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Community and Q&A

HTP Phoenix Light Duty paired with Lifebreath Clean Air Furnace (downdraft)

stk | Posted in Mechanicals on

I want to replace the atmospheric water heater (interior to my house) with sealed combustion. I also wanted to replace the 80% furnace that sits right beside the WH interior to the house. I learned early from GBA that inside combustion is to be avoided.

Fast forward…I am looking at the HTP Phoenix Light Duty + Lifebreath CAF (downdraft). I am in the Seattle, WA area in a 1950’s rambler.

1. Does this seem like a smart solution? Would you recommend other configurations to consider? I did not see much on downdraft air handlers…are these generally site-built? I have existing forced air ductwork, but no need for A/C.
2. Any leads on a good consultant or installer in the Seattle area? Of course the companies that deal with HTP and Lifebreath are different and I am really concerned about installer experience and warranty support.
3. I am about to get the unconditioned attic air sealed and insulated and I was hoping to get any new PVC venting installed before that work gets done.
4. I read some stuff online about a problematic install for a Westinghouse-branded HTP unit down in the SF Bay Area. Any word on the street regarding Westinghouse vs HTP. The big box store has the Westinghouse-branded units on sale this month.

I also have a 15K BTU Mitsubishi ductless, but getting family complaints about cold rooms. Keeping doors open is not enough. The air sealing and insulation may get it to the point where the ductless will be sufficient, but I need to change the water heater soon regardless.

Thanks for any help/insight!

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  1. GBA Editor
    Martin Holladay | | #1

    Choosing equipment is only a small part of the design of a good system.

    Step one (as we say often here at GBA) is a room-by-room Manual J calculation to determine your design heat load. Once that work is complete, it's possible to think about equipment selection.

    Even if the equipment you have identified is a good selection, your system will need a good duct design and a contractor who is familiar with the equipment and skilled at installation. Without those, you may be dissatisfied.

    By the way (note to GBA readers): The Lifebreath Clean Air Furnace is mis-named. It's an air handler (used as part of a hydro-air system), not a furnace.

  2. stk | | #2


    Yes, I hear you. I just don't feel too great when asking a contractor to propose on this kind of system. Most all want to just sell me the standard discouraged me from anything but a standard water heater. From what I can tell, hydronics are a sideline for most companies and the few I see that specialize, do boilers/radiant and don't carry the HTP product.

  3. Expert Member
    Dana Dorsett | | #3

    First off, if you have a heating history when heating with only the 80% efficiency furnace run a fuel-use based load calculation. If you only have ductless + furnace data to work with it's more complicated, but still possible to estimate the contribution from each, if you can give us the model of the ductless. See:

    With a fuel use load calculation you can sanity-check any Manual-Js or proposals that come in. The ideal system is no more than 1.4x oversized for the heat load at the 99% outside design temp, but you'll find most hot air furnaces out there have more than twice that for an oversizing factor, which is noisier and less comfortable than right-sized ducted systems.

    The Westinghouse unit and the HTP are exactly the same under the sheet metal, and some Westinghouse documentation even refers to HTP part numbers. It is manufactured by Kiturami (a tier-1 Korean boiler design & manufacturing company) for export under the generic name "HomSys". Kiturami also makes boilers, combis, and tankless water heaters for Laars, and Noritz, among others, and has a decent market share for all of the above in the Korean residential market.

    Pros I've corresponded with who install them for the most part give them raves. One installer in Maine who used to favor Triangle Tube's fire-tube boilers is now installing UFTs by the dozen, and another competent installer in Minnesota opted to install the UFT-80W in his own house recently.

    I'm very curious to know the details of the problem system in the Bay Area- can you provide some links to the web-discussions?

    With either the Westinghouse WRUNG 080W or the Phoenix light duty you might be better off micro-zoning with individual room air coils and heating the main zone with the ductless, rather than having to over-size the air handler to get sufficient velocity out of what is most likely a 3-5x oversized hot air furnace. That would have the benefit of no room-to-room pressure differences & air infiltration driven by the ducted air handler, and the folks who are too cold or too hot can crank it either up or down. HTP handles a line of high efficiency low-temp thin profile fan coils, but they aren't the only option out there. See:

    The VPC or VFC-14GWV fan coil delivers enough heat to not short-cycle the WBRUNG 080W, but is way more than is needed for most individual rooms. If you micro-zone the smallest of the line VFC-9GWV and using the Phoenix Light Duty (or any other condensing tank HW heater) would probably make more sense. The -9GWV put out m 4600 BTU/hr with an entering water temp of 122F (well into the condensing range for return water temps), and that's already way more than the individual heat loads of most rooms at typical Puget Sound region outside design temps.

    With a tank heater and some fan coils you can build it out piecemeal, leaving the ducted furnace in place as a "backup", but replacing the hot water heater with a condensing heater. If you only add fan coils starting with the cold rooms first you can add zones as-needed to the other rooms if the ductless still isn't keeping up. An ECM smart pump and zone valves on a manifold to the zones is probably the simplest approach.

  4. stk | | #4


    This is the thread I was referring to:

    As always, your insights are amazing to me. Many thanks for all the time to put into this and other forums! Your GBA comments also factored into my ductless selection last year, so thanks for that as well.

    In your visits to the area, have you become aware of any local folks that are good with a water heater + fan coil design/install?

  5. Reid Baldwin | | #5

    I agree that finding a competent installer can be problem. When I was choosing heating and hot water systems, I looked seriously at the HTP light duty + hydronic air handler idea. I asked the contractor to bid on that. They specified some other boiler and a price $10K more than a regular furnace. When I pushed for some explanation of cost, it came out that they were pricing in the assumption that they would have to come back a bunch of times to fiddle with it to get it working. I took that as an admission that they didn't know how to do it and didn't want to learn. I ended up with a conventional furnace from a different contractor (and a heat pump water heater).

    I also looked at the Clean Air Furnace. It is basically an HRV integrated into a hydronic air handler. As I recall, you lose the ability to set ventilation rate independent of central fan use.

  6. Expert Member
    Dana Dorsett | | #6

    I was misunderstanding it- from the link it looks like it was a Phoenix Light Duty (condensing tank water heater) that was having the problem, not the UFT/WBRUNG -080W wall hung boiler (that many installers seem to like.)

    The Westinghouse branded HTP stuff really is the same, but the support chains may vary. As long as it's installed by a competent tech it should be under full warranty and just work. The number of Phoenix Light Duty units out there isn't in the millions, but it's probably more than 10,000. This is the first instance I've heard of where it was out-of-the box dysfunctional, but it's more likely than not an issue with their installer's lack of familiarity & competence. (All plumbers with gasfitter licenses installing gas burning equipment in my area ALL have the necessary combustion analysis tools- WTF?)

    The big box store that has them on sale probably also has contractors who install them, which would put them on the hook for that part of the system. Designing a heating system around it isn't rocket science (especially with fan coils or air handlers), but it's not necessarily something many DIYers are willing & competent to handle. You can probably find somebody online who would spit out a reasonable design for you with complete schematics and bill of materials for every valve & pump, and it could be put out to bid.

    BTW: A relative of mine in Port Orchard WA just called to report that her Mitsubishi FE18 just died, halfway into it's fourth heating season. Can't blame Mitsubishi for this one though- a truck on the road 1/4 mile away took a slider on the ice taking out a power pole early Monday morning, resulting in three transformer explosions in rapid succession- all SORTS of stuff in the neighborhood smoked on that one, surge-protected or not, and the power stayed out until after business hours, so it took awhile to even discover the failure. The tech who looked at it said the dead electronics boards are back-ordered, won't be in until the end of the month, so she's down to the wood stove and resistance heat back up for now. The FE18 has performed like a champ right up until this week though.

  7. stk | | #7

    Reid, I have had similar experiences! I've come close to just replacing the gas furnace and being done with it, but I am still resisting!

    Dana, I like your idea of doing the condensing WH now and then incrementally doing the space heat later on as needed. Once I get the house better insulated and air sealed, ductless-only heat may look more bearable to the family.

  8. DIYJester | | #8

    Dana, I believe you are a EE and would be familiar with the harmonics produced in a situation as you described above. I have seen multiple industrial systems fail due to an arcing event and harmonics that wipe out the whole plant, especially solid state equipment. These harmonics and effects I would not think are too unheard off. Unfortunately, there are surge protection devices (SPDs) on all residential subs.

  9. ruffryder | | #9

    SK Any update as to how your project is going? Did you find anyone reputable to perform the work? I am in the Fall City area and have been looking for an installer similar to you.


  10. stk | | #10

    David, I finally got my first call-back this afternoon. Hopefully, I'll get an estimate within a couple of weeks and information on how many Phoenix LD units they have installed.

  11. stk | | #11

    I am still waiting on the full proposal, but the contractor is proposing an air handler made by Hi-Velocity Systems. It's a conventional hydronic air handler (LV-Z series), not a high velocity unit. The company is based in Edmonton, Alberta, Canada. Is this a good quality unit or should I ask him to consider other manufacturers? He thought the Lifebreath CAF was not worth the added cost/complexity given the relatively temperate weather in the Pacific NW. I am OK with not going forward with the Lifebreath.

    I want to stay with the Phoenix LD, but he is also going to propose an HTP wall hung combi boiler (EFTC-140W or EFTC -199W, not sure which). This is because the local gas utility (Puget Sound Energy) has an $800 rebate for the HTP combi boiler but no rebate for the Phoenix LD. I don't want to simply chase the rebate, especially as the combi boiler is presumably more expensive than the Phoenix LD. Should I be more open-minded about this?

  12. Expert Member
    Dana Dorsett | | #12

    Your instincts are right. Installing an oversized tankless and oversized air handler just to chase rebate subsidies seems like a bad deal, even if it's less money all around.

    The min-firing rate of the EFTC-140W is 28,000 BTU/hr (~26,600 BTU/hr out at condensing temps) and the min-fire of the EFTC-199W is 19,000BTU/hr in, 18,000 BTU/hr out. That means you basically can't break it up into zones without short-cycling the burner. With a Phoenix LD and local air coils sized to the room loads you have individual room temperature control, and there is no air-handler driven infiltration, no ducts to leak, and it's short-cycle proof.

  13. stk | | #13

    Well, I got the proposal back and it's well beyond my budget. I did not realize the install of just the Phoenix LD would be over $6K! I see that the sale on the Westinghouse-branded unit at the big box is ongoing through the end of March, so Plan B may take me there. Or just relocate the water heater into the garage and stay with a standard atmospheric unit. I find it frustrating to see how challenging it is to deviate from the mainstream when it comes to green HVAC improvements.

  14. stk | | #14

    I tried to get a further cost breakout but the contractor is not willing to provide more than a labor and materials split. I can't quite get to his materials number unless his price for the HTP Phoenix LD is a lot more than what I see it for at internet supply houses. I suppose most clients just pay the price and move on with life, but that's never been me. It's a tough situation to be in. On the one hand, you by definition are an "educated customer" to even know of and to want a non-mainstream product. But then you are expected to not likewise be informed on costs and other factors. I see other frustrated posts, so I know I am not alone in feeling this way. Don't get me wrong...I am not talking low-balling here. I am OK with paying reasonable costs, assuming that the basis of those costs can be substantiated. Any thoughts on what a reasonable position would be on this matter?

  15. Expert Member
    Dana Dorsett | | #15

    $6K just to install a Phoenix Light Duty does indeed seem like a gouge. If you think you know the equipment list (at least the major components) it's worth putting it up for competitive bidding. It's not a cheap water heater- a couple grand for the 50 gallon version ( ), but it's not obvious how they come up with the $4K in overhead, installation, & margin.

  16. stk | | #16

    Dana, just to be absolutely clear, the total cost is a bit over $6K. The materials cost is about $4K with remaining $2K as labor and O/H. Of the $4K materials, I had assumed the Phoenix LD at about $2500, which leaves $1500 for ancillary materials. I could not imagine anywhere close to $1500 in ancillary items, even knowing that the venting would be all new PVC.

  17. ruffryder | | #17

    S K,

    Thanks for your update on the issue. I have talked with the HTP wholesaler in the area, and it seems some of them have discussed the issue of the HTP Phoenix LT not applying for the PSE combined water and space heat rebate with the Energy Advisor at PSE. I am not sure that means as to resolving the issue, but HTP is aware and so are the Energy Advisor's at PSE.

    FYI, I purchased the 50 gal unit from Home Depot. Mine is labeled as HTP, not Westinghouse.

  18. stk | | #18

    David, I expect to do likewise and get the unit at the orange box store while it is on sale. And HTP branded to boot! I have been unsuccessful in finding an installer I trust who will install owner-provided equipment. I have a mechanically-minded friend, so I see a DIY project in the coming months. I have heard likewise on the PSE rebates, so will hope for the best on that front.

  19. ruffryder | | #19

    S K,

    Where are you located? I live in Fall City. Also, here are some good links to the HTP Phoenix install from the Terrylove plumbing website (no affiliation)

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