We had Sense installed on March 1. Our bill cycle runs roughly on the 14th if every month, so we had 1/2 a bill cycle to see the difference Sense could make, and what a difference it was!
Right away, we identified a space heater running in the trailer (we have renters) instead of their gas heat. We convinced them it was cheaper to use gas, and immediately saw a difference in our daily usage stats.
Additionally, we set a Sense goal to stay under 40 kWh daily. Just being mindful of the impact each device has in Sense, I think we made small changes to how we used electricity. All days since they switched to gas heat have been under 30 kWh, most under 25, and one day was 19.1.
Today, I took a look at my bill (the last half was with Sense, the first half without). We used an average 16.5 kWh less per day this month than we did 2 months ago then the average daily temp was 1 degree different! At 14 cents per kWh, thatās a $69 savings.
This monthās average is still skewed by the high usages pre-Sense, so Iām definitely looking forward to seeing next monthās bill!
I had a similar experience with heat. The HVAC tech connected the thermostat so the heat always defaulted to resistance heat instead of heat pump. Just like you I would not caught it if sense data hadnāt enlightened me.
For an all-electric home in temperate climates, the emphasis is on AC. The heat comes from running the AC in reverse, called a heat pump, or resistance heat strips. Because of the efficiency of heat pumps you always want to avoid using the resistance heat.
The problem with Heat pumps is they lose efficiency as the outdoor temperature drops, say below forty.
Most heat pump systems work by alternating with the heat strips for lower temps or only heat strips when the thermostat calls for a larger increase in heat. Most thermostats default to three degrees for heat strip only heat. Every thermostat that I have seen has heat, cool, or emergency heat choices. Emergency heat is resistance heat only.
What was done in my case is the heat pump refrigerant reversing valve wire was not connected so the only source of heat was resistance heat. That is approximately 125% more expensive.
How this knowledge can relate to an AirBnB or your home, if it has a heat pump to save KwH: increase the home temp in two degree steps, or shut off the ability to use heat strips. Some thermostats have this capability such as Sensi by Emerson.
True story: I had one renter who made over 110 temperature changes in a month. He would set the AC to super cool the home for sleeping, wake up and set the heat on, which called for resistance heat, overshoot his comfort temp after a few hours and turn on the AC. I caught this after I saw a large utility bill. I bought Sense shortly after and disabled the heat strips for all but the colder days.
It can get a little complicated about how thermostats wired and especially setup. If you want the ultimate control of your HVAC then you need a thermostat that is for TRADE USE ONLY. You wonāt find these anywhere in a retail store. These thermostats make even the most advanced ecobee look basic.
But they offer the ability to take total control of your system and lockout either auxiliary or outside unit at specified temperatures or points.
Thatās an interesting take on thermostats, never heard of those. For anyone in a rental situation you have to ensure the thermostat is simple enough to operate. People do better with tactile control. Touch screens cause problems, too many options is asking for a trouble call. I have had people set the āscheduleā option and complain to me when the temp changes. I guess I would some it up by saying that completely rationale intelligent people can do some pretty dumb things.
Donāt even get me started on the engineer who wanted to help me out by adjusting my golf cart carb. That would have been a problem since it is fuel injected.
These thermostats have two levels of operation. There is the installer portion and the normal operation portion.
In the installer part, you can lock out or set limits on adjustments. Letās ay someone want to raise the heat to 80, you could set the maximum to 78.
It could also be setup so no matter what, the auxiliary heat would not come on.
That thermostat I ha e locked out so nobody can change the settings. Without a working knowledge of installer setup, they would t know how to get in and code it anyway.
I should mention Iāve learned most of this the hard way by doing ādumbā things. I went through 3 WiFi Honeywell thermostats before learning I needed something with more capabilities than off the shelf would offer.
Mine offers these options most of which are only controlled by a phone app making them tamper proof:
Auxiliary heat off (heat pump only)
Temperature offset
Humidity offset
Control lock
Control the cycle rate
Set short delay when AC is quickly turned off to protect equipment
Display options such as backlight on or show the humidity
By subscription for 10.00 a year you can control multiple thermostats on one screen and sent min and max temp ranges
Iām currently using two brands. I have a Honeywell 8580 wireless at home and a TRANE TCONT802. at the store.
The Honeywell is wireless and has pretty much the same settings and features as yours.
The Trane is the trade thermostat.
In addition to everything you listed, this one has the outside sensor for temperature which also can be used to set control parameters. It supports inside remote sensors and humidity sensor (not using) and a long list of things I never knew existed in HVAC controls.
A couple things I really like. I have it set so that above 52 degrees the gas backup heat wonāt turn on but if itās 35 outside then it will come on but the heat pump wonāt. I also have the differential temperature inside changed to 2 degrees instead of the standard 3 that is default in most thermostats. These settings and more I either canāt think of right now or donāt use are available. The downside on this one is not being WiFi.
I did have a Honeywell WiFi there for awhile until I ran into a compatibility issue when cold weather came and Honeywell doesnāt charge extra to access multiple thermostats on one account at multiple locations, all through the web or their TCC app
Does the Honeywell 8580 have geo fencing, i.e. automatically set back the temp as you leave and approach the property? The Sensi offers this. To me that is one on the best features for painless energy conservation.
The 8580 does not that I know of but I remember the 9580 does. I was shocked to see just how many thermostats they made. In the 8580 class there were several different models, mine is on the lower end so another might.
I wasnāt looking for geofencing as I would rather control manually from my phone and not lose the āadaptive recoveryā feature.
Thatās hilarious @mike_gessner
Very true with me. The WiFi thermostat sends me notifications when someone tries to override my settings and I act just like him, tracking down the culprit. Having my heat pump detected has added another layer of āsecurityā.
The wife is happy I had to take the WiFi off her store thermostat, now she can do what she wants. Great link!
My wife says thatās how I am with the thermostat but she changes it constantly and will always turn it to just heating or cooling even though Iāve told her to leave it on auto and to just set a range that she wants the temperature to stay. It drives me crazy
Be careful with scheduling a thermostat on a heat pump. It could cost you more $$$. Ex: you set it at 70 unnoc and 73 occ, when occupied mode starts your aux heat ( could be electric or fossil fuel) could kick in because of that 3F delta temp. So everyday you would use electric heat to gain that extra comfort.
Balance point and aux heat lockout are 2 settings your thermostat must have. Sometimes theses parameter only show up when and outdoor sensor is present. I ALWAYS use a thermostat with the ability to know the OD temp (through a wired or wireless sensor or through wifi) when the unit is a heat pump.
One thing iād like to see in a residential thermostat is a setting like Ā« allow scheduling only over aux heat lockout setpoint Ā» or Ā« disable aux heat for x hours after any period switch Ā».
@samwooly1 your Trane thermostat is a rebranded obsolete Honeywell Vision Pro 8000. They have been replaced by the Honeywell prestige serie thermostat. They are now WiFi and have a color screen plus more advanced functions.
Uploading: CB7107DC-CC38-40C0-AEE4-19476EFECE47.jpegā¦ Are you sure about that @HVAC_Marc, they donāt look the same and donāt have the same setting in installer menu.
The Honeywell I have is for sure visionpro 8000 as itās the 8580 model. I know there are at least a dozen in this 8000 series.
Another reason I wasnāt thinking it was a rebranded 8000 as I could find one that would handle dual fuel on a heat pump system. The Trane does.
I would like a WiFi Honeywell for the store but the problem Iām running into is how the fan kicks in while hearing with fossil fuel. All the thermostats i ha e tried default to the thermostat controlling fan in heat mode. I need fan control to be done by system when burning fossil fuel but controlled by thermostat when in heat pump mode. The last working Trane thermostat I had was not programmable and I had to cut a wire in it for it to work like this. It was a TCONT402 I believe.
If you could suggest a WiFi Honeywell for me, I would greatly appreciate it.
On second look, they are very similar.
Thought Iād just wrap this up with a pretty screenshot. You can see on the 8th we had the renters switch to propane heat instead of the electric space heater running all night.
I did the calculation for our natural gas and electric rates (Colorado, see screenshot below) and for us electric is 5.8 times more expensive than gas, per unit energy. So direct electric heating is much more expensive.
As someone that uses all three of your examples, I feel natural gas gives you the most for your money. There are experts that will talk about how electric is nearly 100% efficiency while gas can be below 80 and up to 90% efficient.
Propane is just too expensive. I still use it but only about 100 pounds a month.
Electric heat also does t feel the same as gas, thatās important. Iāve had even better heat sources for comfort and cost like wood and especially corn (yes, Iāve heatwd burning nothing but corn).
If I go by but production cost, where I live we get briās at the lowest cost from natural gas.
