Water heating

[fourustircom]

Hi, Folks!

I've probably asked this before, but what is the best way to go with hot water heating, side arm or flatplate? My B-I-L says side arm is better and cuts the electric bill some. My dealer says flat plate will preheat the cold wated going in and the water heater will only have to maintain the temperature. Flat plate is less expensive and easier to install compared to a side arm.

Opinions?

Thanks!

 

[ericjeeper]

you need a pump or flow for plate

But for a sidearm. which if you can solder you can make yourself. Natural convection does the trick for preheating your hot water.

 

[ant]

i have a sidearm and it works out well for us.(so far)

 

[oneoldbanjo]

Believe it or not....I have both. I installed the side arm first - but I only have a 40 gallon water heater and got concerned about having enough hot water so I added the flat plate even before we started to use the system. My side arm system is a 2" copper pipe that the OWB water flows through with a 1' pipe inside that the water heater thermo-siphons through - I did get a pretty thick plate to help avoid pressure loss as my supply lines are over 130 feet long (I will count the number of plates tonight). I have a ball valve in the 1" pipe so I can shut the thermo-siphon off in the summer and prevent the water heater from doing strange things when the OWB is not in use.

The flat plate works very well and the water heater insulation is enough to keep the water plenty warm for use even if we are gone for 12 or more hours and even after a day it is still plenty hot. The flat plate works so well that we keep the valve in the side arm turned off to prevent the water from getting too hot. If I load the OWB up and we leave for a few days I only need open up the side arm for half an hour or so to get enough hot water to get back to normal. I have the electric elements in my water heater turned off when the OWB is operating and we have more hot water than we could ever begin to use.

At this point I don't know what to recommend for you - our flat plate works great - but I have never had a chance to operate the side arm one alone and it may very well work great all by itself. The flat plate will not work to keep the OWB from freezing if your fires goes out and the OWB needs to get heat from the house - and the side arm heater will start to thermo-siphon backwards and heat the OWB by using the heat stored in the water heater. That is the reason that I keep the side arm heater valve closed and the water heater elements turned off most of the time - if my OWB temperature drops below the low temperature setting of 140 degrees on the water heater (or whatever I set the water heater temperature to) I don't want to be using expensive electricity to keep the OWB water at 140 degrees.

 

[Geez]

I've got the next step up from a side arm. It's actually a copper coil inside a small rectangular tank. The OWB water is pumped through the tank (water jacket) before it goes to the heat exchanger in my plenum. Potable water is pumped though the coil in the same way as a regular sidearm heater. I have NEVER run out of hot water, and I have the breaker to the water heater shut off.

 

[WVwoodsman]

I am running just a flat plate and have the electricity (breaker) to the hot water tank turned off. I have never run out of water.

 

[tanker]

I run a sidearm due to the fact we've got very hard water and even with a water softener,I was afraid that the exchanger would plug up in time.When we are running the C.B.,no electricity is on to the water heater

 

[iCreek]

Plate Exchanger

I have an AIC Plate Water to Water Exchanger and it seems to work great. I would install which ever one you think would be easiest for you to install. I picked the plate cause it seemed easy to mount and run the PEX to.

 

[HUSKYMAN]

Not sure how a side arm saves electricity, if you have a system like mine the water goes from the boiler to the plate exchanger then to the exchanger for the home heat. I would still have to pump the water to the house exchanger regardless of whether I heat my hot water or not.

Anyways I vote for the plate exchanger, you will never run out of hot water. Take a bath, wash the dishes, do the laundry all at the same time.

 

[nathandrews]

The sidearm has worked really well for me. I never run out of hot water even when demand is really high, and it saves me about $25.00 a month on my electric bill. The power to it has been off since I hooked it up two years ago.