Re: [PLUG] Off Topic: HVAC

[Mark Bergman via plug <plug@lists.phillylinux.org>]

In the message dated: Sun, 27 Feb 2022 02:02:13 -0500,
The pithy ruminations from John Karr via plug on 
[[PLUG] Off Topic: HVAC] were:
=> I've had discussions with other people in this group about HVAC. I'm 
=> about to do a major upgrade and could use advice.
=> 
=> On topic for this list would be discussion of controls, I would like 
=> something with multiple sensors for temperature and humidity, easy to 
=> program, yet secure.

The primary question is whether you want the controls to be solely within the HVAC vendor's proprietary ecosystem (expensive, no/limited integration to other home systems, limited
flexibility, completely supported by the installer & manufacturer, likely dependent on a cloud service -- possibly via subscription) or whether you want to control the HVAC through a
separate home automation system.

Without a home automation system, you're limited to whatever sensors the HVAC vendor provides for temperature & humidity, and the type & quantity they support.

Assuming you've got a home automation system, you'll have a very wide choice of devices that report temperature. For example, I've got about 5 motion detectors that report temp + humidity
and another 5 that only report temperature, plus about 15 water (leak) detectors that report temperature, so I can easily program heating & cooling based on [weighted] averages across the
whole house, per-floor, per-room, etc,, and adjusted for occupancy (ie., if there has been motion recently).

I've been using Hubitat as my home automation system for several years. The "easy to program" aspect is debatable, but the security is quite good -- all processing takes place locally,
there's no need for any internet access.

The Hubitat system is closed source, but fairly "open" when it comes to user-contributed drivers & applications. 

For secure HVAC control, you've got a couple of choices:

	1. smart control of the HVAC system through the thermostat

		pretty easy with an HVAC unit that uses wired controls,
		with the addition of a 3rd-party networked thermostat
		(ie., Centralite Pearl with Zigbee, GoControl with Zwave,
		etc). Be careful about vendor thermostats that claim
		to be "smart" -- some may still require a connection
		to a proprietary cloud service for management, despite
		using standard RF protocols (Zigbee or Zwave). Daiken
		is the only mini-split HVAC system that I'm aware of
		that offers Wifi modules that do not require cloud access.

	2. smart control of the HVAC system through an infrared or 433 Mhz RF remote control

		You'll need a bridge between the remote control interface
		{infrared or 433MHz} and ethernet that can be managed
		through a home automation system. The Broadlink RM
		units are cheap & popular. They may require an internet
		connection for initial setup, but afterwards can be
		managed locally. One downside to this method is that
		it's one-way communication -- there's no feedback from
		the HVAC system to the bridge.


=> 
=> Off topic is ductwork, contractors, furnace, humidifier, and central air 
=> equipment. Please contact me off list about these.

I'm looking at adding another mini-split (likely Daiken) to my home. I'm already using Hubitat to manage 3x Fujitsu mini-splits via Broadlink RM3 and RM-Pro repeaters. I formerly had a
GoControl ZWave thermostat (which I liked a lot), but moved to a Salus system when we changed our heating system to multiple zones. The Salus includes wireless (battery) thermostats with a
nice physical interface and uses Zwave for communication ... but it's not integrated into Hubitat and they don't publish an API, so I'm currently using their cloud-based system for control.
At some point I may dive into converting a [defunct?] github project to control a different Salus model via python into a Groovy (java-like, uck!) driver for use within Hubitat.

Happy to follow-up off list, and I'd be glad to hear about local HVAC vendor recommendations.

Mark

=> 
=> -- 
=> 
=> Minds gets scrambled like eggs
=> Get bruised and erased
=> When you live in a brainstorm
=> 
=> — Alice Cooper: Hard Hearted Alice
=> 
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-- 
Mark Bergman    Biker, Rock Climber, SCUBA Diver, Unix mechanic, IATSE #1 Stagehand
'94 Yamaha GTS1000A^1					      2015 Aprilia Caponord
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