Anticipator setting question?

wrxz24

I have a triangle tube 110 that has one finned baseboard zone wired directly to the trimax board. The circulator is a taco 007 and the tstat is a honeywell t87.



My question is this, what anticipator setting should I set the tstat to? The i/o of the tt 110 says to set it to .2 but I have read that if you are using a circulator in baseboard applications, set the anticipator to the amp draw of the pump.



"For hydronic fin tube radiation, set the anticipator to match the amp draw of the zone valve or zone pump. That will give you six cph, which means that the heat will come on (if it’s needed) six times an hour or every 10 minutes. For cast iron radiators and infloor radiant, multiply the amp draw of the load by 1.2. That will give you three cph, or the heat on every 20 minutes. "



"The bigger the numbers on the anticipator, even though they are merely decimals, the longer the cycle. That means the heat comes on less often, but is on longer. It also means greater temperature swings and less comfort. So setting the anticipator at one extreme end or the other will get you either rapid cycling or big temperature swings — neither desirable."



<a href="http://m.contractormag.com/fey/mercury-bulb-thermostat-myths">http://m.contractormag.com/fey/mercury-bulb-thermostat-myths</a>



Thanks for any and all help.

Zman

Amp Draw

I believe that Carol meant "zone valve or zone pump relay". Since the circulator is on a completely separate circuit from the thermostat, the amp draw of the circulator is not relevant. If Triangle Tube says .2, That is the draw of the relay on the internal board, I would go with that.

Carl

wrxz24

Thats what I thought but

Wanted to make sure. You came to the rescue again Carl of course the settng n my tstat wasn't at .2, it was on .6.

carl, an recommendations for a tstat? I would think a tstat with the least amount of differential would be the best. Is there a tstat that will run heat cycles when the temp already matches the tstat setting? I think that would be perfect for a mod/con boiler.

Zman

Anticipator

My understanding is that the type of anticipator you have was primarily designed to reduce overshooting the set point temp on older systems. With non outdoor reset fixed temp boilers, it was pretty common for the radiators to heat up more quickly than the t-stat could react. The anticipator helped with the problem. The cycles per hour is secondary to the main function.

With outdoor reset, overshooting is less of a problem. Modern boilers also do a better job of managing cycle lengths.

The best t-stats on the market today are using indoor feedback to prevent overshoot. Tekmar systems are using indoor feedback in conjunction with outdoor reset. They also learn from previous overshoot events and antcipate by reducing water temps.

Carl

wrxz24

Any particular tekmar

you recommend?

How about this one? Someone had posted this one in another thread.



http://www.pexsupply.com/Honeywell-TB6980A1007-ZonePRO-Floating-Thermostat



Or this one?

http://www.pexsupply.com/Honeywell-TB7980A1006-ZonePRO-Modulating-Thermostat

SWEI

A tstat that will run heat cycles when the temp already matches the tstat setting

A stat with a proportional output paired with a proportional zone valve will do this.  The mechanical version is called a TRV.  The electronic version is  unfortunately quite rare in residential systems.  When using ODR with conventional on/off thermostats, it is necessary to shift the curve several degrees above optimal in order to give an on/off zone valve (or pump) sufficient authority.  The result is a slow cycling over and under the setpoint rather than constant temperature like you get with a TRV.

Zman

Tekmar

Most of my Tekmar experience is with full TN4 controls.

Many of the TN4 stats will work as stand alone units.

The honeywell units you are looking at are 0-10 VDC units designed for variable frequency valves.

I was thinking of on/off model that is capable of pulse width modulation.It  would  be used with a standard zone valve.

SWEI may be going a slightly different direction. I am not familiar with the product he speaks of. He is quite good, I am interested in where he is heading.

Carl

SWEI

Tekmar makes nice stuff

and it does work quite well with hydronic heat.  The new(ish) TN2 series are a bit less expensive than a full TN4 setup, and can utilize existing 2-wire thermostat cable (often saves the day on retrofits.)  They still have a TN4 bus, so you can add pretty much anything you want to them -- but for a four zone system you can usually get away with just the one box.



My issue is the on/off nature of zone valves themselves.  Belimo CCVs come in sizes with Cv's ranging from 0.3 to 400 and actuators for pretty much any kind of control signal available.  In smaller sizes, they cost about the same as a good zone valve does.  The problem is a lack of off-the-shelf proportional controls suited to small systems.  A small DDC controller costs less than what Tekmar charges for their boxes and offers near-infinite flexibility, but is not something I can easily have someone else commission in the field.  I'm currently looking for ways around that.



Those Honeywell stats are some of the very few with proportional output.  They can be used to control a CCV or other proportional valve.  They are optimized for fan coils and the PI coefficients are fixed; I'm just not sure how those will interact with a high mass radiant system.

wrxz24

I have a tstat that

Controls my slab zones made by wisbo that has pulse width modulation

http://www.pexsupply.com/Wirsbo-Uponor-A3030101-Wirsbo-Radiant-Thermostat-WT-1-Heat-Only-Two-wire-2063000-p



Would this work for baseboard heat applications too?



I was thinking of upgrading that tstat with one with a slab sesor , tekmar 519. What do you guys think? Swap out wisbo with this

http://www.pexsupply.com/Tekmar-519-Thermostat-519-One-Stage-Heat-Includes-Slab-Sensor-518-079

And take the wisbo and put that upstairs for the baseboard heat?

Zman

Wirsbo

The t-stat you have, is specifically designed to prevent overshoots in radiant systems. It pulse width modulates as it approaches the setpoint temp. I don't think it will work well in a baseboard zone.

With the tekmar stuff, I would either do a full setup or don't bother.

If you are gathering indoor temp, outdoor temp and slab temp readings, you really want one device to be taking all the date and deciding what to do with it.  I see the different devices competing with each other if you don't.

Carl

wrxz24

I like the idea of a slab sensor

In my situation due to the fact of solar gain. If there was a way to start warming the slab before the tstat calls for heat, that would prevent getting up in the morning with the temp at 68 and not 66.

But back on the original question. Carl, can you tell me about the 1.4 multiplier (a number that honeywell researched?)for the anticipator setting for high efficiency boilers.

http://www.heatinghelp.com/forum-thread/78011/anticipator-settings

If i take the amp draw of the tt 110 which is .2 and multiply it by 1.4, that gives me .28. Is that what I set the anticipator to? I think that will allow the tstat to think the room is at temp faster and the allow my boiler to run on the low curve setting when all zones are calling at once.

Not sure if this way of thinking will work. I watched my boiler last night for a long time and when all 3 zones were calling the boiler set point was 145 for ch1 curve and the return was 108 due to the slab return temps. I went upstairs to check the tstat and it appeared that the tstat setting and temp display were the same, might have been slightly higher than the tstat setting, so I would assume that the call for heat would have ended but it was still calling the boiler to make 145 degree water.



So, i think i need to adjust the anticipator so the cycles are less?



Pete

SWEI

Morning overshoot

from solar gain can be mitigated in a couple of ways.  One is the slab sensor you mentioned, best if it is located where morning sunshine hits during winter.  Another is to locate the ODR sensor on the northeast corner of the building, or even the north end of the east wall for some locations.  Look for a spot the AM sunshine hits first on the house that is under an eave.