Homeowner replacing gas with electric, seek input

DanielFranklinHO

Here is a link to a blog for my hydronics project which is replacing my old DWH radiant system with a HydroShark3-10. Any advice, comments or input are welcome.



<a href="http://hydronicgarage.blogspot.ca/">http://hydronicgarage.blogspot.ca/</a>



Daniel

SWEI

Electric resistance boilers

do make sense in some areas -- I'll skip that discussion with the assumption you understand your fuel options and associated operation costs.



The Hydro Shark is based on a Stiebel-Eltron tankless electric water heater.  I'm not sure if they've modified the units or not, but you should inquire whether they have outdoor reset control on them.



http://www.thermolec.com/en/productview.aspx?type=product&id=62 has ODR and costs less than other options I am aware of here in NA.

Zman

Complex

I agree with swei on the outdoor reset. You system will be more efficient and comfortable with it.

You really don't need primary/secondary on a system like yours. Hydroshark is just specking it as a cya. If they will tell you the head loss and minimum gpm through the boiler you can easily do this with one circ.

The 10 kW model sounds a bit large. What was the output of your previous heater? Have you done a heat loss?

I would suggest a single mag/dirt separator rather than the Y strainers.

Why all the gauges? Do the math and forget it.

Carl

Rich_49

Less is more

Swei & Zman have both touched on some really good points . You should listen , there's a reason you sought advice here . Incase you decide to go witout P&S piping get rid of the air eliminator , Y stariners , and the P&S stuff and just use a caleffi 5461 Discal (magnetic dirt and air eliminator . If you must use the P&S for whatever reason still do away with the unnecessary clutter and use the newer Sep4 from Caleffi also ( #5495) , this is all of the above and a hydraulic separator to boot . Also , use a 10* ^T for a slab floor application , you'll experience a more even feel from the panel .

DanielFranklinHO

Thank you

 The rough heat loss calc I did came out at 12,000 btu/hr but I can't bring myself to trust that number or the assumptions I fed into the online calculator. It will be interesting to monitor the energy consumption over the next year with a dedicated kWH meter which I expect will yield an accurate figure.



Thank you for your insight and thoughtful responses.

Zman

Size

You had a heat source that met the load. What size was it? The heat loss you did sounds pretty close. Unless you are trying to program big setbacks,(not recommended with high mass radiant).you don't need to overpower this thing. This is why outdoor reset is such a good idea. Think of it as a big freight train, if you get it going to fast (hot) it is really hard to slow (cool) it down. People like to put lots of gauges on these things. As much as it is useful to know you supply and return temp to make sure you have proper circulation, in a properly designed system, watching the gauges is a little like watching paint dry.

SWEI

Thermolec B-6TMB

Has almost twice the output you need and should cost less than $1,000 including shipping.  It has essentially zero head resistance at the flow rates your garage will require.  It pairs perfectly with the little B&G ecocirc e3-4 Vario, which will draw under 10 Watts when running.



You don't really need an indoor thermostat, but if you install one, it should be used as a high limit controller (set 3-4ºF above the desired space temp once the ODR is dialed in.)  Leave the stat at its maximum setting during the process.

NYplumber

electromn

Look into electromn.com.

SWEI

Electro

Nice boilers, but no ODR under 10kW (unless something changed recently.)