Air Handler/Heat Exchanger

I am running an EFM DF520. It is heating a very large house (roughly 5,500sq ft). Half of the house is hot water radiator and the other half is forced air. The boiler sits in the basement which also serves as our garge. I recently put a new 1/3hp air handler in with a heat exchanger. I've had decent results with it but was curious about one thing. I also have an add on water to air handler that i could put into my duct work making it have two air handlers. I was curious if anyone has every had any experience with a similar set up. Didn't know if it would create hotter air or not. Any information or feedback would be appreciated.

Thanks

For clarification, are you wanting to put them in series to a single common duct? Or divide/split the duct and have 2 separate air zones?

Both are possible, with the 2 air zones you could have 2 t'stats and better temp. control of their respective individual areas. With them in series, first one would do pre-heat for the second one, but would lack the individual areas temp. control possible from having them split into 2 air zones.

It would be much to difficult to reduct everything to make 2 different runs. I was thinking of having them in the same duct run. Was curious if it would create a better heat or not. Just curious if anyone has ever done that.

It makes sense that you could increase the air temperature more with the greater heat exchanger area of two air handlers...but it will also create more of a pressure drop in the ductwork...you may have to upgrade the blower motor to do the same job.

Do you have a hard time getting the air warm enough with your current setup? What are the supply & return temperatures going to the air handler's coil?

CoalBurner5 wrote:It would be much to difficult to reduct everything to make 2 different runs. I was thinking of having them in the same duct run. Was curious if it would create a better heat or not. Just curious if anyone has ever done that.

The second coil would probably increase the temperature 30% of what the first coil does assuming they were at the same temperature.

I honestly couldn't tell you the supply and return temps from the boiler to the air handler. I never really checked it. I do have the hi low limit on the boiler set at 190/170.

The house is just a little drafty and i was hoping to get a hotter temp from the furnance without having the boiler push hotter water.

Yes they would both be set at the same temp and probably run directly from the first heat exchanger to the second and then return back to the boiler on the same run.

Just looking for a more efficient way of heating without raising the costs. Any other suggestions or thoughts?

Should i try it or not?

I honestly couldn't tell you the supply and return temps from the boiler to the air handler. I never really checked it. I do have the hi low limit on the boiler set at 190/170.

The house is just a little drafty and i was hoping to get a hotter temp from the furnance without having the boiler push hotter water.

Yes they would both be set at the same temp and probably run directly from the first heat exchanger to the second and then return back to the boiler on the same run.

Just looking for a more efficient way of heating without raising the costs. Any other suggestions or thoughts?

Should i try it or not?

So the air handler isn't heating the living area to a comfortable level? Does the fan in the air handler run continuously or on/off? Does it blow cold air at first and then warm up?

Time to start sealing the drafts in the house.

yes i'm sealing the drafts, but with the garage under the living area we all know that the house won't be conpletely sealed.

Yes the air handler is on, and off on and off. about 15-20 intervals before it turns back on.

I do have an aquastat on the loop to the air handler where i can adjust the temp for the air handler to turn on and off for the water temp. I think i will play with that a little this weekend and probably turn my boiler hi low to 200/180.

I guess my question is: would it be worth putting the second air handler in vs loosing the forced air pressure?

CoalBurner5 wrote:I guess my question is: would it be worth putting the second air handler in vs loosing the forced air pressure?

First you better know the answer for what was asked by *Rob R*, "what are the water temps?"
Adding another air handlers does nothing if the additional btu's are not available.

Assuming extra btu's are available, does each air handler have it's own blower?

If not, you will be disappointed. This is not going to be the slam dunk solution you are looking for.

Now, if you have enough extra btu's and enough blower fans cfms to overcome the added pressure drop, then you may get there.

FInd out if your air-handler has a standard electric motor or the newer ECM type motor.