Home Piping getting ready for Solar

John Starcher_4

Don't you need a pump in the primary loop? What moves the water from the solar tank into the loop????

Starch

Wayco Wayne_2

I drew up a picture of my piping. I finally started on it today.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"Let me know what you think. WW

hot_rod

some thoughts

Build the load shedding (dump zone) right off of the solar pump station. Caleffi has a 3 way zv kit to do that. No need to go into the primary loop for "shedding."

Are you using the indirect as a buffer in series with the boiler? If so pipe all the loads and solar input as P/S. You would need to maintain a fairly high boiler temperature that way, for DHW. Maybe pipe the indirect as a priority series loop, although you lose the buffer feature.

Page 27 of I-dronics 3 show this with a HydroLink as distribution, although without the indirect in the primary loop.

How many and what type of panels? what size solar tank?
With over-heat protection enabled on the control, and the re-cooling feature enabled you may not need a load shed zone.

I've been running a 3 panel 78 sq ft array of flat panel collectors without any load in Milwaukee. The 119 gal. tank approches 200F every sunny day, but the re-cool feature pulls it down to 138 by the next morning.

Ideally you would use the stored energy, but we don't have a DHW or heating load, yet on the system.

hr

Wayco Wayne_2

Thanks for the input guys.

The drawing didnt come out too sharp so it may not be clear. This is a 2 pipe primary secondary system, not single pipe primary/secondary. The boiler has it's own circulator not shown in the drawing. (sorry). All the returns pass through the top HX of the solar pre tank except for the return line for the indirect water heater. The return line for the indirect tees in after the HX of the pre-tank. The top of the solar pre-tank is being used as a buffer tank and/or a heat source depending on the amount of sun available. The boiler is riding an outdoor re-set curve so it won't need to fire if there is enough solar hot water during the day. Also not shown is the drainback tank so I don't have to worry about over heating. I'm using 4 AET flat panels sized 4 x 10. The dual HX storage tank is a 120 gallons Vaughn solar tank. I don't have room for more storage so my strategy is to run the radiant floor up high during the day and fill the house with heat so we can coast on toward the night with that depending on the heat loss. The panels will be angled for the Winter sun.

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Wayco Wayne_2

Hor Rod!

I remember talkking to you up at the Rad fest about a variable spped controller. Do you guys have anything for drainback yet? Also you spoke of some piping arrangement for the drainback tank that lessened the noise from draining down. Could you refresh me on wht that was? Thanks.

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hot_rod

Drainback with Ergomax

Here is a system I installed yesterday in my shop. I wanted a pressurized drainback with a lot of HX surface. I had a scratch and dent Ergo kicking around, soo.....

I added an additional 1-1/4 nipple in the top for the coaxial drainback tube. Then a small DHW recirc pump moves the DHW from my Solar Phoenix through the copper inside the ErgoMax.

The sun is just coming up, so by days end I'll know how it performs. I also boosted up,the insulation inside the Ergomax jacketing. I'm pumping the drainback with a Grundfos Alpha pro at 47W.

Check with Dale at Radiant Engineering. He turned me onto the coaxial hydro vent. I think he plans on building them for sale. It's basically a tube in a tube to quiet the drainback, and also increase drainback velocity. It really evacuates the collectors quickly. My 4 panels drain back quickly, and quietly in about 25 seconds!

One concern with dual coil tanks. It is hard to pull much heat off the top coil when it is in a tank of still water. HTP told me about 10,000 btu/hr off their top coil indirect. Adding a recirc on the tank increases that to about 40K. But you give up the stratification. Pros and cons.

Resol does make a drainback control. it's not yet listed for US sale. Maybe try Victor at Solarnetix about a prototype or one he brings in through Canada. It has the option to start two pumps for 5 minutes and drop one off, or use variable speed and a high head circ.

By elevating my drainback tank I have only 10 feet to lift. The Alpha pro seems to be working just fine. I get 5 GPM through the 4 -28 square foot panels, and low power consumption.

You might get by with a regular solar control and a single pump, depending on your lift.

hr.

jp_2

snowmelt

i would think the snowmelt return water would over cool the solar tank? causing an unwanted cold sink?

Wayco Wayne_2

The snow melt

seldom gets used here in MD. We don't get much snow. I was thinking it might be a good dump zone though. HR I would love to see a concept drawing showing the piping of the ergomax. I priced a solar drainback tank today and my teeth fell out when I heard the price. I'm thinking of using a 20 gallon electric water heater instead. BTW, I just put in my first Phoenix last week. Ran great. WW

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hot_rod

any tank

can be used. I like the pressurized type of DB systems.

Here is a SuperStor that I welded, or had welded:) some additional ports for the sight glass and coaxial tube, in the top.

I believe SuperStor has, or will have a drainback tank available.

Sure a small electric water heater tank could be used. You'd need an external Hx of course. Actually you get good HX bang for the bucks with a small flat platen exchanger. Costs you an extra circ, but much better exchange. Unless you have a tank full of copper like the Ergomax or Thermomax.

Check out these drainback tanks from Florida they seem reasonably priced and may give you some ideas.

www.energylabsinc.com

hr