I have a programmable thermostat that is, well, dumb. It is willing to set times and abide by those, but it doesn't take in to account the weather.  What I'm looking for is a smart thermostat that can learn my behavior and also make decisions based on the humidity inside the house and the temperature outside.

NEST and other smart thermostats seem to be able to predict temperature but not more advanced analytics. Does anyone know a thermostat that can move with the weather? Especially for sudden warm or cold fronts, it makes sense to set thermostat based on temperature and not hours of the day. We generally keep our thermostat warmer in the summer due to the wide difference between RH and temperature inside and out. 80 feels so much cooler on a hot summer day than in a late spring heat wave.

Ideally it would be a thermostat that can raise the setpoint with the outside temperature (say 15degrees trailing, max 85 degrees) throughout the day and also based on relative humidity (say 60%).  Then, as the day cools down, lower the setpoint based on the outside temperature and the relative humidity (Leading 15 degrees with a floor at 72, 40%RH). This way I could minimize the deltaT while keeping my house relatively dry.  

Tags: Thermostat

Views: 233

Reply to This

Replies to This Discussion

There are three settings on the Nest.  Heat Only == Cool Only == Heat Cool.  I have several customers on the H/C setting during these shoulder seasons.  It does that.  Not as sophisticated  as your description above. Effective, yes.

The best equipment for doing this "communicating" equipment.  I'm most familiar with Carrier Infinity series, but American Standard and Goodman offer similar control I believe.

Infinity can manage airflow and staging.  This allows it to adjust focus from removing sensible to removing latent.  If you really want air conditioning to have that "doesn't feel like air conditioning, just feels comfortable" outcome, you need to go this direction.  

Some Inverter Driven Mini-Splits can operate using the same principals.  

If you can't afford/justify changing equipment, you can adjust certain set up features of Ecobee and Continuous commissioning/ watching performance.  http://bit.ly/4ecobeethermostats.

Ted,  Without using name brands or proprietary terms,  how would you suggest specifying 'communicating equipment'?  

Very easy to spec 'Builder's Grade'  80 AFUE, single speed draft induced gas fired furnace with 13 SEER AC.  Or Upgrade to 90+ AFUE sealed combustion with 15 SEER or Upgrade 2 to 94+ sealed combustion with 16+ SEER AC.  and so on.

I could use an Upgrade Level III in my arsenal.

Hi John,

That is stretching me a fair distance outside my expertise.  Let me convey the idea, then you can design to it:

Imagine you have a milk jug with a few holes in it.  You want to keep it 1/2 full of water and place it under a tap.  Your design strategy is to keep it as close to 1/2 full without ever shutting the tap off.  Shut the tap off and you get a big penalty.  Turn the tap on like a fire hose, you get a big penalty.  

The water is proxy for thermal comfort and fresh air.  A modulating boiler outdoor reset on steroids. 

So your thermostat needs to know how to manage the throttle on a LOT of things.  BTU management AND adjusting airflow, and in the really sweet equipment, compressor adjusts and exv adjusts refrigerant efficiency. 

NOW we have to design so airflow stays above .08 and below .4-.5 if you really want optimal distribution, distribution cost, and even comfort.  Too high, costly and noisy.  Rare occasion too low, trickling/uneven distribution.  So we test ESP on existing equipment and hope we can bring that typically terrible number into line when we drastically down size the replacement.

Since you are constantly and cheaply (fans laws) mixing air, why not inject fresh, latent managed air into that btu circulation?  Sure, why not?  http://bit.ly/VentDehum 

All temps stay in line - Latent/Sensible/Mean Radiant.  Super efficient.  Super comfortable.  

Comfort - http://bit.ly/comfortcalculator

Super Efficient - http://bit.ly/rickchitwood

Hope that helps.  Let me know if it looks like Greek instead of English...

Some of the higher end Emerson thermostats do this. It's called "cool savings" and adjusts the setpoint automatically based on system run time. The more the system runs, the greater the offset.

http://hvac-talk.com/vbb/attachment.php?attachmentid=200842&d=1...

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Kurt Shafer replied to Tom Conlon's discussion Whole House Fans - Love 'Em or Not?
"Graham, what "large fan" are you referring to?  I am fascinated by your comment…"
2 hours ago
Profile IconTom Mallard, Eugene Swier and 2 other members joined Hal Skinner's group
Thumbnail

Radiant Control Coatings

A group where people who work with radiant barrier coatings can let others know all of their uses.See More
4 hours ago
Graham Irwin replied to Tom Conlon's discussion Whole House Fans - Love 'Em or Not?
"I think it is important to check the energy consumption of such a large fan, even assuming it can…"
4 hours ago
Hal Skinner added a discussion to the group Radiant Control Coatings
Thumbnail

Rooftop A/C units and exposed ductwork

Lets start a discussion about rooftop A/C units and exposed ductwork. The worst place to put a…See More
5 hours ago
Richard Beyer posted discussions
6 hours ago
Brandon Walton replied to Brandon Walton's discussion EFAZ and APS Hosting Huge Welcome Party!!
6 hours ago
Brandon Walton shared their discussion on Facebook
6 hours ago
Brandon Walton posted a discussion

EFAZ and APS Hosting Huge Welcome Party!!

If your in Arizona on August 20th, stop on by and check it out!APS Home Performance Program Q&A…See More
6 hours ago
Brandon Walton posted an event

Efficiency First AZ is Hosting Huge Meeting August 20th! at Rennick's Restaurant in the Hilton Phoenix Airport Hotel

August 20, 2014 from 5:30pm to 7pm
APS Home Performance Program Q&A w/new leader Maggie Gibbs!Join Efficiency First Arizona (EFAZ)…See More
6 hours ago
Dennis Heidner replied to Jamie Kaye's discussion Flickering LED lights
""CFLs produce light by using electricity to instigate a chemical recation between mercury…"
7 hours ago
Richard Beyer joined Michael Stuart's group
Thumbnail

INFRARED THERMOGRAPHY USERS

This group is dedicated to knowledge sharing and discussion of infrared thermography for building…See More
7 hours ago
Profile IconTomás León, Tauran Ivall, Alex Burnham and 1 more joined Home Energy Pros
8 hours ago

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service