When It's Too Cold...

Kungur · Post by **Kungur** » Sat. Jan. 04, 2014 8:19 am

So after few years of having our KA-2 supply radiant heat I have come to a conclusion. When the temps get down into the single digits it cannot kept the house above 62F. I think it may be that we have a large area that is carpet and it is just too much of an insulator. And maybe the "engineering" of the layout could have been better. Whatever we need to fire up the woodstove or the furnace to bring us up those extra degrees.
Here is an idea I have had kicking around in my head for a few days. Maybe the cold weather stimulates the brain cells! What if I "split" my system. By this I mean being able to shut down the radiant and run the untempered water to a water to air heat exchanger in the furnace? This set up would be used when it gets really cold.
Now another thought, see I told you the cold weather helps the brain!. Could I possibly run the water to air heat exchanger AND the radiant at the same time?
Looking forward to your collective advice!
Thanks.

blrman07 · Post by **blrman07** » Sat. Jan. 04, 2014 8:32 am

I would assume that when the radiant was installed someone ran a heat load needs survey? What did it come out to say you needed?

Rev. Larry

lsayre · Post by **lsayre** » Sat. Jan. 04, 2014 8:38 am

I have seen mention on this forum a few times of adding a few hot water baseboard kickers for those times when it gets real coal and radiant heat is too slow to respond. No idea of whether or not this will be relevant here, but I'm just tossing it out.

Fritzi · Post by **Fritzi** » Sat. Jan. 04, 2014 9:47 am

Sure.... The cold acts like a superconductor, increasing the efficiency of the electrical relays in your brain.

Totally plausible.

NWBuilder · Post by **NWBuilder** » Sat. Jan. 04, 2014 9:53 am

lsayre wrote:I have seen mention on this forum a few times of adding a few hot water baseboard kickers for those times when it gets real coal and radiant heat is too slow to respond. No idea of whether or not this will be relevant here, but I'm just tossing it out.

I agree,I would just add some hwbb on a separate zone to help boost temps in that area if it is accessible for such an application.

Hambden Bob · Post by **Hambden Bob** » Sat. Jan. 04, 2014 10:41 am

Kungur,I'll recommend this thread. His Home is 1800Sq.Ft and he's struggling also. It may help,and it may also define an undersized unit for the weather. Good Luck,and make it through !

Keystoker K2 Coal Boiler Temperature

Carbon12 · Post by **Carbon12** » Sat. Jan. 04, 2014 11:03 am

What temp are you running the boiler and what is the max temp you can safely put through the radiant tubing? You certainly can run the radiant and a coil or baseboard together but your boiler temps would have to be around 160/180 and you'd have to temper the radiant loop. Can and has been done successfully. Probably easier to just fire up the backup heat or some electric space heaters for the few times you may need it, however.

lsayre · Post by **lsayre** » Sat. Jan. 04, 2014 11:11 am

I have two simple adjustments that I can potentially make to the AHS S130 Coal Gun if the -15 to -20 degree temps cause my boiler to labor in trying to keep the house warm.

1) I have a single 3 speed circulator (with zone valves) and it is presently set on medium speed. How might either slowing it down or speeding it up affect the heat delivery? I've never played with it. Set it at medium at install time...

2) I'm at 175 degrees on the boiler (with firing at 165 degrees). I can bump it up to 180 degrees, or even 185 degrees.

Which of these options would be the preferred thing to monkey with to gain heat output if I find it necessary to do so? Or can both options effectively be utilized?

Carbon12 · Post by **Carbon12** » Sat. Jan. 04, 2014 11:20 am

I guess it might depend on whether the problem is the boiler cannot produce enough heat or, if it can, the heat cannot be moved fast enough to the radiation. Hotter water carries more BTU's and will, theoretically radiate those BTU's faster at same flow rate. Trial and error may be the only way to find out.

Freddy · Post by **Freddy** » Sat. Jan. 04, 2014 11:39 am

I have part radiant heat & part baseboard. In this cold, cold weather the infloor runs non stop & never catches up. I really don't notice though as the baseboard just runs extra to make up the difference. I can easily keep it any temp I want.

If all I had was radiant & I needed more heat I'd add baseboard or a kick toe heater (or two).

To get more heat without adding hardware, I'd first bump up water temps....but don't go over what plastic tubing is rated! As for pumping faster I'd try to measure the return temp of the water. If the return temp is more than 20 degrees different than when it goes in, then more pump might help, But, if you're pumping 180 in and getting 165 back, then you are dispersing all the potential that the hardware can deliver.

Short Bus · Post by **Short Bus** » Sat. Jan. 04, 2014 1:32 pm

Is your KA-2 running full time?

If not, then more methods of getting the heat out of the water are needed. I like baseboard in the coldest rooms.

If it is, then check on turning up the feeder, I'm unfamiliar with how the KA-2 work but many stokers have some feed adjustment. Be sure and clean your heat exchanger.

Boiler temperatures would be nice to know.

Post by **Lightning** » Sat. Jan. 04, 2014 1:45 pm

This might seem a little reckless but why not run the water temp closer to 230 degrees. You guys keep pressure in the system. Water won't boil till it gets to 258 degrees at 20 pounds of pressure.

Carbon12 · Post by **Carbon12** » Sat. Jan. 04, 2014 1:50 pm

I'm saving 200 plus degree water as the last card up my sleeve before I fire up the oil furnace. So far, 180 degrees is carrying the load quite easily.

Kungur · Post by **Kungur** » Wed. Jan. 29, 2014 8:54 am

Well this cold weather has really caused me to re-consider the original idea of a "split system". Having the ability of switching from the radiant floor heating to a water to air heat exchanger in the gas forced air furnace. The prices don't seem to unreasonable for the exchanger, but would like some info.
I would like to hear from those of you that have a water to air heat exchanger, info on how you installed it in the plenum, etc.. And pics would be great!
Thanks!

windyhill4.2 · Post by **windyhill4.2** » Wed. Jan. 29, 2014 9:15 am

If boiler temps are in the 180-200* range,mixing valve for the radiant system,water to air exchanger in the plenum can run the 180-200* water & easily cycle on/off with second tstat ,hooked to the gas furnace,just unhook the burner trigger wire so the tsat runs the fan only,not much different than those who heat with water to air system only. You will just have the best of both worlds,quick hot air heat with the benefit of warm floor heat.I believe coalkirk has a real good pic of his water to air exchanger setup,probably go the pics of boiler thread & feast your eyes on a number of setups there,enjoy the education.