Floor Heat

[Flamingo]

I have a small 3 bay
wash/ I live in Tennessee /sometimes cold winters/sometimes mild/ Is there a way to have floor heat without using the big boilers / I have seen post talking about on demand..can someone give me an idea how I would connect this to my floor heat pipes? Thanks

 

[pitzerwm]

I had on demand heaters (2) for my 6 bay, and 25 years later they are still working fine. It was an open system, a 55 gal barrel with 50/50 anti-freeze, when the temp dropped to 34F a pump (mult-stage) pumped it thru the pipes, when the return line read 70F, the pump continued to pump but bypassed the heaters. No freeze ups.

 

[Flamingo]

Wow, I didn't realize the on demands have been around that long! The Open System is just a 55 Gallon Barrel with no top on it,where the air escapes as needed I assume?Thank You Very Much for the reply// Steve

 

[Buzzie8]

Bill,
Do you think your design would hold up in sub-zero conditions? I think I might try to use your design in one of my washes this year.
Buzzie

 

[pitzerwm]

Well, the layout of the tubing in the bays has a lot to do with it working right, they didn't do mine real well, so I sometimes had ice around the trough. We would be around 0 some, but usually I shut down some of the bays, although continued to run the heat. You could plumb it so you could just add another heater in parallel. I usually only ran one of the two.

 

[Buzzie8]

Bill,
If it would not be too much work for it would be greatly appreciated if you could draw up a quick hand drawn schematic. Here is how I am assuming you have it plumbed:
1. Pump draws antifreeze from open barrel.
2. Fluid is pumped into two wall mounted on demand heaters (BTU's ?).
3. Fluid then is dispersed to bay manifolds.
4. Fluid returns to top of 55 gallon barrel.
5. By pass of of on demand heater with solenoids when temperature is above ? with thermostat.

Question:
1. Where do you measure temperature? Concrete, Outside, or Fluid or all three?

 

[pitzerwm]

You have it right. There was a senor for outside temp and another one in the 55 gal barrel.

 

[Flamingo]

Thanks, For the extra Info/

 

[Buzzie8]

Bill,
Still curious about one thing, if you daisy chain the two demand heaters how do you regulate the heat. I want to use two 199,000 BTU Takagi's. The heated anti-freeze could be very hot while entering the second unit. I realize this is a way for the heaters to keep up but not sure how I would regulate each units output.
Thanks,
Buzzie

 

[mjwalsh]

equal but separate intake to the units suggestion

Bill,
Still curious about one thing, if you daisy chain the two demand heaters how do you regulate the heat. I want to use two 199,000 BTU Takagi's. The heated anti-freeze could be very hot while entering the second unit. I realize this is a way for the heaters to keep up but not sure how I would regulate each units output.
Thanks,
Buzzie

Buzzie,

It seems that if you balance the flow equally to both heaters & then have a common manifold back to the 55 gal drum afterwards it would address your concern. I know my condensing hydropulse boilers are more efficient with colder water coming into them.

One thing that I try to avoid is having our 50-50 mix antifreeze heated up directly by the fire in any boiler because of the efficiency loss created by the less heat transfer of the antifreeze vs normal water --- even though the same amount of BTU input is being used. Compact Spirex external heat exchangers solve that.

How significant your gas bill would factor in whether what I suggest makes sense. One caveat ---- depending on the specific heater --- thermal shock could be an issue.

Do they even make "on demand" condensing heaters?

MJ

 

[Buzzie8]

I was reading through this website today and I thought that I read they were running glycol through their Takagi units:

http://www.radiantcompany.com/heatsources/Takagischematics.shtml

Your suggestion on running two feeds to the manifold from each unit independently makes sense.

 

[pitzerwm]

You would not daisy chain them, but in parallel. The barrel temp to start would be room temp. when it reaches 70 you would bypass the heaters, so the temps wouldn't be an issue. Those heaters just take whatever temp is introduced it is kicked up 20-50F depending on the heater and your settings.

 

[mjwalsh]

Buzzie --- Interesting Link

I was reading through this website today and I thought that I read they were running glycol through their Takagi units:

http://www.radiantcompany.com/heatsources/Takagischematics.shtml

Your suggestion on running two feeds to the manifold from each unit independently makes sense.

Buz,

Your link applies more to floor heat where glycol is not so critical & the fluid tends to be needed to be much hotter. The system on the diagram (exhibit A) actually warms the air much more than if it was designed to just keep the ice off the floor as in Bill's deicer system. The diagram diagram has a nifty way to include the domestic water with the mixing valve without the use of another dedicated unit. I assume the units have their own way of detecting too little flow to prevent burn out of the unit.

Exhibit B is both sad & funny because it gives an example to hopefully offset some lunatic inspection department employee doing everything in his or her power to stop us from carefully tailoring & installing our own system. That includes following the original manufacturer's intent more closely also. The contractor from hell --- can have extra skills when it comes to ganging up on the operator & setting the stage so insurance companies, & less than ideal lawyers can play around in court more than they should be allowed to.

To be fair --- I guess the pendulum can go either way too far when it comes to authorities in power. I was visiting with one of the better much more rural electrical inspectors with his wife yesterday in our laundromat & he told me that the state board of electrical needed to deputize many contractors because of the severe flooding in parts of North Dakota --- especially in the Minot area. There sometimes is tension between rural & city slicker enforcement.

mike walsh king koin of bismarck