outdoor reset savings report

CC.Rob_2

Old system: 2+x oversized CI boiler, bang-bang, 180F (2003 Burnham Series2 206) no controls

New system: right-sized CI boiler (Burnham Revolution) with tekmar 260

Building: 2100sf, fin-tube throughout

Fuel use down by 23% (normalized for degree days). This under light loads for past 6 weeks.

A few other competing factors (7-8% could be due to better AFUE if you're into that), but in general, pretty neat.

Al Roethlisberger

It's a shame(sortof statistically speaking) that more than one "variable" changed in this scenario, as I'd really like to know how much the Tekmar helped.

I am looking into installing a Tekmar(256, I don't have integrated household hot water) myself after a recommendation here and am just very curious about the potential positive impact of that alone.

But that's very cool to hear about a 20%+ savings overall indeed.

If anyone has any other stats on just installing a Tekmar, that would be great to hear about as well.


Al

Unknown

don't have the number figures

Don't have the number figures. But you can see the result. Before, apt buillding without tekmar control on boilers, most of the windows are opened... After teakmar installed, all the windows are closed and no one complianing of over/under heating...

Unknown

Al Roethlisberger

Where does the Tekmar 256 place its boiler water ouput sensor?



That's excellent.

One question, I was reading the installation notes for the 256, and it looks like it piggybacks onto my existing boiler controls versus replacing them... which is fine if true.

But it obviously has a boiler sensor to measure the output water. My current electomechanical boiler controls hang directly off of the out boiler output piping to sense the water temp. The online install documents for the Tekmar don't show how their water temp sensor is attached. So I am wondering if you know if their sensor needs to be directly piped into the boiler output water flow(which would require a new fitting for me to install), or if it simply attaches to the outside of the pipe? The install docs aren't clear, and I don't have a photo of the sensor itself(they call it an 071 Boil Sensor).

Thanks
Al

ALH_4

071

The 071 supply sensor can be strapped onto the ouside of the pipe and covered with insulation. There is also the 070 outdoor sensor in the white plastic box. Your existing boiler demand (either from your zone valves or your pump relay) is wired into the 256 to tell it that there is a call for heat. The 256 then controls the output to the boiler based on the outdoor temperature and the temperature seen by the 071 on the supply pipe.

Rob_32

256

If you have a switching relay (e.g., a Taco), it might be simpler to upgrade the switching relay to a Taco EXP and add the Taco PC700 (which I believe has the guts of a tekmar 256?). Just thinking out loud.

As Andrew mentions, the boiler sensor is a strap on to the supply pipe. There's a doc on the 07x sensor series at tekmar showing the housings, specs, etc.

EJ hoffman

Tekmar 356

did a radiant job for a friend about 5 years ago. He called me up after gas prices skyrocketed here and asked me for ways to lower his gas bills. we changed to a 356 with injection mixing got rid of the buffer tank and had a 12% decrease in fuel bills weather adjusted.

realolman

I've been thinking about a similar thing

Putting a Tekmar on a burnham v74.

Al, I think I saw in another thread, you were considering a 260 because of features besides the DHW.

I have a tankless coil in my burnham that I quit using, but I might consider an indirect... or maybe even go back to the tankless if I ever get all this figured out to my satisfaction.

Anyway... could you use a 260 WITHOUT DHW with no problems?

And Al, I can't resist, being from western PA... I don't suppose anyone's ever asked you if you know "big Ben"?

GW

priceless

We've sold more smart systems this year than ever before; we're on a roll with panel rad conversions. 9 out of 10 companies around here just pitch the swap while we're throwing the whole enchilada.

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GW

adjust weather?

how do you do that please?

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Brad White_159

Tongue in Cheek, Gary? :P

If I take it as serious, he means that the fuel usage was corrected against the actual degree-days endured so that the therms burned were reduced to a common "per degree-day" basis. Otherwise a cold period and warm period could not be compared.

Al Roethlisberger

Adjusting weather, and Big Ben


... well, to adjust weather, I guess either you build a dome, or "adjust location" and move! =P

As far as relations to Ben, I think you may be the first to ever ask! *wink*

I'll give you my standard answer: "I probably am related, but don't know him."

After many inquiries, we usually just say, "...he's our cousin" which probably is relatively true *laugh*

What's really funny, to me anyway, is that he is from the Ohio Roethlisberger clan, but I am from the Pittsburgh Roethlisberger clan... which my brother and I represent the last of. So it's funny to us that Ben ended up the QB of the team my family grew up rooting for


But back to the subject:

Yes, I am considering the 260. The DHW feature is a waste for me, as my boiler doesn't currently have the configuration to support that use.

The only advantage I can see with the 260 for me would be:

1) Use of inside temp sensor to aid in calculations of heating curve

2) Direct control of circulator pump from the unit

#1 seems like a "win", but beyond the function of the occasional exercising of the pump during off seasons, I don't know that the 260 would operate my pump any better/differently than my electromechanical Honeywell aquastat does today.

I think the 260 might seem to offer some "investment protection" if I ever install DHW functionality, but I'm not so certain that by the time I did that(i.e. replace boiler in a decade) that there may be something better anyway.

So I'm still thinking on the 256 versus 260 issue.

Al