HeatManager vs Reset - with wood stove

Farmer_2

Thermostat was fine as a control until I started using the wood stove in the main living area. This is also where the thermostat is which I keep at 65. When running the stove during the day the room temp can vary widely from 65 to 73F. It is a small unit and I just let it die down at night.

I would like to keep some warm water flowing in the remote rooms. They cool down below 65 when the stove is running and the boiler doesn't fire.

So I want to add some other type of boiler control with constant circulation. System is low mass non-condensing EK boiler, radiators (no TRVs), piped P/S.

The Tekmar 256 and the Beckett HeatManager are about the same price. Or I could spend another $100 for the 260. As I understand it, Tekmar would switch via TT terminals instead of interrupting line voltage, have LCD, outdoor reset sensor, more adjustments.

But the HeatManager seems like it might better as the indoor conditions are changing more than the outdoor conditions.

Recomendations? Thanks.

hydronicsmike

Definitely Reset

And I would use Mixing for full Outdoor Reset, like a 361 with Variable Speed Injection Mixing, or a 360 if you prefer to use a Mixing Valve.

The temperature swings are caused because the water temperature delivered is too high. Not sure how the Heat Manager would help. To my knowlege, the Heat Manager doesn't reset the water temp, it adjusts the differential on the boiler to minimize short cycling.

If you want to talk, call me at 250-545-7749, Ext. 214.

Regards,

Mike

www.tekmarcontrols.com

Ron Schroeder_4

Hi farmer,

Definitely reset is my vote too but I would also suggest putting the room with the wood stove on it's own zone.

Question for Mike, wouldn't this be a good application for an indoor sensor on a 260 for the main zone and a t-stat to control the zone in the room with the stove? Wouldn't that configuration compensate for the stove heat that gets outside of the room with the stove?

Ron

hydronicsmike

sounds good to me, but....

Only if the rest of the building is a single Zone. I always get a bit nervous when an indoor Sensor is used and then other thermostats to lower the temp in other zones, as the water temp delivered is always based on that Indoor sensor. I have had jobs where people used an Indoor Sensor and then thermostats to lower the temp in other Rooms with Setback, where those Rooms could not recover because the Indoor sensor pushed the water temp down low.

Maybe in bedrooms it is a different story.

In either case though, with or without Indoor Sensor, I would still like to use a Mixing Control instead. I find it very important for the Boiler Return Protection and increased Comfort Level by being able to lower the supply water temperature below a Boilers Minimum. He already has complaint about Temperature swings in the Space and to give him anything less, may or may not make him happy. Why take the chance. I like what the TACO guys use as s slogan, "DO IT ONCE, DO IT RIGHT".

The man is unhappy. To make him less unhappy, doesn't cut it. You make him comfortable and he will be as happy as he can be about his Heating System and he will be your next referral.

If you really want to go wild on this job, put in a Storage Tank as well. He will burn less Wood and only stoke it every couple of days rather than having to make a fire every day.

Hope this helps and answers your question.

Best Regards,

Mike

Ron Schroeder_4

Hi Mike,

With both Outdoor and Indoor sensors, how much above the calculate boiler temperature curve based on the OUTDOOR Sensor will the INDOOR Sensor move the curve?

Also, how much will Occupied/Unoccupied adjust the curve?

Thanks,

Ron

hydronicsmike

Curve Shift

Ron, I am sure you are well informed about the way it works, but in case others read this as well, the Control comes up with a Target Water Temperature based on Outdoor Condition at first, where the Indoor Sensor then takes the Heating Curve and then fine tunes it based on Indoor condition. The fine tuning is done by taking the Heating Curve and shifting it in parallel up or down depending on whether the Indoor Temperature is above or below the desired Setpoint. If Indoor is below desired, Curve is shifted up and if it is above the desired temp, the Heating Curve is shifted down. Automatic Adjustment capability is a Parallel Shift of +10°F and -30°F of original Curve.

OCC / UnOCC in Controls are either the Starting point of the Heating Curve in either szenario or Indoor Temp if Indoor Sensor is used.

Hope this answers your question. If not, please feel free to call me at any time. 250-545-7749, Ext. 214.

Best Regards,

www.tekmarcontrols.com




Mike

Leo

If I understand you right you have an Energy Kinetics System 2000. If this is what you do have they boast efficiency based on their Energy Manager, I would check with them to be sure of compatbility.

Leo

todd s

I agree Leo

The system 2000 control doesn't allow there to be any temperature left in the boiler to "economize" with the heat manager. I don't think it will be easy to add either type of control with EK or they would be selling it along with all the other options in their catalog.

Ron Schroeder_4

Hi Farmer,

You have a problem that neither Reset or the HeatManager will fix. For comfort and efficiency in general, the outdoor reset solution is better than the HeatManager but neither will solve the problem of the rest of the house cooling off when you use the wood stove.

To solve the problem of the rest of the house getting too cold when the wood stove is run, you have to put that room on it's own zone with it's own thermostat and move the thermostat for the rest of the house to someplace where it doesn't see the heat from the wood stove.

Ron