Re: Electronically controlled HVAC damper?

[Byron Hynes <bph@xxxxxxxxxxxxx>]

Thanks. Sounds like some really good thoughts

I don't think I'm quite ready to DIY for zoning, but I am going to be rather
specific in some wants with whatever contractors I might use. For example,
I want fully communicating thermostats, regardless of what type/brand/label
they would prefer to sell me. I don't think most of the guys around here
understand when you say "the thermostat has to connect to my Automation system",
but, we'll see.

> While automating your HAVC system two other suggestions:
>
> 1) install a flow switch to shut down the heat or a/c if there is low
> flow. Problems such as broken fan belts can result in a burned out a/c
> compressor if your not home and it keeps running with no air flow
> trying to answer a cooling call.  This would also address the problem
> of too many regisers being closed.  You'd need to find a flow switch
> from an HVAC distributor.
>
> 2) a smoke detector in the return air duct (commonly used industrially
> and in commercial buidings, but not in residences) could save your
> life by shutting down the system if smoke is detected, otherwise a
> modern forced air system can efficiently fill the whole house with
> smoke or CO from a fire in one room.  Also, connect your central fire
> alarm (if you have one) to shut off the system in the event of fire
> for the same reason.   Smoke detectors for use in air ducts are
> available commercially.  In our highrise building, the system switches
> to full fresh air at max fan if the fire alarm goes off, but shuts
> down if smoke is detected in the ducts.
>
> Just a thought
>
> "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote in message
> news:dsudnT84DvihVWXeRVn-gQ@xxxxxxxxxx
>
>>> Is it enough to make sure that at least one zone is open? or is it
>>> more
>>>
>> complicated?
>>
>> It depends on the setup.  If you short-cycle a furnace, you run the
>> risk
>> of
>> cracking the heat exchanger and allowing CO into the house.  It all
>> depends
>> on the unit's safety features and configurability.  You need to know,
>> at a
>> minimum, how much the air heats up from furnace air inlet to outlet.
>> If
>> it
>> leaves the furnace at say X degrees unmodified but X+30 degrees after
>> your
>> zoning, you need to do something because you've lowered the over-all
>> airflow
>> through the system too much.
>> If you are going to DIY zone, factor in the cost of several good CO
>> detectors and place them strategically throughout the house.
>>
>> --
>> Bobby G.