Interesting discusion with OWB installer.

[Bricks]

Was having some issues with our LP furnace. I had it narrowed down to the thermostat but wasn`t sure so I called the HVAC repair man. Turns out he does some installs for a local OWB dealer. Since I have been struggling on how to hook up my EKO 40 what a perfect opportunity to ask questions.

So I did.

So I asked him how to hook up my 4 zones. His suggestion was direct to the side arm continuous flow, then to the water to air exchanger in the furnace direct flow, pump and valve for a bang bang temp control for the infloor heat using a air thermostat for space temp control, and pump for my garage.


Not saying this would not work but I question some aspects and it does not seem the best use of the system resources.

Hard to get much simpler.

 

[heaterman]

Hard to get simpler......true.

But from what I can see of your description it would create a piping system with what could possibly be very high head. You also have no control of the water temp coming out of your hot water heater or any kind of temperature limit on the temp going to your floor. Both of those need some kind of mixing and control device to be safe and provide temps required by each type of system. One water temp does not fit all applications.

 

[Bricks]

It kinda bothers me this guy is actually doing installs this way.

 

[sdrobertson]

I'm probably walking the line here but from what I've seen about our local dealers of OWB, they are in the business to sell them but really haven't done very much research on how to efficiently transfer all the btu's. The manufacturers want the dealers to move appliances but don't put them through allot of training. It's easy to sell them and use a generic set-up that may work for most setups but not be very efficent. People get these things to save money so its easier to make the sale with the least amount of expense to set them up.

 

[flyingcow]

Got to agree with that last statement. Buddy of mine had a 6048 installed last fall. Happy it only cost $300 to hook into house(which it looks like a $300 job). It works, but...............?
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I told him what i had into my hookup. He was mystified I spent that much. (Actually haven't got the final bill). I'm happy. What he burns in a week will do me for at least a month.
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But whatever floats your boat.

 

[700renegade]

Bricks,

I'm no expert like many others on here, but from your brief description, the layout he suggested may be just fine. Without lengths and diameters I couldn't assume friction head is an issue.

You definately want the sidearm first. See how your domestic water temps are behaving before you install the mixing valve on the hot water line. I bought one but never installed it as my temps are liveable as-is ( but my corn boiler never ever gets even one degree above it's 170* set point )

When you say "pump and valve" for the infloor I assume it is pulling off the main loop w/ close coupled tees and is using a thermostatic mixing valve to blend that loop back to 105* or so. You don't say what the garage is using to deliver heat, but assuming it is a ceiling hung unit heater, you may be fine there too. Your only problem may be that the return water temps may be a bit low for the Eko ( not sure what they like coming back ).

If location of the piping allows it, you may want to pull the in floor off after the garage, as it has the lowest requirement for water temp.

 

[Tony H]

Judging by my setup it does not sound like a very workable design. I have a sidearm to DHW with a mix valve on the output then to an HX mounted in my gas forced air furnace and it works great but the water exiting the exchanger does not have much heat left to give up. A proven system with each "zone " drawing off a loop and adjusted to it's requirements seems like a better choice.

 

[700renegade]

Tony, how far is your boiler from your loads? My boiler is 185' away and I run a system nearly identical to what was suggested in the first post with no problems. I'll admit my return water temps are a bit low, but I pull off for the hydronic loop last since it only requires 110* water and it works fine. If your boiler has a small water jacket capacity it could cause problems I don't have.

 

[sandman59]

I do not understand going through the side arm heater first without any flow and temperature control. I run my lines from the EKO 40 directly to my oil boiler with branches going to the side arm heater. I control the amount of flow to the side arm heater manually using ball valves. I am setting up a automatic temperature control for the side arm heater, hoping to have it ready to go this season.

 

[700renegade]

The sidearm thermo-siphons the domestic water and will heat it to within 5* or 10* of the water from the boiler. If your boiler is at 180* your water in the water heater will hit about 170* or so. You put a thermostatic mixing valve on the hot water outlet of the water heater itself to achieve say 135* domestic hot water, you do NOT temper the water from the boiler. Google Watts 70A and you'll see what you need. About a $35 part.

A sidearm is the world's simplest heat transfer device - why mess with any ball valves or 'automatic temperature control device'? You want the 50 gal. in the tank as hot as possible to store BTU's.

 

[sandman59]

I guess it depends on your system. My boiler is already 100 feet from my house, running through the side arm would additional pipe plus the additional head pressure added by the side arm. I prefer to just use my hot water tank like it is not as a storage unit.