Posted By PARAHOMES on 29 Jan 2017 11:06 AM

Now that I took the time to look deeper, your running 2-1 ton outdoor units 1- 12K indoor, 500 SF, both not shown in NEEPs cold climate database. It explains the issues with HSPF in low cold temp performances (tested @ steady state, sub-17F), provides better info than mfgs. These properties are related and one should not be changed w/o changing the other.

http://www.neep.org/initiatives/hig...-heat-pump

That NEEP report is actually readable. Thanks for the link. There are differences from my situation. The study was in NH, climate zone 5. The Mitsubishi units were FE models, so work down to -14F. Mine are GE models, good down to -4F. My cabin situation is different, but my house is similar.

Bottom line is that even if I can't calculate precisely the cost savings, I can be sure there are some savings most of the time. The payback would be very long if I had only or mainly bought these for heating, as did the NH people. But it was just the opposite. My main need is cooling. In summer, we also may have wildfire smoke even when nights are cool. I have to close windows and use a/c to have decent indoor air. So I consider heating to be a plus. My investment for heating is only the delta between an a/c minisplit and one with heating, too.

The climate details of Spokane aren't super relevant. North central WA has many mountain valley micro-climates, and is on the order of ~100 miles or more away from Spokane.

Only a very small slice of NH is in US climate zone 5- most of the NEEP in-situ test sites in NH were in US climate zone 6.

Posted By RandySea on 29 Jan 2017 08:47 PM

Posted By PARAHOMES on 29 Jan 2017 11:06 AM

Now that I took the time to look deeper, your running 2-1 ton outdoor units 1- 12K indoor, 500 SF, both not shown in NEEPs cold climate database. It explains the issues with HSPF in low cold temp performances (tested @ steady state, sub-17F), provides better info than mfgs. These properties are related and one should not be changed w/o changing the other.

http://www.neep.org/initiatives/hig...-heat-pump

That NEEP report is actually readable. Thanks for the link. There are differences from my situation. The study was in NH, climate zone 5. The Mitsubishi units were FE models, so work down to -14F. Mine are GE models, good down to -4F. My cabin situation is different, but my house is similar.

Bottom line is that even if I can't calculate precisely the cost savings, I can be sure there are some savings most of the time. The payback would be very long if I had only or mainly bought these for heating, as did the NH people. But it was just the opposite. My main need is cooling. In summer, we also may have wildfire smoke even when nights are cool. I have to close windows and use a/c to have decent indoor air. So I consider heating to be a plus. My investment for heating is only the delta between an a/c minisplit and one with heating, too.

I'm not sure you followed what I did. It does not matter where the NEEP study was I used Spokane to simulate your homes CC_HPMS using the newer/latest static FH (a little more efficient than yours) mfg data down to -5F BUT the program runs insitu dynamic relationships it takes down to weather tower temps (dry/wet bulb) I can view I posted, to mfg data and accurately puts out hourly COP.

Had you given me a more accurate climate tower locations I could tell you very closely what your pay backs are. If I could not find a weather tower within 50 miles or less you have to buy one for me to use, and I need to go to a more accurate program that considers the elevation & exact orientation of your building with respect to the tower and alot more site info like directional loads, and of course I don't provide that level of detail for free....

There is NO WAY anyone can do this looking at general climate zones and mfg limited data, you can be WAY off as I shown between EPLUS and MJ......Alot of inaccurate advice on this site & others like GBA results when ppl try to interpret limited data they don't understand or don't have to the tools to.

So, you guessed it correctly in the beginning of your thread it's too complex for words blah blah bah and I proved that. 

If your cabin is on a well, you do know the lowest point-- where the pipe down to the pump sits on the house supply nipple inside the casing. Lift it off and the water in the house runs back into the well. This job could be either a mankiller or a breeze depending on how deep the well is. You could a build rigging over the pipe to make it easier. I'd treat it a step in winterizing the cabin and carry in a couple Jerry cans for the commode and some drinking water on rare winter visits.

Parahomes: My understanding is admittedly limited. My main point was that the study as I read it used Mitsubishis with a lower temp range, and the test points for temps were not total consistent with mine. Neither of those points changes my bottom line or yours - it is too complex for an accurate prediction based on limited info but overall I should have some cost savings. I think we agree on that.

Todd M: My well is down a hill, 75" deep, and 400" from the cabin. In between is my main house and an underground pressure tank. There is a backflow valve between the pressure tank and the main pipe going down the hill. There is unfortunately not even a separate shutoff between the pressure tank and the cabin. Getting to The lowest point near the cabin would be a job for a jackhammer through a concrete slab.

RandySea, I rewrote your statement more accurately...

it is too complex for ANY NON_PRO WITHOUT THE PROPER SIMULATION TOOLS & KNOWLEDGE TO OBTAIN accurate prediction based on limited MFG & GENERAL WEATHER ZONE info but overall I should have some cost savings IF THE HPMS are ran. I think we agree on that. YES!

Interesting part is Manual J shows your 12k won't work you need 24 a person trying to add another output with less info can be even further off. EPLUS shows less than 12K should work so the CC-HPMS newer FH model I used should perform just fine in Spokane anyway. The NEEPS table is mfg data down to -5F/17F I used and your model is not far less in COP values. They are snap shots in time easily misunderstood when compared to zonal weather that is not accurate either. Actual COP is determine seasonally or better annually, over even longer if needed like if SITE directional load climate(not weather) varies annually these CFD models can simulate very accurately before you buy or build. These cold climate models are getting better and it's more than COP at -5/17F.

Interesting how Chiltrix new CX34 is claiming they have higher COP running R410A to water lines by modulating pressures/flows, latent heat, and have built in back-up by a cheap small tank in their auto ran system that can't be done with HPMS I been looking at, but cost is ~$3,000 higher. Read the white paper for more info, out soon. I think it's clear based on we seen here BU baseboards can drastically ruin CC_HPMS COP. Where it gets complex is how often will the BU be needed. That s/b low to none.

So your answer is if you look at the hourly power/BTU graphs is there is no outside temp your baseboards will have a higher COP down to -5F.

I wish this model outputed a COP comparison. I plan on suggesting that on their forums. It recently add CC-MSHP using up-to-date NEEPs data for any cold climate zone 4+, multiple zoning, input parameters now there are alot of ways to define performance it gets complex getting the right inputs in and knowing how to read the many outputs including cost. With 20% - 50%+ difference between manual J & simulation outputs more difficult to determine capacities, without all the inputs/outputs to view some ppl can be way off or got lucky guessing or still are consuming high power utility bills for all they know are not optimized. Same with all sim softwares needing pros that run HVAC sims you don't get off  forums. Problem is difficult to find MSHP moreso CC-MSHP local pros, so, DIYs come here or GBA trying to save initial pro cost end up paying many times fold over time for not.

"Getting to The lowest point near the cabin would be a job for a jackhammer through a concrete slab. "

TODDM may be on his way with explosives, Spokane base camp, seems too determined to drain your lines. Take cover! 10-4 good idea not disclosing your local' :)

Posted By PARAHOMES on 04 Feb 2017 08:23 AM
RandySea, I rewrote your statement more accurately...

it is too complex for ANY NON_PRO WITHOUT THE PROPER SIMULATION TOOLS & KNOWLEDGE TO OBTAIN accurate prediction based on limited MFG & GENERAL WEATHER ZONE info but overall I should have some cost savings IF THE HPMS are ran. I think we agree on that. YES!

. . .

. . .  I think it's clear based on we seen here BU baseboards can drastically ruin CC_HPMS COP. Where it gets complex is how often will the BU be needed. That s/b low to none.

So your answer is if you look at the hourly power/BTU graphs is there is no outside temp your baseboards will have a higher COP down to -5F.

Yes, that first paragraph is EXACTLY what I meant. Thanks for the clarification.

I don't understand the next two sentences I quoted.

The last sentence I quoted is the final answer. 

There is something I should add from recent experience in my main house. This is fyi. Really, I am not asking you for any calculations, especialy because it "is what it is." I have a dual unit, but rarely use the upstairs head (guest room). The downstairs great room (living, dining, kitchen) has a 12k head. The room is roughly 25x26, partly with an 11' fake cathedral (i.e., scissor truss) ceiling. Roughly 33 linear feat of varying sized windows, all U 0.34. (Yes, I'd need the window area for a real calculation, but we're not doing that.) Walls are 8" thick, insulation there, ceiling, and floor, well above Code.

The house was designed for wood (or eventually propane) as a primary winter heat source for the great room. Nonetheless, there is enough baseboard heat for when the wood stove is not in use. If we had sustained nights of -10 or lower, and days below zero, I am guessing that we might not be able to stay above 68.

When the temp gets down below +5 outside, the minisplit alone is not enough. To me, that doesn't mean we should have gotten a larger unit. We bought the unit for cooling, and that is how it was sized. I can say that with temps outside at over 100 and lots of sun, we have no trouble cooling the great room and well down the hallway. The heat pump feature was something we added because the price difference wasn't that much.

Our electricity right now costs $0.045 (not a typo)  Our wood is still under $150/cord. We may have used 1 1/3 cords over the winters before we put in the minisplit. I have to admit that I am a bit more likely, especially in the mornings when the night fire has died out, to turn on the minisplit rather than immediately start the wood. I wouldn't do that with the baseboards because they are so slow to heat. I may also leave the minisplit on during the day if we are in and out a lot and not feeding the fire.

I should add that we cover approx ½ of the electricity for our main house with grid-connected solar. That means our effective electrical cost for the house is under $.025/kWh on an annualized basis. The cabin is on a separate meter with no solar.

A backflow preventer in your house is pointless. Your well has a foot valve at the bottom water from the pump to the highest point in your house. My well is 600 feet deep. No backflow preventer needed. What you describe makes your task super simple. Remove the backflow preventer. Go downhill until the line drains to daylight, figuring in the depth it is buried. Plumb a yard hydrant into the line. https://jet.com/product/detail/f37520842b8c4171955ecaf3e0723a78?jcmp=pla:ggl:a_nj_dur_gen_hardware_a1_b1:plumbing_plumbing_fixture_hardware_parts_a1_other:naLA_648327839_30263588182_pla-161714563020:na:na:na:2&code=PLA15

Parahomes: Since we are taliking green building here, which is the most environmentally friendly: minisplits, baseboards, or no energy expended at all on heat that isn't necessary.

Todd, I actually do have a hydrant halfway down the hill to my pump. In a different setup. I imagine it could work However here there are two problems. The big one is that I would have to drain my main house and the shared pressure tank each time I wanted to drain the cabin. Then I would close the main line into the cabin and refill the house water lines, bleeding air, etc. And that assumes it would actually drain all the pipes in the not-very-plumb old cabin, which my plumber doubts would happen without blowing them out.

The second problem is the ice ponds that would be created every time I opened the hydrant and drained the water from the houses. Incidentally, this is related to why I retrofitted a back flow valve several years ago, when we just had the cabin. But that is another story not related to "green building".

PARA: I think it's clear based on we seen here BU baseboards can drastically ruin CC_HPMS COP. Where it gets complex is how often will the BU be needed. That s/b low to none.

RS: I don't understand the next two sentences I quoted.

I'm just saying the minute we need back-up like BB or space heaters as part of the CC_HPMS system the total COP goes down. I have the option to size CC-HPMS with different BUs. This is what Chiltrix C45 is hanging their hat on, although the rep I been debating with is not aware of the latest CC_HPMS tech.

I see with the unit I used in Spokane the cooling capacities are much higher June-Sept than heating but, if you used manual J8, not S, or got confused about the rated cooling capacity vs required heating capacities at low temps, so if you don't size the heating based on the inputs I posted you can come up empty handed. If you go back & look at the kWh input power per hour I posted you will see it is inline with NEEPs @-5F. This is one way I know my model is accurate and the inputs are correct. Your power inputs s/b very close to .15 - 1.80 modulating too.

TODDM: Parahomes: Since we are talking green building here, which is the most environmentally friendly: minisplits, baseboards, or no energy expended at all on heat that isn't necessary.

I dunno could just be me, RS seems to be smarter than the average HO I wish my clients were, my guess went over the plumbing options w/plumber too before asking CC_HPMS vs BB no plumbing questions in OP.

Lets not play the green card when it's convenient. This small leaky poorly insulated cabin in Spokane is using ~ < 5 metric tons/yr CO2, most 3-5xs that. Probably a fraction IIRC your ICF foam production and all the mfg production exceeds by far.

Do you even know how much Co2 your home is producing?

BTW: When we talk utility CO2 that includes the mfg plants & embodied energy. There is nothing "green" about any of the green sites or advisors selling products that are not green anymore that was ruined along time ago making it a misnomer. They can't make $$$ on better natural products you can find in your back yard so they don't want you to know.

RS: Our electricity right now costs $0.045 (not a typo)

I don't get this the state ave is $.08..with rates that low run anything you want.

Here is one I'm working on Z4, it has 4 zoned ductless CC-HPMS one HP up, three down plus 4 more registers driven by handler ducts, ducted ERV tied or may go ductless....I don't recommend combustibles in air tight or any home. You don't have to look far to see the IAQ issues they cause, so I am recommending electric PV tied fire place. It's not always about utility bills, health problems can wipe those saving out easily.

Great Rm 40x40..still moving things around....10' lower, 8" upper, 8 3/8" walls, vaulted scissors 15' peaks, loss 10KBTU/hr there.

Parahomes, thanks again for your concern. My xps was salvaged from industrial demolition. Cost $10/2" sheet. ICF was the least expensive choice for a complicated 36 inch frost wall. I switched then to AAC, which as you might know cuts cement use by 80 percent. I heat with deadfall hardwood I cut myself. Carbon neutral. It's giving it up regardless, rot or combustion.

Randysea: Two houses on one pressure tank is a not a great situation, although it sounds like cabin use is discretionary. Even then, one problem can have twice the consequences.

Posted By toddm on 05 Feb 2017 10:24 PM
Parahomes, thanks again for your concern. My xps was salvaged from industrial demolition. Cost $10/2" sheet. ICF was the least expensive choice for a complicated 36 inch frost wall. I switched then to AAC, which  percent. I heat with deadfall hardwood I cut myself. Carbon neutral. It's giving it up regardless, rot or combustion.

Randysea: Two houses on one pressure tank is a not a great situation, although it sounds like cabin use is discretionary. Even then, one problem can have twice the consequences.

Well good you found some foam to recycle and keep it from ending up in landfills, not bio degrading, ending up in our oceans. I seen some NASTY TOXIC pictures of that killing ocean life dead fish everywhere and silly people think it does not produce mold when it sees moisture. Still, foam production is not "GREEN" to support it is not "GREEN" the next persons may not recycle it and most do not. Low consumer cost does not equal "GREEN". A GREEN product would be BIO DEGRADABLE FOAM.

Whether burning wood is "carbon neutral" is highly debatable. What I was referring to mainly is CO poisoning in the home, especially air tight, where it can be harder to exhaust and, no air is not always the answer, it mainly depends on atomic weights/charge (+/-) and what it attaches to. Look what it is doing to RandySeas environment OAQ/IAQ health, an air tight HRV home would not be a good idea around wild fire smoke, so as a result smoke is causing more CO2 home emissions. Last I researched this Rumford is the cleanest burn highest COP or a rocket mass heater exhaust smokeless but, in any case there is no way to avoid CO infiltration to IAQ @ start-up. If you add the cost of potential health problems, cost of buying or ones labor chopping wood when they could be relaxing, I don't see this as a good BU. If you want aesthetics of fire electric PV tied is the "GREENEST" option and they are looking real these days, or, Chiltrix controls a BU water tank to the HP handlers.

"as you might know cuts cement use by 80%"

Yes I know, and I'd like to see a structural AAC that dropped OPC (Organic Portland Cement) that high, 2-3%, or even non it would not hold together I would not trust that over time. Please post the mechanical properties and MFG? In addition to toxic foam production, ICF is not a GREEN choice since it uses large quantities of CHEAP OPC limestone burnt in a kiln @ 2500-3000 F producing lots of CO2 ICF HOs supported. What needs to happen is we need to get rid of, stop supporting OPC production. There are better natural cements like MAGNESIUM, LIME, that are burnt about 1000F less needing 2/3 less cement to get the same compression allowable and, it is not as thermally conductive so the thickness goes down. They react better with recycled fly ash, and other pozzolans and there are local mining co's like Premier.  There are other more GREEN concrete choices that use no OPC and don't have the issues of OPC most don't "know" about. 

I guess you missed the word "deadfall" Parahomes. Fuel is literally falling from the sky where I live thanks to the emerald borer and the locust borer. Deadfall isn't really the right word. I'm working on dead trees that are upright so far. Then there's the leaners, and finally deadfall. While we might argue that living trees are more valuable than firewood, what I am doing is in fact carbon neutral and responsible woodlot management.

Finding reclaimed foam board isn't difficult at all. It winds up in landfills because new has greater mark-up potential. My focus on the other kind of green-- money -- isn't unusual at all in homebuilding. Thing is, from the builder's side of the table the goal is more rather than less, even at the expense of the environment.

I guess you missed the word "deadfall" Parahomes. Fuel is literally falling from the sky where I live thanks to the emerald borer and the locust borer. Deadfall isn't really the right word. I'm working on dead trees that are upright so far. Then there's the leaners, and finally deadfall. While we might argue that living trees are more valuable than firewood, what I am doing is in fact carbon neutral and responsible woodlot management.

Finding reclaimed foam board isn't difficult at all. It winds up in landfills because new has greater mark-up potential. My focus on the other kind of green-- money -- isn't unusual at all in homebuilding. Thing is, from the builder's side of the table the goal is more rather than less, even at the expense of the environment.

Point is when it comes to IAQ there are better back up heat choices than fire & smoke toxic gas combustibles especially in Passive homes and, when it comes to "GREEN' there are better choices than synthetic chem treated ICF foam (recycled or not) /OPC concrete, especially if the the foam vapor locks the OPC which most designs do. Been an interesting discussion, thanks!

Thank you, Para and Todd. This has been quite a learning experience for me.

I do have two small comments of no great import. First, I agree with Todd about two houses on one pressure tank not being ideal. Still, lots of people around here do it simply to save costs.
I have actually had 4 houses running on that one pressure tank. Two years ago in the giant Carlton Complex fire, the power was out for eight days. I was the only one around with a full time, hardwired
propane generator. My sprinklers were running full time. I also ran hoses to two neighbors' homes. They used hose couplers to connect to their outside water faucets, thus bringing water into their houses.

Originally, the plan was to take down the cabin shortly after finishing the house, or let the termites do it. But the exterminator did too good a job. And the cabin has been too useful for storage and
occasional guest overflow.

Para, on the CO and wildfire problem, our only alternative is to evacuate when the smoke gets too bad. Been there, hated it. Also, I used to have a Seattle house to go to. That's sold. So we do the best we can.
We close windows, though there are still the Code required vents. We run the a/c and, for the particulates, a high quality HEPA filtration air purifier. Last summer we had no fires and no super hot days. Best summer
in anyone's memory. Unfortunately, that will be the exception, and get rarer and rarer over time.

Posted By RandySea on 06 Feb 2017 02:58 PM

I have actually had 4 houses running on that one pressure tank.

Randy, You might want to look into changing your "tank" over to a Cycle Stop Valve setup. It's inexpensive to change over and it is w-a-y better than a pressure tank - especially for multiple uses on the same tank. The people down there are extremely helpful so if you get stuck on what setup is best for you, just ask them! You will not have a pressure drop again, and your pump will last a lot longer too. http://www.cyclestopvalves.com/

Thanks, Roger. We did talk to our well and pump guy when we built the new house and had to move the pressure tank anyway. He recommended a constant pressure system, too.
But he said given our heavy freezes, they only install these systems indoors. They make too much noise too close to our bedroom for where we could put it.

Multiple house use is rare, so it really isn't a problem.

Randy, Just for future reference, if you get to a point of having to replace your pressure tank or pump, the Cycle Stop Valve setup is only as noisy as your pump and w-a-y cheaper than a constant pressure pump system.
The manufacture says they last a lot longer than a constant pressure pump too.
Ours is in a pump house with a weatherized plywood & insulated foam box around it (with a light bulb).