DW / DHW / Nyletherm plumbing

[mustash29]

I put this in the Boiler Room, if it belongs in the Green Room feel free to move it.

My current domestic water supply is as follows:
- Submersible well pump
- Amtrol bladder tank approx 20 gal size
- Whole house 20 micron filter
- All this feeds into a 3/4" supply header
- 1/2" T to the side yard faucet
- 1/2" T to the garage faucet
- 1/2" cold supply to house
- 1/2" supply to oil burner tankless coil & anti scald valve
- 1/2" hot supply to house.

Only 2 of us here, 2 bath home, supply to dishwasher is mixed hot, we do mostly cold for laundry. The kitchen, baths & laundry area are located near each other in the rear center of the house. This is all plumbed with 1/2" which I have no plan to change. I am going to add a 1/2" outdoor faucet in the rear center of the house.

I am disconnecting the oil tankless coil, installing an 80 gal indirect & Nyletherm HPWH. The tank has 1" connections.

Is 1/2" cold supply into the tank & mix valve & 1/2" mixed supply to the house adequate? Should I upsize all that stuff to 3/4"? We typically don't have any issues with pressure surges, etc as we are generally only using one water source at any given time. The pump is set to cycle 60-70 psi.

 

[mustash29]

The 1/2" Watts mix valve on the oil tankless coil failed open about a year ago. I removed & capped the mix pipe for a quick fix. I have a replacement 1/2" Watts mix valve. Just wondering if I should use it or upgrade to 3/4" pipe and valve.

 

[tom in maine]

1/2" is fine. I use 3/8" PEX with no issues.

 

[jaoneill]

I put this in the Boiler Room, if it belongs in the Green Room feel free to move it.

My current domestic water supply is as follows:
- Submersible well pump
- Amtrol bladder tank approx 20 gal size
- Whole house 20 micron filter
- All this feeds into a 3/4" supply header
- 1/2" T to the side yard faucet
- 1/2" T to the garage faucet
- 1/2" cold supply to house
- 1/2" supply to oil burner tankless coil & anti scald valve
- 1/2" hot supply to house.

Only 2 of us here, 2 bath home, supply to dishwasher is mixed hot, we do mostly cold for laundry. The kitchen, baths & laundry area are located near each other in the rear center of the house. This is all plumbed with 1/2" which I have no plan to change. I am going to add a 1/2" outdoor faucet in the rear center of the house.

I am disconnecting the oil tankless coil, installing an 80 gal indirect & Nyletherm HPWH. The tank has 1" connections.

Is 1/2" cold supply into the tank & mix valve & 1/2" mixed supply to the house adequate? Should I upsize all that stuff to 3/4"? We typically don't have any issues with pressure surges, etc as we are generally only using one water source at any given time. The pump is set to cycle 60-70 psi.

FWIW, with only 2 of you the 80 gallon indirect is major overkill, a 30-40 gal will supply you with more (continuous) hot water than you can push through a 1/2" pipe. Take the savings and invest in an 80-100 gallon captive air (bladder) pressure tank for your supply. It will drastically cut the cycles on your water pump and save a bunch on the electric bill. With the 20 gallon your pump is "short cycling", i.e. running often for short periods. Due to the capacitors necessary to start the pump it uses more juice to start than to run for 10 minutes. A larger tank will have it running less often for longer periods but fewer starts = less electrical usage and much longer pump life.

 

[BoilerMan]

You could buy an electric water heater and save yourself some (a lot) of cash. 40gal should be good. The Nyletherm takes a LONG time to make hot water. I find it's about 10gal/hour+/- with an intake of 70F air. A larger tank would be needed if you use more than 40 gal at a time and at approx. 10gal/hr recovery.

If your tankless coil is still in good shape, you can pipe that to the electric and use it as a "poor-mans indirect" instead of the boiler coil being in the tank it's external and in the boiler (tankless coil). A bronze or Stainless circulator would be needed due to handling domestic water directly.

1/2 copper is all I use after the split from the bladder tank to the DHW, you are fine piping it all in 1/2.

TS

 

[BoilerMan]

invest in an 80-100 gallon captive air (bladder) pressure tank for your supply. It will drastically cut the cycles on your water pump and save a bunch on the electric bill. With the 20 gallon your pump is "short cycling", i.e. running often for short periods. Due to the capacitors necessary to start the pump it uses more juice to start than to run for 10 minutes. A larger tank will have it running less often for longer periods but fewer starts = less electrical usage and much longer pump life.

This is 100% accurate! I've been saying this for as long as I've been a homeowner and a contractor. I have a single 86gal pressure tank set to 40 cut-in and 60 cut-out. In the shower you'd never know we are on well water, nice long run time on the pump with no noticeable pressure swings. BTW my 86gal tank @ 40/60 holds 22gal or water between the 40 and 60. Set the air pressure 2psi below the cut it (38psi in this case). Do this while the pump is off and all the water is drained out if the tank, recheck once a year.

TS

 

[jaoneill]

Here is another angle: I set up an old 80 gallon electric water heater upstream from my indirect with a stat controlled
circ that circulates the water in this tank through a solar panel in the summer, or through an external coil wrapped around the 2" pipe of the "primary" boiler loop in the winter. It is not at all critical to my hot water supply but tempers the 52 degree well water feeding the indirect. Most days in the summer the "tempering" tank temperature is around 75 degrees by sundown; in winter it is generally 80-90 degrees most of the time (drops off after a couple of showers but bounces back in a couple of hours). It cut my summer fuel oil bill in half and cuts the heating load on the wood boiler in the winter.

 

[tom in maine]

You guys are missing the point. He already has the heat pump and tank. The question is about the piping size. 1/2" is fine.

 

[mustash29]

I almost have a Nyle. Apparently it spent about 24 hrs taking "merry-go-round" rides on the conveyor belt sorting line in Wallingford today. LOL. Supposed to be here tomorrow.

I already have an 80 gal indirect. Someone ordered a new one but wound up just having a leaky fitting on their tank, so I got it at cost. Due to the slower recovery of the HP, I wanted a big tank anyway. The Nyle will be adjacent to the tank and above the boiler storage tank, so any waste heat will be scavenged from the basement.

My storage is less than I would prefer, due to limited basement area, so letting the Nyle handle DHW will extend my boiler storage capacity.

Letting the Nyle handle DHW will allow me to take a little more time to plumb the wood boiler, storage & re-configure the oil & loads into a better pri / sec set up. My original plan was to let the wood keep the oil in hot standby but I decided to go pri / sec instead, again due to limited storage volume.

Thanks for the votes for the 1/2" lines, I already have a mix valve and 1/2" pipe.

 

[JP11]

I have this exact setup. My indirect is a 80gal buderus horizontal that the oil boiler sits on. I can't help much, as I installed the Nyle this fall. I used 1/2 to connect to the Nyle, and it worked fine in testing. I figure with just my wife and I, the 'slowness' of recovery on the Nyle is offset by the large amount of storage.

I have 1k gallons of storage, so I gave up on the Nyle as soon as I started burning. But looking forward to spring and going straight electric. Solar panels powering it.

JP

 

[mustash29]

My shack sits in the NE corner of my lot. Most of the south & west is heavily wooded. If I take out the huge, tall leaf makers I will get a better view of the sky.

Solar PV is a definate future possibility. It would really help with the summer A/C bills, and my wood boiler has 4 ports on it that accept standard 4500 watt electric DHW heater elements. PV, grid, wood or oil will provide plenty of diversity for future market fluctuations.

 

[mustash29]

Tom,

Thanks for the opportunity to do business with you. The Nyle has arrived, boxed & strapped to a nice little shipping pallet, all in good condition.

 

[tom in maine]

Thanks. That is good to hear, sometimes Fedex does bad things to heat pumps.
Contact me if you have any questions.