Hello everyone! I am new to the forum. Just finding it and reviewing some of the topics has been a great help. Now I have a question. We are looking at setting up our radiant floor heating system in a new construction. We are off-grid with a 1300w solar array so are concerned about pump and control box power requirements. A radiant floor company in Vermont has a new "Alpha" pump that is supposedly high efficiency but regardless, there will be a 4-5 watt constant draw from the control box that I'm not too happy about. If we are going to have radiant floor heat is this just something we'll have to deal with? Other than setting up a solar thermal flow system what is out there in terms of the highest efficiency systems for moving liquid through the floor?

you can run the alpha in low fixed speed which is an 8 watt max draw. however it's very weak and requires serious attention to the loads and hydraulics of the design to do that.

there is no need for any additional draws if you substitute a manual control (turn it on, turn it off) with line voltage thermostats, or with analog non-electric zoning controls.

to really nail a good off grid system requires some serious design chops to also ensure comfort and performance. but done right you can get away with less than a 10 watt draw in total for most situations.

We have a couple pumps that may be of use for your application, these are ECM motors, on of control no stand by loss.
The B&G Ecocirc Solar Circulators are a 12-24 volt unit, reasonable head you could do several 250' loops on a pump.
Also look at the B&G ecocirc 19-14 auto, this is more of a work horse but will turn down to 5 watts .Also ECM motor
Dan

Thank you both very much. I'll check into the Ecocirc pumps. The "line voltage thermostats" and "non-electirc zoning controls" are new terms to me so I will look into those as well.

Hello, I went to your website, nrtradiant.com to see what you might be able to provide for my project, and noted your consultation directions. I want to say first that our house has been a multi-year project, underway for the past 5 years or so. While we have detailed plans covering the house building, we laid the Pex tubing in the concrete slab very early in the process, just trying to plan ahead that we might want to incorporate radiant floor heating. As such, there is no indication of a heating system in the plans. It is laid out as a single zone (~400 sq. ft) walk-out basement slab with two 300' Pex runs. What I am most interested in at this time is in designing an efficient control panel, pump system for the floor based on our need to be as efficient as possible given we are an off-grid project. I would be happy to provide a floor plan and photos of the Pex layout, if that would help but there is really nothing we can modify in that regard at this point. I will await your advice. Thank you. Jeff

if you send us what you have we'll let you know what we can do. Not being able to affect the concrete pipe layout is a detriment to the final quality of the system in many cases, but it's not an insurmountable obstacle. it just may require some different decisions if there are any comfort tradeoffs that will occur if the layout is not adequate for the loads or floorplan.