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: 362

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

Paul Haasz joined Evan Mills's group
Thumbnail

Home Energy Ratings

Calculating them; visualizing them; explaining them; selling them .... there is a lot to discuss…See More
8 hours ago
Paul Haasz joined James Sayers's group
Thumbnail

Marketing Energy Efficiency

Sharing ideas, tools and examples of promoting energy efficiency to consumersSee More
8 hours ago
Paul Haasz joined allen p tanner's group
Thumbnail

Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
8 hours ago
Paul Haasz joined Leslie McDowell, BPI's group
Thumbnail

Building Performance Institute (BPI)

BPI is the nation's premier standards development, quality assurance and credentialing organization…See More
8 hours ago
Paul Haasz joined Sean Lintow Sr's group
Thumbnail

Best Practices (Residential)

Best Building, Retrofitting, or even Auditing Practices - what are they, what should change, what…See More
8 hours ago
Profile IconPerry Hurtt, charles michael durishin, Robert Lewis and 7 more joined Home Energy Pros
8 hours ago
Joe Konopacki posted an event

Duct & Envelope Tightness (DET) Verifier at Temperature Equipment Corporation

May 8, 2015 from 8:30am to 4:30pm
The Duct & Envelope Tightness Certification (DET) was designed by the Illinois Association of…See More
15 hours ago
Paul Raymer posted a blog post

Shades of Gray in Residential Construction Morality

I was called in to perform a last minute duct test for a modular home builder.  He was all in a…See More
18 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service