Faced with Home Manager retirement, what should a homeowner do? Know your House Facts.  By design, “Variable Air Volume” is the foundation of your house mechanical systems sizing, ducts, sensors and electronic controllers which optimize comfort and operating efficiency.


Know your House Facts:  House “Characteristics" with Home Manager and VAV method. -



1) HVAC ducts are designed for multi-zone VAV operation.
2) HVAC ducts are over-sized by design to work optimally in a VAV system.
3) HVAC ducts are not equipped with "balancing" dampers since VAV is “self-balancing.”
4) By design VAV may have fewer air supply registers in room/area than conventional systems.
5) VAV method monitors temperature in each room/area (not average temperature in a hallway).
6) VAV method heats/cools specific areas per specific requirement. (cools gym, not her office).
7) VAV method adjusts according to active solar loads  (if South too hot or North too cool).
8) VAV delivers both personalized comfort and house-wide efficiency harmoniously.
9) VAV efficiency permits reducing 1 ton of capacity under Title 24, saving on initial costs.

Abandoning your designed VAV method will revert your house to a non-zoned configuration. Be aware this will affect your house comfort, efficiency and energy costs.

Know your House Facts: House “Characteristics" without Home Manager and VAV method. -

1) Cost of HVAC operations will increase at least 30%.
2) Longer average time required for areas to reach desired temperature comfort levels.
3) Some areas will not reach desired temperature under certain internal and solar loads.
4) Some areas will overshoot desired comfort temperature levels causing hot/cold spots.
5) First floor comfort temperature determined by a single sensor (or thermostat).
6) Second floor comfort temperature determined by single sensor (or thermostat).
7) Cooling one bedroom cools all bedrooms.  (Like controlling room lights from breaker box.)
8) Solar loads (East/South/West) create uneven temperatures (too hot/cold) in daylight hours.
9) Reduced tonnage capacity (per VAV design) insufficient for highest heat/cool demand.

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Tags: HVAC, Home, VAV, automation

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Replies to This Discussion

It's hard enough to get homeowners to buy complete systems instead of just doing a condenser swap, much less buying an expensive VAV system. What is the difference between VAV and conventional zoning?

The Home Manager multi-zone controller operates the "Direct Air" VAV method, not a bypass method as in conventional residential zoning. The "Direct Air" VAV method introduced in 1985 is proven to be efficient and effective. However, the Home Manager electronic controller is reaching end of serviceable life leading some owners to abandon VAV and revert to conventional or non-zoned HVAC configurations. The article "Know Your House Facts" informs owners and contractors of the benefits of maintaining and draw backs of abandoning their homes existing VAV method. I believe bypass method is now banned for new or expanded residential zone control systems under California 2013 Title 24 regulation.

So VAV is just a zoned system that doesn't use a bypass damper? If the ducts were oversized at the time of initial installation a conventional zoned system wouldn't need a bypass damper either. I never understood the whole bypass damper thing, it defeats the whole point of saving energy with a zoned system. It's much better to set up a zoned system where the zones that aren't calling are opened a little bit to relieve excess static pressure. Better yet just go with separate systems for each floor...

Are you suggesting homeowners replace the control module but keep the rest of the system? Is there a current module compatible with the 30year old system? Is it proprietary or can it be controlled with a conventional zone controller?

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