HTP-UFT Boiler

Paul48

Hat........Considering you are going to add some head to get the flow rates down, how about an inline flow meter?

ricking

Any updates on the HTP UFH installs?

hot_rod

4Johnpipe said:

The UFT is called a mid mass heat exchanger...Sent a few almost done pictures of this job to Rich. We will be back to do a final combustion analysis this week and see if we need to tweak anything...Sure would be nice to get a little cold weather here soon.! Will get some better completed shots then also...

A good step in the right direction, with the UFT.
I'd like to see a bit more mass and or water content. I'm not sure the definition of mid-mass?

This Viessmann product seems to hit that mid mass in my mind 13- 18 gallons, 270- 350 lbs, 40∆T possible.

Gordy

Mass can also be the hX material in itself. It seems the V HX is a modified version of the tried, and true.

Someday I would like to see the cut away on the UFT HX. medium mass can be a broad term in comparison to water volume of other brands of similar size. 3.5 gallons for all UFT versions verses 2.5 on up depending on Gross input.

In the end the V is just adding on board buffering with no attempt to get the lower end modulation down. Is it structures, and zoning habits across the pond? Is anything over a 5:1 TDR a waist in their eyes.

I know a lot of old,structures have to stay historical with very little up grades. Mostly stone, concrete, and Brick.

hot_rod

Hatterasguy said:

5:1 is fine if the boiler is well matched to the heatloss.

But, once you need to make hot water.....................

Then again, the two five minutes showers per week mitigates that need................50K would be fine.

In reality, we could also make do with a UFT-50 if a big indirect was utilized.

Or cut the Pioneer in 1/2!
Make a true mid mass 25 gallon tank/ boiler. Now you have a boiler that can operate at zero flow, and would be fine with just 5-1 for most residential applications. A proven 100% stainless tank design.

It closely mimics the cast iron boiler that worked perfectly fine under low or no flow conditions, for around a century. Which is what it appears all the boiler manufacturers are sneaking back to with higher fluid contents. But now we have state of the art microprocessors to drive and modulate them efficiently.

Maybe the RAY boiler was not so exotic after all, a condensing cast iron boiler? They may outlast the sheetmetal thickness stainless HX boiler designs we now see.

Paul48

Modulated / gravity?

Paul48

So far, it appears as though the UFT is as close to plug-n-play as you can get, because of its minimum flow. Look around the "wall" and see what people are having to do, to get their systems running efficiently. It's about time that all the manufacturers wake up and smell the coffee. It's not like they didn't know there has been flow issues. They can't claim they didn't know about the whole, buffer tank culture that has cropped up.

Gordy

IBC knows. Read their manual. The only one who addresses the need for buffering in their manual.

Paul48

I see that as them recognizing their failings.

Gordy

Well yes in recognizing a deficienciy in their design in certain scenarios.

Let's face it a buffer tank was just another piece of hardware for those situations when the boiler did not fit the heat loss, or zones did not match low end modulation.

A Rag to polish, and refine their product. It was/is excepted practice everyone just did it, and added capital cost to the system passed on to the owner. The installer got paid, and the guy selling buffer tanks, and the guy who made the boiler that needed it.

Everyone's happy except the owner who paid a lot for that muffler. Pretty soon the installer gets less work because his systems are costly compared to the farced air guy. He can't compete. Pretty soon less buffers are sold, and boilers. Then it's time for change. Manufactors do listen, and change, but not until they have to........the time has come. Plenty of white papers blowing the efficiencies out of the water. Time to refine.

Paul48

Kinda like, providing a bigger hammer to make a square peg fit in a round whole.

Gordy

Pretty much. When the masses use the tools they are given, and don't complain. No one makes,the square hole, or the round peg. Especially when they sell.

Gordy

Maybe some will take notice of the sudden up roar the last couple years......some I mean one already has.

ricking

Hopefully they will make one a little smaller. My heat loss calc is around 40-45k and the and the UFT is 80. Even though it downs to 8 , I think it is still too big. Maybe I'm wrong. I hope.

ricking

I just wish there was some guys like you in my hood that could have a look see and and install the proper system.

Rich_49

I have said this in the past and still say , you cannot oversize a modcon . The low end is where they are problematic and the oversizing issue only comes into play where the low end is not low enough . The oversizing really accomodates DHW production with an indirect or a flat plate .

Since these discussions have taken place about the direction that must be considered and taken I say that the 80 is good . If you only ever use 50% of the capacity it does not cause any harm . It only allows us the capability to guarantee good . comfortable heat at below design conditions . Boy , that sucks huh ? The whole mindset has to change , the manufacture community has given us nothing as a whole and it is up to us to re learn and really evaluate what we do and what we have been given .
As far as the V is concerned , all that 13 gallons and the best they could do is 19K on the low end ? Warning , there are other boilers like the Laars that will appear to be identical to UFT , using same HX , same control , it is not . The difference is in the gas venturi that HTP uses .

Making a Pioneer smaller would be a feat . It would no longer be a Pioneer since the same HX could not be used , possibly that could get smaller also to make such a thing possible . Not sure less water really does alot of good as the capacity presently can be used to our advantage . Remember , a buffer can be not large enough but it can never be too big . The most efficient boiler is the one that is idle . Suddenly leveraging storage is bad , why is that ?

Rich_49

Since HTP has this new gas venturi maybe they will incorporate it into some other units assemblies . Maybe the Pioneer too could get a more generous TDR ? Interesting .

njtommy

Could you imagine the pioneer with a low tdr of 5-10k?
55 gallons of water.
It could literally sit and run all day at 5k btus on a constant circulation system.

hot_rod

Hatterasguy said:

hot rod said:

Or cut the Pioneer in 1/2!
Make a true mid mass 25 gallon tank/ boiler. Now you have a boiler that can operate at zero flow, and would be fine with just 5-1 for most residential applications. A proven 100% stainless tank design.

I had grand visions of using the Pioneer before the UFT arrived.

There is one looming problem:

You cannot make hot water with it. If you want to stay with lower water temps and not store high, no HW for you.

The alternative is to store high and mix down so you can produce HW on demand with an indirect (or with an external HX as you have done and I had planned to do).

The addition of the mixing valve tends to tip the scales in favor of the low (or "mid") mass boiler that can make hot water on demand when it offers up such a huge turndown for CH.

Just wish they made a UFT-60.

You can easily get a 3-5°approach with a flat plate HX.
How hot do you want your DHW? If you want 120F, as most codes limit residential system, then a tank with 125F, at the top, would give you adequate DHW. Return to the bottom of the tank at 115F, if you want a 20∆ in your system.

If you DHW needs are around 103- 105 for showering and washing, etc, better yet. since you are not storing any DHW in a tank to legionella concern isfa

Most tanks have upper and mid-point connections, as long as you have 130K input you should be able to generate 3 or so GPM instantly from the Pioneer with adequate HX and circ..

Zman

@hot rod I sent you a PM, did you get it?

hot_rod

Zman said:

@hot rod I sent you a PM, did you get it?

Nope, I don't think you are getting mine either?

hotrodradiant@me.---

motoguy128

Just reviving this thread. I'm purchasing a home with a 15 year old 80% furnace and AC and gravity vent tank water heater. Its on private water and suffers from typical anode rod induced H2S odor. I'd like to have a single direct vent appliance and I'm seeing too many limitations and negatives on combi's. Plus the small passage flat plate heat exchange even with softened water is probably a really bad idea. I'll be cleaning in 2x a year I bet.

I'm thinking A UFT with indirect. Either 100 or 120k to shorter DHW cycles so the space heating interrupt is less. Plus it's a small increase in price, and efficiency on low fire is better. I also might add a tube & shell in the future for a hot tub plus maybe a 4 season room with radiant.

What I only saw mentioned, was the mid mass aspect of this boiler is impressive. I don't know why it's mid mass no high mass, because the 3 gallon water volume is almost equal to most cast iron boilers. Iron holds a lot less heat than water per lb, so despite the 200# HE in those beasts, they don't add much thermal storage and without modulation, they will still short cycling below 50% load.

With the UFT would could run even the 120k model with a 9k BTU load, and that 3k excess after factoring in 94-96% efficiency, will take around 8 minutes minutes to raise the 4 gallons in the HE, coil and piping by 10F. So realistically, if I install it as I plan with 2 stages using 2 blower speeds, the system will run almost constantly unless I use the boost feature. I actually could set the ODR a little low, and lean on the boost feature to bump it up a little and make-up for DHW calls. Current heat loss estimate is 40-50k just looking at typical construction and comparing it to my current home. I need to get utility bills and run HDD numbers to get some better numbers.

I might need to contact their engineering dept. to see if you can do unbalanced venting or concentric using a 5" chimney. Thinking dropping a SS liner will be easier than gluing PVC up on a roof.

Any thoughts?

Rich_49

http://www.htproducts.com/poly-pro.html

Gordy

You can use the uft, or any other boiler for that matter IF you fill the system with an exceptable water source. It's done a lot that way. RO comes to mind.

hot_rod

Gordy said:

You can use the uft, or any other boiler for that matter IF you fill the system with an exceptable water source. It's done a lot that way. RO comes to mind.

It is rare to fine suitable water on most any job sites these days, pay attention to what the boiler spec calls for, they are really tightening up the water quality requirements.

Check the ph if you use RO water, it tends to be a bit lower than what the manufacturers like. Buffer it back up or use a hydronic treatment with that pure water.

DI is another way to "clean" up the water without ending up too aggressive, it is much faster and cheaper than true RO water to produce on the job site.

This Thursday, noon central time we have a free 1 hour webinar on water quality. Last I checked we had over 400 sign ups, it is a hot topic in the industry now.

Coffee with Caleffi

motoguy128

Good point about water quality. Shouldn't be any leaks after initial fill. So if I can do the primary fill using a funnel from a high point and add boiler chemicals, then just use the domestic water to add the last few ounces to pressurize, I should be OK, I'd think. But doing some water quality testing is a good idea. We also might just bits the bullet and connect to city water and use the well for hose bibs and lawn irrigation only. City water is from Lake Michigan, and near the end of the system so chlorine levels should be a little lower too but sediment could be higher.

Great points.

I've seen those Duravent kits. Looks easier and cheaper just to use SS flex down the existing B vent and just cut a 3" hole in the top the the existing weather head and use it as the intake making it concentric. HTP doesn't specifically list concentric like Lochinvar and other do, but if there's an issue I'll just revert to non-direct vent. But I don;t see why it would so long as it's within the range of static pressure that the inducer can handle. With about 40' equivalent of 3" exhaust, doubling that for intake, it will be at 80', still under the limit. I can vent sidewall through an enclosed crawlspace if needed, but I don't like sidewall venting. Rather have flue gasses vent out up high all year long.

hopscotch

what happens when the inlel and outlet are hooked up backwards on a htp uft 140 boiler

Zman

This would be better as a separate post.
In that post a picture would be helpful. If you truly pipe the boiler backwards, most mod cons will error because the supply and return sensors will be confused.