Lochinvar KHN85 vs HTP UFT80 (really Westinghouse)

Gman66

Planning my boiler replacement and need to choose between Lochinvar and Westinghouse/HTP.

2900 sqft house in Northern New Jersey. Heat loss of 63K total, 38k on first floor and 25K on second floor. 80ft of finned tube baseboard on first floor, 70 ft on second floor. Baseboard tubes are all 1/2". Two zones; one for first floor and one on second floor.

Both modcons have 10:1 turn down. Quick internet search suggests $1,700 for Westinghouse, $3,300 for Lochinvar. I believe Lochinvar has a circulator while Westinghouse will need one (advantage as I can getting a delta P circulator).

Plan is to pipe direct like current cast iron non condensing boiler. I think both of these boilers can work piped direct. I will also add an indirect for DHW (perhaps a reverse flow Turbomax but not sure yet).

Boiler will be in unfinished unconditioned walkout basement (about 1/3 of basement is above grade, 2/3 below grade).

Trying to figure out if $1,600 premium for Lochinvar is worth it? I guess the included pump closes the price gap a little.

Paul48

I'm not a pro, but I'd save the money and put it towards adding emitters, to get the supply temps down and keep the boiler condensing.

hot_rod

80' of 1/2 fin tube on one loop?

Paul48

Ooops.......I missed that hot rod. He definitely needs to do some work on that end, or a mod/con is a waste.

Gman66

hot rod said:

80' of 1/2 fin tube on one loop?

Each of the zones has two loops; one front of house, one in back. First floor front of house loop has 43 ft, while back of first floor has 37 ft. I current see about 27 delta T on the first floor zone on the really cold days.

80 ft on 1/2 tube would have really big delta T!

Paul48

Those DT are at 170-180 degrees. Those temps won't cut it for a mod/con to condense, even at design temps.

hot_rod

There is a bit of difference between the two heat exchangers when you compare them. That Lochinvar design has been around for 20 years or more.
The Lochinvar has a bit more functions on the control, if that is of any benefit.
The ramp delay and boost functions are nice for dialing in the boiler to the system.

If you don't need or want those features...

Gman66

Paul48 said:

I'm not a pro, but I'd save the money and put it towards adding emitters, to get the supply temps down and keep the boiler condensing.

My estimate is that below 50% of design day load I should be condensing; not the most efficient system around, but better than my current 30 year old ci boiler. My current boiler has been wonky since I moved in 16 years ago (125K btu input boiler cycles even when aquastat set at 190 degrees while supply temperature with both zones running will only get to 170 - more water through boiler lowers supply temp even though it is cycling) so time to replace.

Gman66

Oh, before I forget, thanks Paul and Rod for quick responses. This forum has the most helpful gang of participants, better than any forum I have read!

EzzyT

At design you can run that baseboard at 155 degrees With outdoor reset during the shoulder months you could be looking at as low as 120 degrees that of course is if your heatloss is at what your saying it is.

Paul48

Is the output of 1/2" that much better that 3/4" EzzyT?

EzzyT

Those numbers are based on 1gpm doesn't matter if it's 1/2" or 3/4" the only thing that changes between the two is the headloss.

Paul48

OK.....His first floor is at 165 at design. His 2nd floor is slightly over-radiated and would be less.

EzzyT

Correct, kinda hard to say how much condensing a mon/con will be doing on a system like this one. But the modulation of the boiler will help a bit.

Henry

Here in the Great White North, our heating season is 1050 hours of boiler operation. Of this only 200 hours are at maximum design temperature. The rest of the time, a mod/con works very well. Even at 180F most mod/con have around 87% combustion efficiency.

Rich_49

You should not purchase the Westinghouse model ! Although it is the same unit when you need support you will not get it from any local wholesaler or HTP Factory Reps . The boiler costs the same money from your local wholesaler , give or take around 100.00 .

Contemplate using a manifold with actuators and a homerun to each of the four supplies and returns to keep flow up a bit and use a Delta T circ ( Taco VT2218) . It will adjust the flow and head and avoid that 27* Delta thing and get some comfort along with avoiding any lower flow issues

Gman66

Rich said:

You should not purchase the Westinghouse model ! Although it is the same unit when you need support you will not get it from any local wholesaler or HTP Factory Reps . The boiler costs the same money from your local wholesaler , give or take around 100.00 .

Rich, thanks, sounds like good advice; I may be cheap but a few hundred dollars to make sure there is some support down the line seems like a good idea.

Rich said:

Contemplate using a manifold with actuators and a homerun to each of the four supplies and returns to keep flow up a bit and use a Delta T circ ( Taco VT2218) . It will adjust the flow and head and avoid that 27* Delta thing and get some comfort along with avoiding any lower flow issues

This is the downside of the 1/2" piping. My plan is to have circ on boiler supply branching to two zone valves which then branch to two loops for each zone. Each loop will have a butterfly valve for balancing. This is all near boiler piping in the basement. Each of the loops comes back to the far side of the basement where they tee back together on a 1" manifold for the 45' ride back to the boiler. I am going to use Taco Accuflo balancing valve so that I can measure loop flows with manometer when the spirit moves me. What is the practical flow limit on a 1/2" loop? Will push that through the downstairs loop with the most emitters to minimize DT. After reading Hatterasguy's adventures with DT circ, I was leaning toward DP circ to keep flows relatively constant w/ 1 or 2 zones open. I guess a DT circ would increase flow just when needed to keep near design day DTs down, but worried about what happens during low demand days. Seems a 20 degree delta T on low load would result in almost no flow.

Rich_49

A Caleffi Manifold or others will allow you to adjust individual loop flows and will also go a long way to avoiding an issue like the one you mention .

At present you state you have a 27* Delta . Worrying about low flows at a 20* delta sounds kinda silly .

What goes into a tee must come out of a tee . That 1 x 1/2 x 1/2 tee is oriented how ? Is the highest head circuit off the bull or run of the tee . Makes a difference in how each will perform . The manifold takes that wild card out of the equation , each loop or circuit can be adjusted for comfort .

Taco does also make a more versatile Pressure pump than any other , if you want to go pressure circ try the VR series , more range than any other . The VT works just fine with the UFT when using manifolds as the head is a bit higher and you are not as much a slave to pump laws oft forgotten about by most if they ever knew they existed to begin with .

NY_Rob

OP- have you looked into local repair support for the HTP?
You may be in for a unpleasant surprise if you have problems with it and none of the local's will support it. Is your installer willing to offer repairs down the line?
Lochinvar has a pretty well established local support base in many areas.

Paul48

Hmmm....who do we know in NJ?

Rich_49

Plenty of support in NJ . North Jersey , Ezzy T , Emerson Swan has great support there , matter of fact their head guy Mike Oppel is in Hudson County .

Fear monger much NY Rob ?

Gman66

Rich said:

A Caleffi Manifold or others will allow you to adjust individual loop flows and will also go a long way to avoiding an issue like the one you mention .

At present you state you have a 27* Delta . Worrying about low flows at a 20* delta sounds kinda silly .

I think I finally understand your suggestion for Manifold with electric actuators. I assume I could gang two actuators together for each thermostat. I also assume I don't have to have the supply manifold right next to the return manifold such that I could leave the return on the far side of the basement.

As for my 27* delta T, this is a result of 40 ft of emitter on loop w/ and estimated 1.4 gal flow on design day. I mentioned above (but I am sure it was not clear) that I have to restrict the flow through my current boiler or the supply temps fall off. With the flow restricted down to estimated 1.4 gal per loop, I can get supply temp of about 175* with aquastat set at 190* with one zone open. If the second zone opens the supply temp will fall another 10*. Note that the burner will still cycle; the aquastat well is clearly in a hot spot while the flow out the supply is much cooler. I am sure your natural inclination is that the aquastat is bad but I have replaced that with no change years ago. I have also run in manual mode (aquastat is Honeywell 8148J with millivolt gas valve) and gravity circulation w/ zone valves manually opened and the supply temp matches very closely the aquastat and temp gauge on boiler. I have no way of measuring loop flow; I am estimating based on supply temp, delta T and length of emitters, I could be off by a lot, but fact remains I am restricting flow. If can flow 2 gal per loop my delta T should get close to 20* on design days.

Rich_49

The manifold will give you the ability to adjust flows while you watch the S & R temps on the display on a VT2218 . One loop at a time , get it where you want it with the flow meter on the manifold and set up the circ to maintain your desired Delta T .

I would leave the return and supply manifolds at the same location , remove the common 1" pipe and replace with 2 home runs . I would like to know how many emitters on each circuit , are they first floor , second floor . Do you have a room by room heat loss done and how many feet are in each room ? There are lots of potential opportunities to do this well and possibly spend better . Need to know more information though .

Gman66

BTU Heat Loss using Slant Fin (I know, not the best). Emitter Ft as measured. I used a 67* Indoor Temp and 0* for Design Day (I am in Morristown NJ). I have included the existing loops (4 loops in two zones; each floor is a zone) and the order of the rooms in each loop are the order of flow (supply >> return). Slant Fin is giving me numbers a bit different than my recollection from a year ago when I ran each floor as one big room (I don't recall the program I used and I likely guessed at windows instead of measuring like I did this time). 39.8K for the first floor feels a bit high given the emitter length and the supply temps and Delta T that I currently see on really cold days (supply temps cycle up and down but can't average better than 170*).

= BTU = Emitter Ft
Total = 61,973 = 154.5

Floor 1 = 39,767 = 78.0

Loop 1 = 24,578 = 46.5
Office = 5,355 = 14.5
Laundry = 1,990 = 5.0
Kitchen = 6,971 = 7.0
Powder = 831 = 4.0
Family = 9,431 = 16.0

Loop 2 = 15,189 = 31.5
Living = 7,567 = 16.0
Hallw = 2,660 = 4.0
Hallw = 595 = -
Dining = 4,367 = 11.5

Floor 2 = 22,206 = 76.5

Loop 3 = 8,422 = 29.5
MastBa = 2,734 = 9.0 Includes 7' for Kickspace
Bath = 1,254 = 4.5
Bedr 3 = 4,434 = 16.0

Loop 4 = 13,784 = 47.0
Mast BR = 5,571 = 20.0
Bedr 2 = 3,228 = 13.5
Bedr 1 = 4,491 = 13.5
Hallw = 494 = -

brucewayne

i think ibc makes best mod/con boiler, better than htp, better than all of them.
the least problems and great warranty.

keyote

Just installed my KHN 085 piped direct my radiant temps and flows are low but it works well,Its an awesome machine

Tinman

@brucewayne - So you've installed Viessmann, Lochinvar, HTP, NTI?