TOPIC: HVAC

I inspected a new house today and noticed the blower for the HVAC unit would periodically come on and off like you would think it normally would, only the thermostats heat cold switch was in the off position and the blower was in the auto position.  Everything tells me this should not be happening as its in the off position.

Is this a new feature or just not working correctly?

I checked the temp as normal and it looked good.  But when the blower was on while the thermostat was in the off position the temp was just about the same.

Any thoughts?

If the blower was in the auto position it sounds like it's doing what it was supposed to, circulating air? What was the temperature it was blowing at? Same as it was inside the house?

It was about 2ºF cooler.  Basically the same.  Problem is, when the heat/cool switch is in the off position the unit should not come on at all.  The blower switch has an auto/on position.  If its in the on position it will stay on all the time.  If its in the auto position the blower should only come on when the heater or the AC kicks on then it should shut of when the heat or AC shuts off.

Okay the buyer found out some info and got back to me. 

They said "I believe our home is equipped with a indoor air ventilation system with a fan recycler that recycles the air on a timed basis.  I believe this feature runs on a timed basis and will run even if the thermostat is turned off."

This was what I thought might be happening but had never seen this before.  Have any of you ran into this before?

John - I didn't see this post until just now.  If I don't see a new post entry I don't check them.  Should check more often!

Sounded like an upgrade filtration system when I first read it.  If they don't have a special filter in there, it may call for one, or is designed for one.  Did they buy it because of an asthmatic in the house? 

Air movement is the new wave.  Keeps down stagnant air, mold development, temperature variations and so forth.  Filters the air well.  They are good systems and use little energy.  Your people were smart to get it.

This house was designed to be very energy efficient (lots of insulation).  I explained to the buyer some of the draw backs to heavily insulated homes and pointed out some of the features they added to the house to allow it to breath (vents of the doors for every bedroom). 

Because of the energy efficient design, I wondered if the HVAC was designed to circulate the air but had never seen one do it.  This was a first for me.  It makes sense!!!