Gixxer, with all of that on one run, what kind of water return temps do you have? What boiler do you have. I am just curious as to how much heat you can pull out of a run. I am pulling around 50 deg. out of my loop with a 1" line. Don't know how much more I should try, would like to heat the garage.
I actually have never taken a temp reading on the return line. Now that I am curious, what would be the best way to take the temp? Infrared thermometer?
The heat exchanger in the garage is the last one in the line, it's the largest, and it still works awesome. I can take the garage (approx 26X28) from 30 degrees to 65 degrees in about 10-15 minutes. The insulated pex tubing comes into the basement from the boiler, feeds the forced air furnace exchanger, then the water heater plate exchanger, then the 70,000 btu hanging exchanger in the shop, then, finally, to the 130,000 btu +/- (I believe it is 135,000 btu, oversized, but has a variable speed fan) hanging exchanger in the garage. The return line to the boiler from the garage exchanger doesn't feel a whole lot colder than the feed line into the basement. If you are worried about losing too much heat you can always put the water heater plate exchanger last in line. Even with the cold water mixing valve turned all the way up the water at any of the taps is raging hot. I used the pricey insulated pipe that my boiler maker recommended and buried all of the pipe 6' in the ground to minimize heat loss.
The boiler I have is a Hawken Energy HE-2100. It holds 400 gallons and I believe is rated to heat up to 10,000 square feet so I wasn't all that worried about heat loss or heating capabilities related to the size of the boiler. I was more concerned with not being able to flow enough water with all of the piping, connections and the few 90 degree fittings that I had to use to do the install all on a small taco pump. I was also a little concerned about putting too much load on the taco pump on the back of the boiler with how far the water has to snake through the pipes so I bought a spare, just in case. I haven't had any issues with the system yet (knock on wood!). Oops, actually I did! When I fired the boiler up this year most of the brass fittings were dripping. I found them to all be loose! I think the expansion and contraction of the brass going from 160+ degrees to 50 degrees caused this. I re-tightened all of the fittings and it's all good. One advantage of the HE-2100 is I still have one more outlet to heat a pole barn, pool, and hot tub! I now have a neighbor about 800 yards from my house so I don't know about running it in the summer for the pool and tub, but we'll see. He's already thanked me twice for keeping the road graded so I don't think it will be a problem.
Swyman, one thing that I would recommend, especially if you are experiencing 50 deg heat loss (which sounds like a lot to me), is to get a garage unit with a variable speed fan. The variable speed fans typically only come on the larger units which is another recommendation. Having a larger exchanger and larger fan running on a lower speed appears to heat the garage better and also appears to "rob" less heat from the exchanger. Maybe I phrased that wrong. By having the fan run on a lower speed in a two stall garage I think you get less heat loss. It just seems to run more efficiently. When I had the 70,000 btu (single speed fan) heater in the garage it would run all the time and since it points toward the door it would melt the snow outside. With the larger unit it no longer does that and the garage feels much warmer.
