Off peak Boiler w/ Gas Furnace

EricAune

I am considering installing a water to air exchanger on a gas furnace, using the boiler as a primary source. What type of relay/control would work best?

I would need to operate the fan independent of the burner,
Using a Thermolec boiler, would the dual fuel control help?

Thanks,
Eric

don_205

You should

You should check the pressure drop on that coil that you plan on installing and make sure your blower can support the extra load.

May I ask why you want the flame to heat the water and then the water to heat the heat excanger and the heatexchanger to heat the air verse...the flame to the hx to the air?

I'll take it that it has something to do with being a plumber and the love for the wetstuff.

EricAune

Nice Try

Just need to control the blower/fan independently. Don't need the flame if it has electric (off- peak times) at the boiler.

You know for a guy that just bangs tin around, one could assume you think pretty highly of yourself

don_205

I just

I just asked a question? You can see more into if you like.And yes,I do think highly of myself.

You have several ways that you could control the fan.

1-you could add a surface aquastat on the return side of the coil and wire it into the heat speed of the blower.

2-or you could add a flow switch that can be wire into the blower.

If you try wiring it up on the low voltage side you may get some bleed by voltage that would make other things come on like the ac unit or something like that.So it would be best wiring it in on the high voltage side.

Maybe one day Dan will have a way people can put a smilely face up after their post for guys like you that assume people are trying to be a butthead.

Oh well. I'll not ask about the pressure drop again of the coil being a issue when it comes to airflow being I do not want to upset anyone.

Peace!

EricAune

sorry man

Hey thanks, I was just kidding too. I have figured the size of the coil, matched it to the fan, output/efficiency etc. Just get frustrated when its the controls that laydown speed bumps in the road of completing a job is all.
Thanks for the advice, I really appreciate it.

Maybe next time you think about changing out some plumbing you could give me a call....I know how you hvac guys lust after the wet stuff...jk..lol

thanks, Eric

Bryan_16

thermostat

Why not install a thermostat that energizes the blower on a call for heat? Simple and cheap.

don_205

other issue

You would still have other issue.Depending on how far the boiler and circ is away from the coil there might be some issue with cold air blowing awhile before the heat arrives.

Also the other issue is depending on what boards he has in the furnace.If the fan is also being energize in heat mode he may get high speed which may be a issue with low temp air
and he may even drop his water temps to low going back to the boiler.

I know not a issue with a mod/con just thought I would throw
it out there.

don_205

You dare say

We hvac guy lust after anything that has to do with hvac.

Just think for fourteen years now I've been coming to the wall learning from the best.yet everytime a guy that come to the wall that is know are assume to be known as just a tin bender he is frown upon.

Something never change.Oh well,i'll keep learning from you all and you guys keep your ear closed to anything that has to do with VAC.Just keep this in mind the next time you lose a job to the forceair guy......ask yourself was it because he sales a cheaper system or was it because he was able to offer more.

EricAune

Right on

I agree, that's why I'm here right? I don't like to think in that reverse direction...we both have great jobs, places like this bring us together and allow us to figure things out. I am always open to any technicians eperience/advice. Once again, I didn't mean it like that
Thanks,
Eric

don_205

Hi eric

I'm cool with it.I know if you and I were on a job site together we would be having even more fun then what we can do here.Heck, on the right day you might even hear me call you turd chaser only because you could see my face and know I was just kidding.

I would like to hear more about off peak demand.Does that mean you guys get the gas/electric cheaper then at any other time during the day?

TIA.

EricAune

off peak electric

We are pretty lucky in this part of the country. I'm in Minnesota. I know you hear the words "Electric boiler" and say WHAT? Our electric utility is still real cheap; about 8-10cents/Kw. We have been using electric mini boilers for years, a few are high quality and perform very well.

The electric providers have alternative programs to promote using electric for heating, and domestic water. The most common would be the "Duel-Fuel" program. This would require utilizing electric as the main heat source having a fossil fuel (not wood) as a back-up.

The provider requires a radio control meter socket (separate from main meter) that they use to interrupt service during peak demand periods. (usually at 4-10pm and 6-9am) In return the end user gets a 30-50% discount per Kwh. Not bad at all!