Hydronic Radiant Heat

lsag02

I am bulding an addition to my house and considereng hydronic radiant heat the only source for heating the additon and some existing space like bath. I did a lot of research on various options and still do not have any solid idea what heat source to choose and what the complete hydronic radiant heat floors system consists of. I also have troubles finding any knowledgaeble contractors who can advice me on various options, costs, etc. I would be very thankful if someone could shed clarity on this issue.

The addition is ~1500sf, I live in central NJ, the fuel is NG. Current heating is forced air furnace, I do not want to touch it, new system will be an addition, not replacement. The addition will include big room on slab foundation and second story area. The house will be well insulated: all attics R-49, walls R 19.5, floors under second story addition will be probably R-30 and the slab will have at least 2" (R-13) foam insulation. All windows are E4 Andersen windows.



I want at least two zone hydronic system for new addition: one is for big room on the slab and another for second story area. I intend embedding PEX tubes into the slab tied to rebar, and for second story with hardwood floors I will put plywood panels with grooves and aluminum backing and run the PEX tube inside the grooves.



I have very limited space in my basement where new system can be  installed. So the ideal approach for me for the heat source would be radiant heat source and water heater combination unit that does not take much floor space and no hogher then 6' 8". This unit will also replace existing NG water  heater and provide hot water for entire house.

Unknown

Ultimate Radiant Floor Heat Source

Too easy.

ModCon high efficiency, wall hung, natural gas, condensing boiler with companion water heater sized to the load.

Ask the local contractors about ModCons and radiant floors; if you get anything but unbridled enthusiasm, hang up and call the next number on your list.

Another very useful interviewing question is heat load analysis. All proper radiant floor heating systems start with a room-by-room, computer generated, heat load analysis.

Again, if your contractor suggests this vital step is unnecessary, you have shortened your list of "professionals".

Mark Eatherton

Think......

WarmBoard for the upper floors.



www.warmboard.com



THis will keep both radiant floors on the same plane as it pertains to operating temperatures, and will simplify the installation.



ALso look into non electric thermostatic radiator control valves. Danfoss, Oventrop, Honeywell.



ME

Unknown

Just curious...

How will Isag use TRVs on a radiant floor application?

Mark Eatherton

Easily...

Danfoss and Oventrop make a remote tube capillary control. In the room sets a "thermostat" about 4" X 4" square. On the other end of the cap tube (up to 33' away) is the control valve. It requires a little fore thought and planning, but it is done on a regular basis and the comfort is extremely good. This is a proven technology from across the pond.



The valve and thermostat provide proportional control, meaning if the rooms needs just a little heat, the valve opens just a little bit, and if it needs a LOT of heat, the valve opens all the way, and as the room approaches its set point, it idles back and stays just below its target. Should the room start receiving internal gains (bodies, lights, solar etc) it senses that and shut flow completely down.



We Americans are so fixated on 24 volt controls, that we fail to recognize simple and efficient controls that have been readily available for many years. It requires a complete change in thinking, and should incorporate the use of modulating pumps and modulating boilers in order to deliver maximum efficiency and maximum comfort.



Here are some pictures.



ME

lsag02

Condensing Boiler / DWH for radiant heat and hot water



I did some research and found Triangle Tube Prestige Excellence Combination Condensing Boiler Natural Gas PE110-NG . It has built in 14 ga indirect water heater. I wonder if it will provide enough hot water to supply Jacuzzi, custom shower with multiple shower heads and for instance a washer?

It is also good that it can be vented with PVC through the rim joists to the side of my house. I don't need to run the vent pipe through two stories and the roof.

Any other Condensing Boiler / DWH combo models to consider?

Also what other components do I need to install for hydronic radiant heated floors? I am planning at least two zone system.

Unknown

European panel radiator

Thank you Mark;



I am familiar with TRVs and have been using them since the late 80's. I also use Oventrop, Danfoss along with a few Hart, Honeywell and Herz. Nothing better for European panel radiators and no electricity to burn as you so astutely point out.

Panel radiators may be a viable option for the second floor in this case but Isag discribes a sandwich for the second floor. 

How you might use a TRV to control a radiant floor, wall or ceiling panel?

Mark Eatherton

Morgan...

As I stated, it requires a little change in design and thinking. The piping and distribution system would be a long running manifold design, and each RFH zone would have a single control valve, and to that valve is connected the TRV. THe TRV really doesn't care what the heat source is, it is simply looking for a temperature condition that will be delivered by the heat emitter.



The control valve is connected to the supply or return (flow direction is critical to avoid THUMPING) I typically run a flexible 3/4" PVC chase from the valve to the thermostat location just in case there is a need for replacement in the future. This requires that the thermostat be within 33' of the control valve (forethought) and if need be, I have run a single supply loop serving the manifold or (in some cases) single tube circuit near the thermostat location.



If the zone has a need for more than one radiant tube circuit, then the control valve is connected to the manifolds supply or return line.



I have used them on high mass radiant floors, low mass radiant floors, low mass radiant ceilings and medium mass radiant walls, and they have worked flawlessly on all systems. Extreme comfort and temperature control. I have been employing them for around 10 years in large surface radiator applications and have had ZERO failures.



HTH



ME

Simply Rad

Oventrops

`Thanks to ME I can add another 5 years of flawless operation using the non electrics.

I have to admit I was leery of them but I listen to ME(Yoda) and used the force.  They are simple yet extremely comfortable.  Most customers are alittle reluctant at first sight.  But after alittle education they open up to them.  By then end they love them because they are so simple  The flex PVC is the only way to go, provide sold conduit and protects form kinking.  If there were a problem the PVC enable you to replace them easily.  Try them for yourself and you may not go back.  You can even lock them and limit the temperature range.  The pics I attached shows one of 36 non-electrics we used in the home. 

Oh and they are the perfect system with differential pressure pumps.  Ahhh what a great system



Jeffrey

Simply Rad

Oventrops

`Thanks to ME I can add another 5 years of flawless operation using the non electrics.

I have to admit I was leery of them but I listen to ME(Yoda) and used the force.  They are simple yet extremely comfortable.  Most customers are alittle reluctant at first sight.  But after alittle education they open up to them.  By then end they love them because they are so simple  The flex PVC is the only way to go, provide sold conduit and protects form kinking.  If there were a problem the PVC enable you to replace them easily.  Try them for yourself and you may not go back.  You can even lock them and limit the temperature range.  The pics I attached shows one of 36 non-electrics we used in the home. 

Oh and they are the perfect system with differential pressure pumps.  Ahhh what a great system



Jeffrey

Unknown

TRV heaven

I have a similar experience with TRV and thermal actuators which I started using years ago when designing systems "off the grid".

My question to you was more about application e.g. fixing the bulb in a slab, wall or sub-floor and the controls that work with them. Without and end switch to turn on the boiler, I suppose you drive the whole house on ODR?

Simply Rad

Constant circ

Whether its a mod con, heat pump or solar combisystem we use constant circ with outdoor reset.  That what I was trying to say with using the differential pressure pumps.  They are design for constant circ.  Yes the heat system is delivering heat all the time and my zones modulate as needed.  Sweet system and extremely simple.  Sometimes we use in addition to the ODR we use indoor feeback.  Must be careful but if it works its my favorite.  We have been using the Vitodens for years and it has a unique feature.  You can remore mount the master control and use it as the master zone thermostat.  It controls the boiler, that zone constantly circulates, and the rest of the zones fall under the umbrella.  Must be careful though,any external or internal heat gains can create problems with this system.  Lots of different ways to offer comfort.  Oh yea the PVC conduit offers a great way to replace a capillary if there would ever be a problem. 

Jeffrey

Unknown

Vitodens

 I will try it on my next Vitodens!



Thank you kindly.



MA

Mark Eatherton

An article to help you.

The days of Bang Bang operation are leaving us fast. With the introduction of ECM technology, our worlds can now fully modulate.



Cap tube replacement is facilitated with the flexible PVC conduit.



Enjoy!



ME



http://contractormag.com/columns/eatherton/hydronicahh-everything-modulation-1209/