Installing HTP-UTF 80

DAVIDSEIDEL

Installing the HTP-UTF 80 soon so I have some questions. Manual J load comes in at 35.8 kBtu/hr.
There are 11 loops in the concrete 4" slab on grade over Ampex panels. All loops are 260 - 290 feet.
I want to add 2 more loops to heat the bonus room above the garage that will have to over come a delta of just 20 degrees because the garage will be heated to 50 degrees. I will use aluminum reflector panels to radiate the heat into the floor/air space/ insulation.
So....... 13 loops. Zones will be 4 loops, 5 loops, 2 loops garage, and 2 loops bonus room (diff emitter).
I want to use Primary circuit with a Grundfos Alpha2.
Can I set up the bonus room on a separate thermostat that opens the zone loops up but does not fire the boiler. Then, when any of the other zones turns on, that room will get heat as well.
Trying to avoid short cycling from that zone.
Also, because of 13 loops (cannot find a manifold) unless I want to spend big bucks, I bought a 6 zone and a 7 zone that I want to use and pipe like the attached pic.
4 loops and 2 loops on a manifold. 5 loops and 2 loops on the 2nd manifold.
Anything wrong with current plan?
Thanks, David

DAVIDSEIDEL

Forgot, that bonus room is entirely inside the envelope of 6" sips wall and 12" sips roof panels.

Gordy

Keeping your zones with in the lowest modulation (8k) with that boiler is beneficial to avoiding short cycling.

Edit: That being said your total load is 36k. So with out noting the loading per zone it's your call. Just remember that load is at design conditions which isn't much of the winter season. So the rest of the winter is above design. This will be where short cycling shows it's ugly head.

GroundUp

I would not bullhead the tees if you decide to split the manifolds like the picture you shared. You should feed the run of a tee and split the branch and other run, not feed the branch/bull. As for the extra 2 loops wiring ordeal, just wire the stat directly to the the actuators with an external transformer, skip the switching relay altogether on that zone. I feel like the garage is likely still going to short cycle the boiler on warmer days only being 2 loops. Buffer tank an option?

Ironman

I'd recommend a buffer tank or combining some of those zones, or both. The cost of a buffer tank will be far less than the energy wasted and the shortened life of the boiler.

You can use an electric water heater for a buffer tank if you wanna do it cheap or HTP has a SS 30 gal. buffer that's reasonably priced.

DAVIDSEIDEL

Here is the loop plan layout, South is at the top. 14' X 14' sunroom. Garage lower left, craft rm next to garage on South side, 2 bdrms/bath rms/ laundry right.
I figured 5 loops for main house, sunroom, craft room.
4 loops for the 2 bdrms, bathrms, laundry.
2 loops garage, 2 loops (bonus above garage) differnt emitters.
I there a better way to combine loops? Zoning?
Thanks for the help,
David

DAVIDSEIDEL

I believe I can use a buffer tank, Utility room will get tight, and I will plumb as suggested, feed the run of a tee and split the branch and other run.
Keep the help coming....... I need it.
David

DAVIDSEIDEL

Reading about these buffer tanks and DHW. Now I need to know how to set up Indirect DHW/buffer tank. That looks like the answer.

NY_Rob

No real downside to using a buffer tank, and the UFT has provisions for the primary pump right from the factory.


The Alpha seems like a good choice for the primary pump. One of the fixed speeds will work. Looking at the Alpha's curve chart- fixed speed 1 will give you 6gpm at 2ft head which is almost a perfect match for the UFT 80's HX curve chart.

hot_rod

Reverse indirect tanks can be used to buffer also, so you get buffer and DHW from one tank, a space saver sometimes.

Thermal 2000 builds tanks for this application

Gordy

cant read the loads for each zone on your post. Pertinent if you want help condensing.

Gordy

NY_Rob said:

No real downside to using a buffer tank, and the UFT has provisions for the primary pump right from the factory.


The Alpha seems like a good choice for the primary pump. One of the fixed speeds will work. Looking at the Alpha's curve chart- fixed speed 1 will give you 6gpm at 2ft head which is almost a perfect match for the UFT 80's HX curve chart.

Yes there is a downside. Extra cost be assured. However if the indirect is in the picture then the ones @hot rod posted are at least a double duty peripheral, and not another turd to polish in the boiler room taking up space.

DAVIDSEIDEL

Not sure if this will help or is even correct......seems high.
20 btuh/sq ft.? This is the Great Room

DAVIDSEIDEL

Room 2 is the garage.

Ironman

DAVIDSEIDEL said:

Not sure if this will help or is even correct......seems high.
20 btuh/sq ft.? This is the Great Room

That sounds close.

DAVIDSEIDEL

OK, i am making progress thanks to all you fine guys.
Picked up the Thermal 2000 TurboMax 33. Luckily, I got it locally.
So now my questions are, what temp do I run the TurboMax at?
140, 150, 160? Will the HTP UTF 80- condense good, effeciently at those temps?
And can I now run smaller 2 loop zones without issues?
Thanks!
David

NY_Rob

Condensing will depend on the return water temp... keep an eye on it. 130F is the beginning of the condensing range.

Ironman

No boiler will condense when the water temp is 140*+.

This is where the ODR curve needs to be properly set in order to let the boiler condense as much as possible, yet not let the water temp in the tank fall below what's needed for domestic. Probably not below 115*.

hot_rod

DAVIDSEIDEL said:

OK, i am making progress thanks to all you fine guys.
Picked up the Thermal 2000 TurboMax 33. Luckily, I got it locally.
So now my questions are, what temp do I run the TurboMax at?
140, 150, 160? Will the HTP UTF 80- condense good, effeciently at those temps?
And can I now run smaller 2 loop zones without issues?
Thanks!
David

With a cold indirect load, the delta will be high when the boiler first fires, so return will be low and it will condense even with 140F supply. As the tank warms the delta closes and return will warm up and may fall out of condensing mode. Try the lowest temperature that still provides adequate DHW.

This type of tank store energy in the boiler water and the large copper coil area makes it an instantaneous DHW heater of sorts.

So it really will come down to how much, how fast, and how hot you want DHW. Some trial and error to get it dialed in to you exact needs.

Maybe there is a way to let the boiler go to DHW temperature under a high DHW load, suppling 180F or more. You would need to measure DHW temperature drop and let the boiler rev up. I doubt you will need to get that interactive.

TurboMax may show DHW output at different tank temperatures on their site?

Gordy

Agree with @hotrod_7 there will be a period of time in condensing mod when charging the turbo max until closing in on setpoint.

Once you are up and running you could experiment with capping out upper modulation if possible, and charge the indirect low, and slow.

At 60% modulation your at 89% efficiency. Still not bad. If your dhw demands are not high. Running 60% your at 48k still more than a conventional water heaters output, and much higher efficiency.

DAVIDSEIDEL

Progress.

DAVIDSEIDEL

Trying to figure best way to get my 2" (closed space Tee) at the buffer tank. No matter how I do it, it is more than 4" from that tank. The outlet pipe alone is sticking out 3".

hot_rod

A couple 1-1/4 X 1 X 1 black tee would be easy and less$$

adapt to 1" copper to boiler and loads.

D107

Are reverse-indirects acting as buffer tanks harder to keep at the 140ºF temp to avoid Legionnaires bacteria than regular indirects?

hot_rod

David107 said:

Are reverse-indirects acting as buffer tanks harder to keep at the 140ºF temp to avoid Legionnaires bacteria than regular indirects?

Not sure what you mean by harder? They have a large heat transfer surface area so running the boiler SWT a bit over 140F should give you good DHW production. I think TurboMax has a graph showing performance at different SWT and flow rates.

With a mod con, you really don't want to run the boiler and tank at 180F or efficiency goes down. Balance adequate DHW, heat load and lowest possible SWT.

D107

I guess I was thinking that with a Turbomax serving both as buffer and hwh, those two tasks--with the added draw--would tend to bounce the tank temp up and down more. Which would mean that the 140 temp would not be maintained for the duration of time required to kill the Legionnaires––whether mod-con or CI.

DAVIDSEIDEL

I was stuck on getting it to 2".
So, going with the 1 1/4" Tee, should I have a union at the tank first?
Thank you for the advice!
David

hot_rod

no need for a union unless you expect leaks With 6 gum flow as Rob indicated above, 1-1/4" should be plenty.

Gordy

So long as the tank sees 140 for a good period of time you should be fine as far as legionnaires is concerned.

hot_rod

> @David107 said:
> I guess I was thinking that with a Turbomax serving both as buffer and hwh, those two tasks--with the added draw--would tend to bounce the tank temp up and down more. Which would mean that the 140 temp would not be maintained for the duration of time required to kill the Legionnaires––whether mod-con or CI.

> @David107 said:
> I guess I was thinking that with a Turbomax serving both as buffer and hwh, those two tasks--with the added draw--would tend to bounce the tank temp up and down more. Which would mean that the 140 temp would not be maintained for the duration of time required to kill the Legionnaires––whether mod-con or CI.

supposed to be 2 hour at 140F for legionella protection

The trickey part of legionella is it grows in the sediment in a tank and it’s tough to kill there

with a reverse indirect the water is in the coils not the tank. That may lessen bacteria potential

Or raise the tank once a day to 160

I think 15 minutes at elevated temperature meets codes in countries where legionella codes exist

DAVIDSEIDEL

Do I need unions at the boiler or is that not necessary?
Also, I have shut off valves with purge on the pump flanges. Do the purge ports go upstream or downstream of pump?
Where do I need shut off valves besides at the boiler?
Thanks again, David

hot_rod

I don't use a lot of unions, unless you expect to remove components often, they are just more leak potential. Iso valves on both sides of the pump.

One Webstone purge valve on the bottom of the tank, return from the system. This one valve allows you to purge the entire distribution system.

GroundUp

I like unions on the boiler, but I also tend to cram everything in tight so if there should happen to be a necessary repair someday there is no "cutting in" a new fitting. More than once I've had copper elbows crack down the heel seam weeks down the road and I sure hate having no way to repair without starting new. The purge flanges aren't often useful in pressurized radiant systems, but seeing as you already have them, I vote downstream for no other reason than purging the air from a new pump without introducing it into the system

SuperTech

Put shut off valves on the expansion tank, fill valve, air vents, circulator and any other component besides the relief valve that might fail. Adding fresh water to hydronic systems is something that should be avoided. And you will thank yourself every time you find the expansion tank water-logged.😉

Valves are good and unions can be useful too. I have several in my house that haven't leaked, but they need to be tightened with Hulk strength.

DAVIDSEIDEL

More progress. I need to sweat the primary pump line yet and finish expansion tank......it is just screwed on for picture.
Do I need the check valves in the pumps?
I don't think I do, but not sure.

DAVIDSEIDEL

Another picture.

Ironman

It looks your pumps are in series. They need to be in parallel, and they need check valves.

Henry

You can have one pump from the top to feed the radiant and one from the bottom connections for DHW. If piped as the manual, no check valves are required.

Ironman

I just looked at the pic without remembering the rest of the thread. He's using the indirect as a buffer tank.

Ironman

@DAVIDSEIDEL,
I think you're gonna have problems with either the slab overheating or your domestic being too cold depending upon where your reset curve is set.

Notice in the diagram that an injection bridge is used and its pump is controlled by a Tekmar 356 which works off of ODR.

A slab normally needs about 75 - 100* SWT to prevent it from overheating. That's too low for domestic, so the tank would need to maintain a higher temp.



@hot_rod7
How would you advise?

DAVIDSEIDEL

Ironman ,
Would I need a third pump? Controlled by the tekmar 356? Getting very frustrated.
Thanks,
David