Messages from the Edge, mid-August 2024
Where we are
To review, as your EcoDharma Doula, for the next 6 months, I will offer you a monthly contemplation on what is commonly called ‘Getting to Zero.’ Science tells us we have 25 years to reduce our emissions to Zero. We are looking at a carbon reduction diet, which begins by looking at the big picture. We wish to turn the right side to Zero by 2050 or:
(Lighting + Heating + Cooling + cooking + driving + refrigeration + embodied energy + heating water + utilities + gardening + vampire energy) – (Clean Energy we Produce or Offset) = (Everything we Use)
Each mid-month, I try to tackle ‘low-hanging fruit’: those simple things that may have a significant impact. Our August mid-month offering will cover temperature control, also known as thermostats. Again, there is so much that anyone can do, and how you control heat is one of them. Heating and cooling our homes consumes up to half our yearly energy demand.
Mechanical, Programmable, and Smart Thermostats
If we grew up with thermostats, it might be the dumb mechanical version that you would crank up when you wanted heat and crank down when you went to bed. The pitfall is turning the setting down when it is no longer needed. These were popular when energy was cheap and utility bills were not excessive. I am not sure you can even purchase a dumb thermostat anymore.
“Limbo lower now..Limbo lower now..how low, can you go?” – Chubby Checker Limbo Rock
A step up is a programmable thermostat that allows you to ‘set it and forget it’. You may have a summer schedule for cooling and a winter schedule for heating. You will be able to assign hours of operation that match the season. If you wish, you can override the current setting. Further, you may be able to have a weekday schedule and a weekend schedule. The requirement is that you are physically there to make adjustments.
“I’m sorry, Dave. I’m afraid I can’t do that.” – Hal, A Space Odyssey
A step up in price and convenience is the ‘Smart Thermostat,’ which enables all controls to be accomplished from your voice command (HAL?) or ‘Smart Phone.’ The thermostat can also sense the ambient temperature, learn from your behavior, and provide time-based reporting. If you are stuck downtown in a meeting or traffic jam, you can turn your heat up remotely so that you are greeted with a cozy home when you finally get home.
Efficiency Vermont lists 131 thermostats for sale (see list here) in various flavors: you can filter on the desired features. No matter what the cost for a replacement, the payback period that pays for the upfront cost is measured in seasons and not years or decades.
Installation
Generally, because you are probably replacing an existing thermostat, the installation will be straightforward and in the realm of Doing-it-yourself (DIY). There are exceptions:
Smart Thermostat and Wifi
Your smart thermostat will require Wifi. Your smart thermostat may also require 2.4G channels on your router. There are routers out there that only will operate with 5G channels. Because you are connecting to your wifi, if the internet is down, so will your ability to control your system. We had our internet go out for a week after a severe wind outage and would have been stuck without a backup thermostat.
Two controller redundancy
When installing a new smart thermostat, you may wish to keep your existing one as a backup should your internet connection fail. The phenomenon of things failing when you most need them also applies to thermostats: snow loads dropping branches, cutting power, and internet.
Required Common Wire
Depending on the age of your home, your existing thermostat may or may not have a C Wire or Common Wire that supplies continual power. Your upgrade may require you to have a C Wire to supply it. Here are instructions on determining if you do, or do not have a common wire and what to do if you don’t. (Hint: if you don’t already have a Common Wire it may be time to call your favorite HVAC installer.)
Heat Pump Control
Our cold-climate heat pump has around 100 unique settings that are not likely to be controllable through a commercial product. When installing a heat pump, I strongly advise using two redundancies to have a dumb and smart controller system. Because of the advanced settings, I recommend that one of the thermostats be supplied by your specific heat pump so that you can access the advanced settings you wish to control.
Hybrid Heat systems in Cold Climates
When moving to heat pumps in locations experiencing Polar Vortex conditions, a strategy of keeping your gas heat as a backup should the heat pump be unable to draw heat from the ambient air is known as a Hybrid Heat solution: when the heat pump shuts down the backup kicks in. This requires some communication between the heat pump and gas heat to mediate who is in control. This is a case where the specific controller will probably be required to ensure proper coordination.
By the way, rather than using this gas-driven strategy, consider using backup electric heat instead. If the electricity goes out, you will probably not have heat from either hybrid source. If you have electricity, then using low-power (500W) space heaters will allow you to heat the spaces you use. And because you have done the ‘[Insulate Tight, Ventilate Right’ work from the June Messages, you will need less heat and hold onto the heat longer, avoiding the open flames!
Summary
Our mid-month Messages are all about using less energy while increasing our comfort. Instead of working harder, we attempt to work smarter. Even when you have fully electrified and have requested that your electricity come from renewable sources, there are times when you are still drawing from carbon-burning generation. So, to do the least harm, we limit our demand to a comfortable minimum. Moving to a low-cost controller that lowers your demand while providing temperature control where and when needed. Be aware and prepared for some of the edge cases that are liable to happen.
And, remember:
“Do what you can, where you are, with what you have.” ~ Teddy Roosevelt