intelligent thermostat...not so intelligent

GP

Hey guys, thanks for the earlier responses.

I've learned there are thermostats on the market that work for my situation - atleast they sorta work.

My dilema is I'm running the heating system only 1ce per week (every Sunday morning). In order for these intelligent thermostats to work, they have to learn from the previous day(s) or week(s). But what just dawned on me is in Chicago, I can have a temp fluctuation of 10-20 degrees in a week's time.

So, if one Sunday it's 30 degrees out, a week later it could be well below freezing. Therefore, the not so smart thermostat will not realize this, and I'm going to have a church full of cold people wanting to hang me.

So, I think I'm going to forget this idea completely and just buy a cheap programable control - The day before, I'll just take the weather report into consideration and program it accordingly. UNLESS SOMEONE CAN TELL ME there's a thermostat out there that takes outside temps into consideration. Please speak up!

- Notice, the Honeywell Outside Temperature sensor does nothing more than display the outside temp. I learned it does NOT take the temp reading into it's fancy algorithm.

(If there's not some software out there to run on a stand alone PC that controls a thermostat, Man - I really did miss my boat. What a simple computer program this would be to write! (assuming I knew how to write programs)). I'd even connect it to the internet to get the weather report to calculate operating time!

Take care,
Gene.

BillW@honeywell

I never implied...

that the outside sensor did anythng but display the outside temperature. It is strictly optional. Variablity of temperatures was taken into considertaion when the system was developed, so I don't think you'd have a problem, and besides, you can disable the program with one keystroke.

Uni R

Tekmar

Have you checked TekmarControls.com? I think that some of the outdoor temperature reset controllers in the 300 series are adaptive and can handle a Sunday only event. (370 + 031 Timer)

Dale

Why not

Why not just buy a 7 day programmable and set it for 40 degrees or whatever is lowest min temp or so every day but sunday where you set it for what you want. If you don't have any pipes that might freeze you could get a 7 day time clock from the electronics suppliers or for real comfort a smart panel that feeds power the the heating unit and you call it on the phone to turn on furnace or lights or whatever you want.

Mike Murray

> in the 300 series are adaptive and can handle a

> Sunday only event. (370 + 031 Timer)



I was thinking that too. I just bought another 150 today and this reminded me of this thread. What about a simple reset curve (like the basic 150 can do) and use it with an ordinary programmable t-stat. Just program the thermostat so every day is above freezing except nice and warm for Sundays and let the Tekmar decide what the operating temp should be.
Two sensors for the Tekmar, one outdoor and one on the boiler. henh?

(I didn't think this fully through but it might be a tangent worth pursuing.)

Mike (not that Mike, another one)

GP

I never implied...

Right, I knew you didn't. It was my ignorance. I assumed an outside sensor would be part of the calculations of the intelligent thermostat. (I'm not in the business. I"m learning this as I go.) Thanks, Gene.

Floyd_5

Gene, your getting all worked up..

about nothing.... the bottom line is that at any rate you need to make sure that you warm the church up long enough in adavnce to warm up the mass of the building, ie. pews, walls. etc...and not just the air..... if you wait too long to turn the heat up you may have the air temps to 70 or what ever in the morning but the mass of the building may still be in the 50's!!!! We rave here often of the benifits of radiant heating, however in this case the reverse of that is what happens when you have the air temps. warm aand the walls and such are still cold.... they will still be sucking all the heat from your body and you will still "feel" cool.
This is especially noticeable with a building that has very thick stone walls that retain the cold for long periods of time.

I have used the Honeywell 7300 t-stat for years and I have it so that it goes to setpoint by midnite of Sat. night and have had no trouble with that. That t-stat will keep track of run times even in the setback mode and will start it's recovery accordingly.

You may have to play with the tme that you need to have it come to setpoint... but I think your making a mountain out of a mole hill here.....

hydronicsmike

Gene

I think you may have two options available.

Cheapest:

Use a thermostat like the tekmar 510 that has an 'Early Start' Feature, which means the heating zone is turned on a certain amount of time earlier (based on previous recovery rates) in order to have the air temperature at your desired temperature by the time the people arrive.

You are absolutely right. The only very exact way for 'optimum' recovery would be if one would take the current outdoor condition in consideration. A building recovers quicker when the outdoor temperature is warmer, rather than cooler.

The 510 (or the Honeywell Thermostat you have) will most likely do the job for you. If you're overly concerned, why not just bring on the system 2 or 3 hours ahead of time, period? Does it really matter if we are bang on with the recovery time? Or does it matter more that the people are comfortable by the time they arrive? You are still setting the system back for 6 days out of 7. If the temperature is up for 6, rather than 4 hours that day, do we really lose that much?

Better option:

Use a 300 Series Mixing Control with an Indoor Sensor (as suggested by 'other' Mike) and a timer for recovery. Then we could recover based on outdoor and indoor temperature. This could reduce the recovery time, but you'd still have to improvise by setting your timer to come out of the setback period earlier than desired.

Best Option:

Use a 370 (as suggested as well), or a digital Zone Control like the 369 that has an "Optimum Start" Feature. With those, the controls would be able to determine how much sooner the zone needs to come out of setback based on the Outdoor and Indoor Condition and you simply tell it at what time you'd like to have your zone recovered by.
This option will cost you the most, but as always, you'll always get what you pay for. It's the bang for the buck.

I hope this helps.

Mike

hydronicsmike

Mike...

...I think you may have the numbers mixed up. The 150 is a setpoint, not a reset control. I am sure you're thinking 260, right?

Great suggestion with the 370.

Mike (another other)