------------------------------------- sms9758 i am looking at a heat pump and prices quoted are 7000+ and then another
5000 for the lp gas backup. is this normal? Do I really need the backup gas in northeast ohio or notTell em you only have $500 to spend. anytime they try to quote a larger price, yell "Dot foo! Dot foo!" and they will understand.
Your question is like calling a car dealership and asking "How much is a car?, and do I really need a transmission with that??"
The *real* question you need to ask is... do I want the single most expensive appliance in my home put in cheap? or do I want it done right..... the first time.
Would you mind heating your home with electric space heaters when the temps got near freezing? The cost will be the same (assuming air source).
A more interesting question, I believe, is do you need a heat pump?
There are a ton of caveats, such as using a ground source heat pump.
In NE Ohio, the best he is gonna do for up front and operating costs is an air source, split heat pump with a Mod 90 gas furnace. The Geothermal or ground source is nice, but.... the initial installation cost(providing he has the real estate to do it) is going to be prohibitive. Consider that he is either going to have to dig up an acre of land for the ground loops, or drill a dozen water wells, pump(s), and assocoated piping on top of the expense of the system and installation.
That is what my brother in Cleveland has, but natural gas. You gotta have AC so the heat pump is not a stretch. Easy enough. I remember all those weeks where it was it never got out of the teens or single digits. So no gas seems frightening.
The Geothermal or
Seems that way to me. There aren't that many, are there? But on a new development out in the sticks, it would seem to be a lot more doable.
j
I would really REALLY appreciate it if you would rephrase that one .....
Where is that guy from St Paul that could put in a water source heat pump in a standard back yard for only $14,000? ;-/
People in any trade are protective of their expertise. So, it is that the response is usually to take it to a professional.
For those of us with some skill, this is frustrating.
Someone could have simply said, yes, you can't run a heat pump by itself in sub freezing temps. But what happened instead are dispersions as to the financial ability to just go out and not only hire a professional but trust his advice explicitly.
If you can prove me wrong on any of these points, I would be more than happy to rephrase that.
Myself, I have some questions about orifice sizing, sub cooling and parking freon in the compressor. I don't ask that because I know what the result would be. So although there is no reason for any of you to have sympathy for someone out of the trade, I do. It's just that simple.
I'm not trying to pick a fight, and I will probably regret sending this.
j
Actually, you can. There is nothing special about 32F, unless you're a drop of water, in which case you better pack because you'll be moving ( from one state to another ). The thermal balance point ( the point at which the total heating load equals the output capacity of the HP at that temperature ) depends on a complex calculation that cmobines building performance ( insulation etc ) and HP performance ( size etc ). A line can be charted showing the heat loss of the building increasing as it gets colder outside, and another line showing the output of the HP decreasing as it gets colder, and at some point they cross. That is the thermal balance point. The economic balance point will generally be much lower.
I meant the 'blow you off' thing. It's kinda gay, you know ?
I am not a pro either, just someone who knows enough to do it properly but doesn't have the money or time to get the tools and certifications.
I know someone who has his 609 cert yet doesn't know it as that (he just vaguely recalls having once taken the open book certification test) doesn't have a charging weight scale or a micron gauge, uses standard refrigeration mineral oil in his vacuum pump, has put "freeze 12" in car R-134a systems because "it won't leak out as fast" (never mind that the 20% R-142b will kill the PAG oil) In fact I don't even think he is aware that "freeze 12" is a blend.
It is maddening to me.
Forget the orifice and just install expansion valves (TXV/TEV), to do this properly will require liquid line drier, receiver, and sight glass. Charge until the sight glass is clear, adjust the superheat with the TXV making sure the sight glass stays clear, then once the system has stabilized set the subcooling so that the receiver always has a little excess liquid in it.
If you have problems with compressor flooded starts install a pumpdown liquid line solenoid valve and suction pressure switch along with a start capacitor and potential (5-2-1) relay.
BTW I still think it sounds unprofessional to use the term Freon generically to refer to refrigerants that aren't a Freon at all. Only CFC and HCFC refrigerants can be called Freon, even though it is a DuPont registered trademark, kind of like how locking pliers from any manufacturer are sometimes called Vise-Grip. But calling HFC refrigerants like R-134a Freon instead of Suva is like calling a Crescent wrench a Vise-Grip.
Here in the South, it's called a 'thumb wrench'.
I assume this is in the "you get what you pay for" category and a two stage could push lower. For electric strips and a single stage the figures I've seen are around freezing where it is cheaper to heat alternatively. I would think LPG is cheaper than electrity in most locations. I have no real knowledge of current real world, so I defer to your judgment.
There is nothing special about 32F, unless you're
Where the house can no longer maintain temp.
The economic
I would have thought that would be an entirely different calculation.
Oh, I didn't intend it that way. Comment retracted.
j
ouch.
, has put "freeze 12" in car R-134a systems
ouch ouch
So much for the compressor.
In fact I don't even think he is aware that "freeze 12" is
Is there a temperature glide with that?
That makes sense to me. I had wanted to do that because it makes more sense (to me) to have constant superheat. Do you need a separate receiver than the liquid line drier?
OK. R22 is a kosher Freon then.
My GF's Dad used to work for DuPont in that division. They had stacks of R12 in the garage. It would have been worth real money now!
jes called Vise-Grip. But calling HFC refrigerants like R-134a Freon
j
response is usually to take it to a
sub freezing temps. But what happened
only hire a professional but trust his
to rephrase that.
doesn't have the money or time to get the
vaguely recalls having once taken the open
gauge, uses standard refrigeration mineral
won't leak out as fast" (never mind that
that "freeze 12" is a blend.
freon in the compressor. I don't ask that
any of you to have sympathy for someone
properly will require liquid line drier,
superheat with the TXV making sure the
(*then once the system has stabilized set the subcooling so that the receiver always has a little excess liquid in it.*)
Daniel could you please explain setence above to me how you set subcolind so that reciever always has little excess liquid, sorry but i never hear of such?
line solenoid valve and suction pressure
to refer to refrigerants that aren't a
it is a DuPont registered trademark,
Vise-Grip. But calling HFC refrigerants
Yep.
It is. It is the point where the energy input cost per heat BTU gained by the HP is greater than the cost of the backup method.
IOW, the HP can continue to run economically well below the thermal balance point of the system, although it needs added help from strips, furnace, etc, to maintain temps.
I don't understand this. I would think it would be either the HP or the alternate heat, not both at the same time. Are we talking a seasonal economics or, as I assumed the energy cost in real time?
j
It is not an either / or choice, if the system is properly designed and installed.
Some are installed with the HP coil downstream of the aux heat, in which case you need a lock-out switch to prevent both from running at the same time.
IOW, do not allow the HP to run if the aux heat method is blowing pre-heated air over the coil.
However, if properly designed, the HP coil is upstream from the aux heat source, and can continue to contribute BTU's at a lower cost ( if you are above the economic balance point ) than the aux source ( this of course depends on the BTU cost of the aux source ), even though it needs help to acheive total heat gain required.
I can see that. And I can see now how adding heat to the HP outlet is sorta like topping up.
j
Yep. The HP runs as first stage ( and the ONLY stage, unless it's real cold outside ), and the aux heat comes on as needed to supplement it. Generally speaking, the HP is your cheapest source of heat, as it's only moving heat from outside to inside, instead of creating it via combustion or resistance heat etc.
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