Highest output heat exchanger

BeardedWoodsman

I have an outdoor wood boiler running at 180 degrees F, what heat exchanger would i use to run this to a closed loop system at 15 psi to get as close to 180 degrees F out?

hot_rod

That is what is know as close approach sizing, where the output is within a few degrees of the inlet temperature. So it generally takes more surface area to get those close temperatures, larger dimension HX or more plates.

The best way to size is using one of the free online calculator programs. You need a few pieces of data, temperature and flow rates. You know two temperatures, you need to know or guesstimate the flow rates.

The programs usually give you a few option for sizing. Manufacturers will also help you with sizing if you contact them at their websites, or if you have a local rep.

This example is for domestic water incoming at 50 f

GroundUp

That is entirely dependent on the BTU load and piping. Your wood boiler may be set to 180, but it has a differential (typically 10+ degrees) as well as some line loss underground, plus the probability that the water leaving the jacket is not actually what the sensor is reading. Many OWB (Central seems to be the worst) will show 180 on the display but are actually only sending 165-170 out of the supply port due to poor internal mixing and sensor probe location. Simply put, if you always need 180 degree water supplied to your emitters, you will never achieve that with a wood boiler set to 180 on the high side.

What is the connected load on the indoor side?

hot_rod

Does the building heat adequately now, with whatever temperature that actually enters the building?

Often times on a single pump system with undersized runs, you may not be getting adequate flow.

If the furnace comes up to temperature and shuts down, but the building is not heating adequately, that is often an indication of undersized lines from the furnace.

plan on loosing a few degrees if you install the HX inside.

IF the building struggles or falls behind on cold days, you have two means to increase heat output. Increase supply, or increase flow rate.