Buderus GA 124/130 w/ logamatic control

Glenn Sossin_2

Agree with the estimated temps given here but I would look at using injection controls such as a Tekmar 356 in conjunction with the indoor outdoor reset function of what ever boiler you choose. Based on your post, at any given time, you will need 1 of three generalized temperatures, 170 + for the DWH and fancoils, and possibly 2 or more generalized supply temps( a high and Low) for the different floor coverings.

These temperatures are arrived at by doing a proper heatloss for each room, looking at the overall floor construction - taking into account the floor covering, and the insulation below. Typically, these calculations are done using a computer program.

Your heating contractor, should be able to provide you a detailed heatloss for each room (which you can verify) and the associated design requirements such as gpm, water temp,head loss,tube sizing and spacing - all dependent on the heat medium used and floor covering.

Most likely, based on the different floor coverings, you will have temperatures ranging from 100F to 160F. In theory, you would group like temperatures together and design a system to deliver them. A key point to understand here is that these temps represent what would be required to heat your to an indoor design temp (say 68F), for specified outdoor design temp (say 0F).

The delivered temperatures of the system can be controlled typically by one of three ways, a tempering valve, and injection control, or indoor/outdoor reset of the boiler. Using the indoor/outdoor reset function of the boiler is great if you only need one temp - say a constant circulation system - not the case for you. You have different floor coverings which by their very nature, will require different supply temps.

A tempering valve attempts to provide water at a fixed setting - regardless of outdoor temperature. It is a static device. It will try to provide what ever you set it at regardless if it is 15F or 55F outside. See the shortcoming here?

An injection control, would adjust the water temperature it sends out to the floor based (by controling the injection circulator and boiler firing requests) on a number of different factors, including outdoor temp, boiler water temp, secondary loop temp, rate of change in primary loop, secondary loop and outdoor temps. It is basically a computer chip that responds in real time to changing conditions - unlike the tempering valve that is static.

Injection will provide you the best possible comfort and fuel economies. In a perfect world, we would try to send only the necessary heat energy to the area requesting it. This is what an injection control would try to do.

There is no simple answer here, the piping and control system need to be designed to meet the requirements of your heating system. You need to provide floor covering information to your heating contractor. He inturn should provide an accurate heat loss to understand your system requirements and provide you the options for heating your home.

Keep asking questions - thats how you'll learn. The more you know, the better your final decision will be.

andy_21

Buderus 124 w/ logamatic R2107

Looking for a new boiler install for a multi temp. system & Domestic Hot water.
1st floor 1500 sq' radiant, 1/2 wood fl & 1/2 tile fl. w/ hydro air as back up.
2nd fl 1500 sq' hydro air primary heat & radiant @ 2 baths.
I was looking @ the Buderus GA124 w/ the logamatic control to take advantage of the outdoor reset feature.
One contractor said this would give me the mulit temps that I need for the different zones & another said it will only heat to 1 temp & that needs to be mixed down for the radiant. I looked up the control on the Buderus site but the info is kind of limited. Can anyone point me in the right direction. Located on LI ,NY. Thanks

Robert O'Brien

Is

the first floor radiant with the 2 different floor coverings designed to the same temp?

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andy_21

temps

The 1 st floor was designed for wood areas @ 130 supply /79 surface, the tile areas@ 110 supply/ 77 surface temp. Hydro coils @ 160-170.

andy_21

Thanks for the detailed info. But just to be sure, The Tekmar 356 control would be used in conjuction w/ the logamatic control or in place of it?
With the multi temp needs I have, is this system way I should be heading without creating an very involved system.

Mad Dog!!!!!!!!

Hi Andy...Why wouldn't you be looking at the Gb 142??????

Much better fit for what you need. Comes with the Am-10 for ODR built in too. Mad Dog

Mad Dog!!!!!!!!

Glenn is correct.....................

If you require several different temps, No individual control will be able to achieve that WITHOUT specific piping strategies in place. Injection mixing would be the most accurate. Mad Dog

Joe@buderus_2

The R2107 control can provide two different water temperatures when the optional FM241 module is used for the application. The FM241 modle will control an injection valve or mix valve motor to provide a lower water temperature for the radiant. Depending on the budget, two motorized mix valves can be used (one controlled by the FM241 module and the other controlled by the optional TC-62 motor we offer), one motorized mix valve (controlled by the FM241) and one manual thermostatic valve, or two manual thermostatic valves can be used to control the different temperatures. It is suggested to consult with the contractor and discuss which control strategy fits the budget and which controls he is familiar with.