These units mount into your existing ductwork or the hot air plenum in your existing forced air furnace. 50-80,000 btu models have 3/4" sweat inlet & outlet. 100-200,000 btu models have 1" sweat inlet & outlet. Available in various sizes. click here to go to www.heatexchangersonline.com. Connecting your lines into your heat exchanger via a Kitec fitting is an example of where some soldering would be required. You may want to get advice from your distributor, boiler manufacturer, an HVAC specialist or plumber to decide which size of exchanger is appropriate relative to the size of space you are going to hear.