Logamatic w/ Hydro Air system

Rena Nicholson

Rena Nicholson

Logomatic with Hydro Air System

New to these boards.My question has to do with Logamatic also. I am in a brand new home with a very inefficient boiler. I am looking to change it to a Buderus but am confused as to whether or not a Logamaticwould help with efficiency. I have an approx 2500 sq ft home with a hydro-air system with 2 zones, each having its own air handler with a 75,000 BTU coil in each one. I have had many heating techs here to give me estimates and their opinions. One said I cant use the Logamatic because the air handlers wont kick on when the water goes below a certain temperature and that if it was "warmer" outside and the Logamatic determined the water should be less than 140 degrees, the air handlers would never turn on to provide heat. He also said it didnt make sense to run water through the air handlers at a lower temperature because it would take longer for the house to heat up and the blowers would have to run longer just to get the house up to temp. He continued to say that if the water was hotter we would heat the house up more quickly thereby being more efficient. I really need to get the real answer to this issue because as more time passes, more oil is being wasted and the heat the boiler is making is going right up the chimney.
On a side note, I was told the Buderus doesnt use the Riello burner with the automatic air gate. He said Buderus suggests using the Riello that has an open gate.... Please help in any way you can

THANKS!!!

bill nye_3

Hydro

The logamatic will work better with radiation but I have a system with hydro -air in my cousins house.

You will have to reset the reference point. The logomatic will manage the domestic hot water, it will provide some savings, and increase comfort.

I had/have hydro air in my house. (I don't use it currently I use radiant floor and radiant baseboard) The extremely hot water temps, 180°, were very uncomfortable. Especially near the end of the cycle when the thermostat was almost satisfied. I found it more comfortable with 140° water.

My cousin is on his second season with his. It is a large house, 4500 sq ft on three levels. He and his family are very comfortable, no complaints. I would do it.

kpc_12

Buderus is ...

a great product. I would not opt for the logamatic on a hydroair set up. Stay w/ the striaght set up. You will save money on that alone. What is in there now?
As to the Riello the Buderus package does not come w/ an Air gate...electric or hydrolic. ..just the fixed setting. less problems later...that being said I have a non stock riello on mine and it has an elestic air gate. 3 yrs and no issues.

bill nye_3

Hydro

The logamatic will work better with radiation but I have a system with hydro -air in my cousins house.

You will have to reset the reference point. The logomatic will manage the domestic hot water, it will provide some savings, and increase comfort.

I had/have hydro air in my house. (I don't use it currently I use radiant floor and radiant baseboard) The extremely hot water temps, 180°, were very uncomfortable. Especially near the end of the cycle when the thermostat was almost satisfied. I found it more comfortable with 140° water.

My cousin is on his second season with his. It is a large house, 4500 sq ft on three levels. He and his family are very comfortable, no complaints. I would do it.

The "air gate" Is an off-cycle damper. It closes when burner is off to prevent room air from entering through burner and going up chimney. It "may" realize a 1% saving - depending. There was trouble with a leaking seal in the hydraulic jack a few years ago. So, for the most part they were discontinued. Don't get lost on this, it is really not important.

Maybe you have some control issues? Do you operate cold start? Maintain high limit? I have seen some interesting control strategies. Most simply because the electrician wasn't sure how to wire it and the plumber wasn't sure either

Leo_9

Why do you say

Why do you feel you have a very inefficient boiler? What brand/model is it? In a brand new home you may have other issues going on. Is the duct work properly sized? Properly insulated and sealed? Filters clean?

I wouldn't be so quick to replace a brand new system. It is good to see you have come here for some info, what you received is limited at best.

Leo

Rena Nicholson

Thanks for the answers so far. I have a Vesta Steel boiler with a Beckett Burner. Hot water coil in the boiler. It is really a piece of junk. Every person that came in laughed when they saw it. One did an efficiency test. 450 degree temps in the flue.

Rena Nicholson

Science guy. My current boiler is set at 160/180 degree limits. Can you tell me how the logomatic works with controlling the hot water besides keeping it at the temperature I want? So far, I only understand how it works with the outdoor temperature sensor

Big Ed_4

Logamatic

A outdoor reset works great with hydro-air you just may need to increase the reference temperature depending on the coil size .

If a aqua stat is used to control the fan in heat mode all you need to do is drop down the setting.

The idea of the reset is to put the system is steady state.

Yes the Riello air gate is not recommended on the Buderus . I guess it is not needed..

Rena Nicholson

Rena Nicholson

Each air handler has a coil that is 75,000 BTU

bill nye_3

Paul

Hot water management. On a call for hot water your current control would go up to high limit {not with your coil, but if you had an indirect} and if the indirect got satisfied the boiler would be sitting there with 180° water you just paid to heat. The standby loss would be wasted up the chimney. Water you paid to heat for no real reason.

The logomatic would sense that it was nearing the set point in your water heater, it would stop the burner before the water heater was satisfied and try to purge the heat into your water heater.


The logomatic could provide priority for the water heater. It could be set to not operate at night or if you were away for the weekend. In the summer the burner could be off while you are not making hot water. Unlike your present boiler that stands by @ 160° all the time.

I know it does more, I don't know how to say it.been a long day

Leo_9

Has anyone

Paul,

People have laughed at your boiler and want to sell you a new one. As you have seen by the answers you are getting outdoor reset does work with hydro air so I question a lot of what those who have visited your site have said. Again, has anyone done a heat loss, made sure the duct work is sized properly, made sure it isn't leaking, and made sure it is insulated? A highly efficient boiler feeding a highly inefficient system will gain what?

Leo

Rena Nicholson

Nobody did a heat loss calculation and the guy I chose to replace it did give me many options, however, nothing would give me the efficiency of replacing it. He just feels the way he is wiring the boiler as a cold start application will be close to the efficiency of using the Logamatic. I really cant say he is right or wrong.
One who came was a family friend and not interested in selling me anything, but also felt the same way.
I believe all the duct work is fine because the A/C guys who did that part of the installation are top notch and all duct work is insulated.

Rena Nicholson

Hot water

Makes a lot of sense. So, the logomtic could be set to not turn the boiler on to heat the water even if the temperature is not where I want it? Would it then turn the system back on at a specified time or when I call for hot water?

Bruce Stevens_2

Not what he is saying

it will call to heat the hot water but at the end of the cycle it will shut the burner down earlier so that the last of the heat is purged from the boiler to the hot water maker, at least to the temp of the HWM and not be sitting at 180 and cooling off.

Leo_9

Really

He believes wiring the boiler "cold start" will be close to the efficiency of the logomatic. He knows nothing about the logomatic. It exercises the circulators in the off season, it runs all circulators to prevent a freeze up in the event of a burner fault. Not to mention the outdoor reset feature. It sounds like you have a steel boiler with a hot water coil. Now switching boilers you must be going to an indirect water heater. Just abandoning the coil and adding an indirect would have saved you close to what you will be saving with a Buderus with just a cold start control.
Even though a top notch company installed the duct work doesn't meanit was sized right. Who made the boiler choice? Did that person do the heat loss? You really have to look at the whole system.

Leo

Rena Nicholson

The builder put the boiler in and I believe the architect sized everything. I just cant believe I cant find someone who knows how to handle this for me. I almost chose a guy that was going to put in a system 2000, but I decided against it because I didnt want to have problems down the line trying to find someone to service it. That was the guy who told me I couldnt have the water temp below 140 degrees and that a logamatic wouldnt help. The guy I chose to do the install said he called the rep for Buderus and said the rep told him that he shouldnt use the logomatic with my system. I am going with the Buderus Indirect. He said it would be a fairly expensive job to just add an indirect because the way the boiler was set up and I felt if I was going to spend $4000 I probably should spend a few thousand more and get the whole thing done.What should I do at this point?

Rena Nicholson

I was referring to where he said it can turn off overnight. Sorry for the confusion.

joel_19

ducts!!!!!!

Have a true duct expert someone certified by Comfort Institute or NCI look at your duct system FIRST. I just tested a home where over 40% of the energy was being lost through the duct system. Fixing the duct system typically gives greater comfort and eff for less $$$$$. Plugging a Buderus into a bad duct system is like putting a Ferrari engine in a Yugo. You get a Yugo that sounds good but still stinks to drive.

bill nye_3

confusion

Sorry Paul, I should have said you could stop hot water production during setback period. The hot water is still available and 40 gallons, [example] is stored in your tank, but the boiler /burner won't produce more hotwater during night setback.

Gary Jansen_4

75,000 btu coil?

75,000 btu coil under what conditions? The output of any coil is based on both water side temperatures and flows, as well as air side cfm and pressure drop through the coil. A Logomatic may work well with your setup depending on the coil structure. A good heating contractor should have gotten the model number of the coil, as well as physical size, number of passes, coil fins per inch, etc., and computed output based on varying flows and water temperatures. A condensing boiler isn't a condensing boiler when it has to run above dew point to heat the house. A great man (I'll call him John Barba) once said DO THE MATH! If your contractors aren't, you will still have an inefficient system when it's all said and done. Good luck!

Rena Nicholson

DUCTS

Nobody in listed for NY on comfort institute. One guy listed on NCI. Maybe I will give him a call. WHat would actually be fixed on the duct system if it is all insulated?

don_185

The logomatic

The logomatic control would work great with hydro coil that
had a variable speed motor in the airhandler unit.

With a relay and a aquastat you can set it up to run low speed when the logomatic is lowering the water temps.

Example, with some boards with variable speed motor if, you had a call for heat and the stat energize the fan on heat
mode the motor would run at its lowest speed.I think its 200
cfms

Now if you were to have the same setup as above and the stat was still energizing the fan in heatmode to get it to
speed up the motor to its highest heat speed you would have to energize the emergency heat circuit to get it to ramp up
to high heat speed.

Just alittle more info to help you think out the box.

joel_19

ducts

Typical sins include.

1. Not enough returns like only a hall return upstairs.

2. Ductwork too small increasing static pressure lowering output.

3. ductwork in non conditioned spaces that is not sealed,regardless of if it insulated

Rena Nicholson

We definitely dont have enough returns! One on the first floor and we originally had one (in the hall) on the 2nd floor. We had them add another in the master bedroom.

Big Will

Its a toy

But I have hydro air in my house. I used the largest coils I could fit in the attic and doubled them. This allows me to use 120 deg water. This makes a condensing boiler possible and outdoor reset feasble. I will be adding radiant slab when we redo the floors next year so I hope to have a system that is all low temp. This dose mean 110 deg output air temps though. kinda like a heat pump but it does the job. On the ducting I would look for leakage more than insulation. A attic return with leakage and a filter grill in the house will really effect your system. Something as simple as a return air chase that was not properly finished can make or break a system.