Re: Why would I want to use thermostats with the M1-G?

[Lewis Gardner <lgardner@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

RayWBo@xxxxxxxxx wrote:
> Was just thinking and trying to plan out what I need to implement the
> ELK M1 in my home. In the area of temperature control, I have a
> hydronic warm air system with A/C - 2 air handlers, one which has 2
> zone dampers.
>
> In looking at thermostats (HAI models), I then questioned if I even
> need them - and might be better suited to simply using temperature
> sensors in the place of the 3 themostats. Am I missing something or
> does this make sense?

The main reason to use thermostats is as a demarcation and user
interface to the HVAC system.

In your own home this might not be needed. If you are comfortable with
servicing your own HVAC system the demarcation between HVAC and
automation isn't an issue. However if you have problems with the HVAC
system be ready for whatever brain dead tech that comes along to blame
any problems on your automation system and try to sell you a whole new
HVAC system.

Thermostats present a fairly friendly user interface that most people
can understand. You may be able to make a better interface with a
touchscreen (especially for a 3 zone system) but not everyone will look
for temperature controls in a non-thermostat type device. Once again, in
your own home this might not be a problem unless you regularly have
house sitters, guests or others that might need to adjust the temperature.

One other item is that thermostats have a anticipation feature that will
start the unit before a set point to make the temperature more even. You
should be able to code a feature like this.

I have a similar issue in my house. Since it is a older house with 2
floors, a single HVAC unit and no return air from the second floor a
thermostat does not work effectively in the summer. I solved this
problem by using a Homevision to run the AC according to duty cycle
instead of temperature. My control relays run in parallel with the
existing thermostat and I set the duty cycle to 0 minutes per hour when
the HVAC guy comes. I pick up the current HVAC status via debounced LEDs
across the existing thermostat contacts. This way the Homevision knows
when the thermostat last ran the AC and won't short cycle of run the AC
prematurely.

Since I have gone over to a M1 I am now debating myself whether to get
an controllable thermostat (RCS) or migrate the programing over to the M1.