Summer/Fall Upgrade Suggestions

Brent H.

Greetings,



The heating system in my house consists of a Beckett burner with a New Yorker 76000 Net BTU hot water boiler with a tankless coil. The house was built in 1996 so the system is approx. 15 years old. Over the years, I've added a couple of zones as I've added onto the house and the house still heats fine through the New England winter here in Central Mass. (Proving that boilers are usually oversized) With the price of oil on the rise and no real/substantial drop expected, I'm wondering what improvements to my heating system may provide me with the most savings. Long term, I'm eventually hoping to install a triple pass boiler but am reluctanct to spend the money when my system is still running. So here are a few questions for you folks that work with these systems daily.



1) Any rough guesses on what savings might be expected with a new Buderus system(or similar)?

2) Would going to an indirect water heater so the furnace doesn't have to remain at such a high temperature gain me much? The one thing I like about this option is it would be reusable with a new boiler.

3) What would outdoor reset gain me? All heat is with baseboard heat.

4) How long do these New Yorker boilers last?



Thanks in advance for any suggestions or advice. I've enjoyed reading the forums here for a couple years and you folks have always been great with answering my questions.



-Brent

Charlie from wmass

yes you will save fuel dollars if you up grade

The questions start with how was your current boiler and baseboard sized? If set up for 180 or higher water temps to the baseboard it will work out pretty lean when you start dropping supply temps. this can be allowed for with the setting of the out door reset control. If the boiler was chosen due to the tankless it may be over sized. Indirect water heaters do save fuel, they also produce more hot water if properly installed. I find sometimes the extra hot water is enjoyed at the expense of any savings in fuel. This is not a bad thing just human nature. Delta T circulation can trim your electric bill as opposed to single speed. New Yorker boilers can last anywhere from 5 to 35 years. No way to really call it without seeing how it is maintained. 10 -25% is the range for savings If you add most of what you are suggesting properly.

Robert O'Brien

Answers

1. 30% range

2.  About 5-7 % assuming you can eliminate the boiler standby loss

3. I'd use an AquaSmart or similar rather than ODR in this type application. You need an indirect for this option and it should be good for another 7-10%



4. However long it lasts,you're using 30 % more than you should. You'd be better off if it died tomorrow,the longer it last the more it costs!

Brent H.

Indirect Hot Water Tank

Thanks for the feedback.



If I should decide to get an indirect hot water tank, are there any that would last longer since I do have a water softener?

Robert_25

"it depends"

Brent, how much fuel do you burn on an average year?  What are the current aquastat settings?  Does the tankless coil meet your hot water requirements?  A new boiler will be more efficient, but there might be some things you can do to ease the pain until you are ready for a boiler swap. 



It is good that you have a water softener...it will help maintain the performance of any water heater you chose.  Superstor and Triangle Tube have a good reputation in my area, but everyone has their favorites. 

Brent H.

Followup....

Hi guys,



Thanks for the information. I checked with my oil supplier and I burn approximately 1100 gallons a year. (Maybe that's why my bank account doesn't seem to go up in the winter.) The tankless seems to supply enough hot water at the moment but as my girls get older I tend to think it will become an issue.

If I were to go with a Buderus boiler, any suggestions on the best burner? There are plenty of service companies in the area so I'm sure service won't be an issue no matter which burner I get. Also, do any of the burner options allow for a outside cumbustion air connection when venting with a traditional masonry chimney? My current Becket has an outside air kit installed on it.



Many thanks.

meplumber

I prefer Riello on the Buderus.

They have a DV model that has a combustion air kit pre-installed.  It is for direct vent applicances, but I have used it on chimney vent boilers with combustion air concerns.



Good Luck.  thanks for the update.

Brent H.

Efficiency Gain/Lost

Is there any noticable efficiency loss or gain by using outside combustion air? Especially in the winter when it is cold.

Thanks.

Jean-David Beyer

Professionals may know the answer.

It is very complicated, it seems to me. With race car engines, it is important to have the combustion air as cold as possible, because what they are interested in is volumetric efficiency. They want as much power and torque as they can get, and do not care how much fuel they use. Any heat they generate, other than that used to push the pistons down, is wasted and must be disposed of.



For a furnace or boiler for home heating, it is very different. Here, it is the heat that is wanted, and any heat that goes up the chimney is wasted. Furthermore, any heated combustion air from the heated space is wasted too, as cold air has to come in from outside (cold) to replace it. So taking combustion air from the heated space is a waste. Now I do not know if you can get more heat out of a gallon of fuel oil or a therm of gas if the combustion air is warm or cold. Warm is probably better. (Consider combustion air of 225F, for example. If you had the right heat exchanger, you would not need any fuel at all to heat the house.) If the combustion air is extremely cold, that air would have to be heated more by the fire to get any particular temperature in the firebox or heat exchanger. Furthermore, any air taken in by the burner that was not used to burn the fuel would just carry heat out of the boiler or furnace out the exhaust, and that heat would be wasted too. My guess is that the way these issues balance out depends a lot on the individual system in question. As usual, it depends.



My W-M Ultra takes its combustion air from outside and it goes into the sealed boiler unit. The main thing in there is the heat exchanger that contains the burner inside of it. This is not insulated. So any heat that leaks out of the heat exchanger heats the combustion air. I have not put a thermocouple in the box to measure the combustion air as it goes into the burner, but except for when heating domestic hot water, the heat exchanger would not exceed the supply water to the system, so it is at most 135F when it is 14F below the design temperature. So if heating the combustion air is a good thing, I should put an air-to-air heat exchanger between the exhaust and the intake pipe. Of course, if there were any flow resistance in that exchanger, everything would need to be recalibrated. Also, I do not know about codes, and doing this might violate one. I am not going to do this.

Robert O'Brien

Outside air

Each gallon of oil burned needs approx 2000 cu/ft of air. Where does it come from? if the boiler is within the envelope of the home,it comes from the home increasing infiltration!  Outside combustion isolates the appliance from the home,allowing it to be tightened up w/o regard for combustion air supply,makes the burner quieter and increases eff from 1-5% from reduced infiltration.

Brent H.

Interesting Perspective....

Robert,

Very interesting perspective, I never thought about it that way.

If I go with a Riello and want to use outside air, would it need to be a BF3 burner? Is it a valid configuration with the Buderus to use a direct vent burner with a traditional chimney?



Many thanks,

 

carl_nh

Chimney with Buderus

Brent,

We installed a G125-21BE (smallest unit) in Feb 09 in our 2800SF cape in NH with heat loss calculated at 65-70K BTU and the Buderus ST160 stacked tank below the boiler. We have 3 zones plus the DHW. Air makeup is external and it is connected to the central chimney. We do get condensation in the fall and spring for about 2-3 weeks (when temp is 45-50* outside) but this is a only a temporary condition.

The old pin boiler and tankless DHW was consuming 900 gal annually we now are using 500 gal annually.

If you have an external chimney you will need to install a SST liner due to the low exhaust temps. You can also direct vent this with PVC as an option.

The installed cost was $2K more than a comparable "regular" boiler and separate DHW tank which is offest by the $1500 Fed credit on the G125BE as it is 90.7% efficient. I have seen this as well and the blue flame provides such complete combustion there is little residue in the boiler after 6 months.

The indirect stacked water tank (ST160) provides 42 gal of storage and looses about 8-10* over the day and that along with the 2107 controller is about the best system that I have seen on the market.

Brent H.

Buderus\Riello Questions

Greetings,



So I think I'm going to bite the bullet and replace my current system with a Buderus system including the Logamatic. I'm leaning toward the Riello burner but have read a few posts about people having issues with them running right when configured for outside makeup air and the weather is cold. Any guidance would be appreciated.



Also, I'm debating whether to go with a 40 gallon or 60 gallon domestic indirect. I don't need the capacity right now since my 2 daughters are under 5 years old. However, in a few years it might be useful. Does anyone have a guess at the additional oil usage if I go with 60 instead of 40 gallons?



Many thanks.



-Brent

lchmb

Domestic

Brent how many shower's/tubs do you have in your home? Hot tubs? Anything special? Unless you have something special I would go with the 40 gal. (lt 160) and add a mixing valve. Run the tank at 150 degree's and mix it out to 120. Btw, if you look at the Buderus G125 (you gain the tax credit) it has a Buderus burner on it and they recommend any service be done by a tech who has attended their class on the unit. It is a nice unit...

Brent H.

Followup

My house has 3 full baths(1 shower & 2 tubs) and no hot tubs. Nothing too special. I doubt all 3 baths could be used at the same time since I'm on a well and don't think my pump could supply them all at once. My installer likes the Weil-McLain indirects and it looks like their model 60 is actually 46 gallons.

Although the G125 looks interesting, I'll probably stick with the G115.

lchmb

either

Both are excellent units. There are of course other boiler's out there that are 3 pass....As far as the indirect, putting the tank under the boiler clears up alot of room..just a thought for you..;)

carl_nh

Rebate

Hi Brent,

The G115 is good but the G125 $1500 rebate from Govt. pays for the upgrade plus you get 90% eff over the long term save more on fuel let alone the consistent efficiency of the blue flame units.

I also considered the G115 with the Logimatic, and tiger loop - the total was about $800-900 less than the G125.

The stacked setup with the boiler on top of the HW tank is space saving and also makes it easy to service and clean when needed. and its a very short run to/from the HW tank.

Unless you need to line your chimney by going to the G125 the ROI is definitely better - I calculated with the G125 vs the old boiler will be 6 years.

For the G115 the initial lower cost will be consumed in fuel.

Robert O'Brien

Carl NH

There is no $1500 rebate as of 1/1/2011,it's $150 for 2011

Brent H.

Riello with Outside Air

Thanks for the feedback. At this point, I'm not sold on condensing oil burner/boilers and am going to stick with the G115.



Does anyone have any feedback on reliability in the cold weather of the Riello burner when used with outside makeup air?



Thanks.

R Mannino

This One was Clean After A Winter of Service

with outside air on Long Island

Brent H.

Buderus Cold Start with Logamatic

I'm planning on going with the G115 with the Logamatic controller. Is it possible to have this setup for cold start or is the boiler always warm when used with the Logamatic. I understand that the Logamatic will lower the temperature of the boiler as the outside temperature becomes warmer.



Thanks.

R Mannino

The Logamatic

determines when to fire the burner. The boiler will stay warm when below the WWSD temperature setting. The closer the curve is to the actual heating needs of the home the lower the actual water temperature of the boiler will be.

Brent H.

Logamatic with non-Buderus Indirect

I've seen a few people comment on issues when the Logamatic is used with a non-Buderus indrect. Can anyoune elaborate on this?



Thanks.

R Mannino

Logamatic DHW

The Logamatic uses a sensor as opposed to an aquastat. It usually goes into the well the aquastat would. Some indirects don't have a well, you would need to "silver tape" the sensor to the surface of the tank under the insulation.

Brent H.

Weil-McLain with Logamatic

Any idea if the Weil-McLain indirects will work properly with the Logamatic?



Thanks.

lchmb

Brent

Depends on which tank you have but I believe they are tank within tank with their own control so probably not. You could wire it as another standard heat zone but you would lose outdoor reset...You need a tank that you can either put the sensor against the domestic water tank or with a well for the sensor to go into...



unless someone has a trick for that..I have never been told of one..

Brent H.

Replace W-M Control

Is there any reason that the Weil-McLain control can't be removed and the Buderus sensor put in the well?

lchmb

It

is not in a well...not sure if you could try and get the sensor in, against the tank.  in it's place or not..never had one I needed to...

Brent H.

Drywell Replacement Kit

Looking at the manual online, Weil-McLain sells a drywell replacement kit for most of their indirects. Not sure if their aquastat can be removed and replaced with the Buderus sensor.

Mac_R

Buderus Logamatic

DO NOT!!!! use any indirect other than a Buderus indirect with a 2107 control.  Trust me you WILL have problems.  If you are going to use a 2107 (I highly recommend you do with a Buderus)  Use the BFU module and put the main living space on constant circulation.  The comfort levels in the home will be like anything you have ever had.  Also use a Taco Delta T pump.  Not a Grundfoss three speed or a 007.  

Brent H.

The results....

Greetings,



Thanks for all the information and input you've provided. A couple weeks ago, I spent three days working with my contractor(that was part of the deal....I was his slave for 3 days) and we installed the new system. I ended up going with a 3 section Buderus and a 60 gallon indirect. Everything is working well so far. I performed a bit of a test the other night when it dropped down to 30 degrees. I ran all the zones at 68 degrees for 12 hours to see how many hours the burner would run. The next morning, when I checked the hours meter on the Logomatic, it had only run for 4 hours. That seems pretty good since the heat loss I did used a 70 degree indoor temperature and 0 degree outdoor. Since the system only ran for 4 hours with a 40 degree difference between in/out it should run for 8 out of 12 hours at design temp. which leaves me a bit of headroom. Not terribly scientific but it shows my heatloss wasn't way off.



One quick question for you oil guys.... I used a thermocouple to check the temperature of the flue gases and it showed about 405 degrees. Is that too high? I believe the spec's call for 350.



Thanks again. I've attached a picture below of the system



-Brent

R Mannino

What Type of Chimney Do You Have?

405 is not bad if you have a masonry chimney. It will keep condensation issues away.

The way the Logamatic fires the burner, the run times are reduced along with the stack temperature. I'd leave well enough alone.

Brent H.

Chimney

It is a masonry chimney but we installed a SS liner.

R Mannino

What Position

are the baffles in?

Brent H.

Baffles

Both baffles are in and in the fully closed position.

R Mannino

That's

pretty much it. Only other things left would be tuning adjustments at the burner and draft settings. I'm assuming that 405 number is at steady state operation.

Brent H.

Measurement Method

I tried it quickly again tonight. The boiler was at 135 when I hit the manual fire button on the Logamatic. I'm placing the thermocouple through the test hole in the flue pipe that's approx. 12" up from the elbox that is attached directly to the back of the boiler. I tried it again tonight and the temperature in the flue had climbed up to 385 and the boiler reach 165 when I shut it off. If I had left it I believe it probably would have climbed up to 400. I assume I'm taking the measurement correctly. I only tried it the other night because I was curious and happen to have a meter/thermocouple to try it with.....

R Mannino

Your Boiler

isn't going to get to 165 too often, probably only on a DHW call. Most of the time the stack temperature will be much lower. Don't forget to subtract the ambient air temperature the burner is seeing to get the net stack temp, which is the one that really matters.