fine, as our humidity stays lows (no buildup on windows, etc.) The problem is now the ice buildup has started on the outgoing end as well (to house post system). I think all the ice build up is making the unit heavier and out of level, so some of the water from the defrost cycle leaks out in different areas, instead of the through the drain hoses. Not to mention once the weather warms up, the duct will drip everywhere (this past spring I had to poke holes in the duct to drain it, as it had a huge bulge of water).
The co. that put it in has come out twice. The first time they said the unit wasn't balanced, so that created the buildup. The second time they said the incoming vent was taking on snow, as it was to the north, where we get most of our wind, etc. So they changed the location of the vent to the side of the house.
Well, it is still freezing up.
Is this normal? The defrost cycle comes on 4-5 times an hour.
I have a feeling the incoming cold air is limited as it tries to enter the unit, then "sits" in the duct and freezes.
They are coming out again in a couple of days to look at it.
I would appreciate a couple of ideas as what to ask the tech. on why this is happening. I suspect they do not know.