heat pump thermostat question

[ONJ]

I bought a house that has a newly installed Trane air heat pump and an electric furnace emergency backup.

As far as I'm concerned I don't want the HVAC company that installed it to look at it as they want to charge me for an incompetent setup.

The way its set up is the heat pump runs whenever the stat is calling for heat...even down below temps in the teens and colder when the heat pump is obviously useless...it still runs along with the electric furnace. This is a horrible waste of electricity and I figure is costing me about 30% more on my electric bill when the outside temp is that cold.

Anyone know of a thermostat that I can install that is inexpensive as possible that will lock the heat pump out when the electric furnace kicks on? Or one that I can install an outside sensor and the heat pump kicks off at a certain temp and tells the backup to run?

Thanks

[Noon-Air]

You got 3 choices... you can call the installer to come out and correct any problems, or you can call a competent, licensed HVAC tech to come out and correct any problems, or you can live with it.

FWIW, the heat pump and strip heat are doing what they were designed to do, and thats to maintain a constant, even temperature in your home. If you don't like it, have it ripped out and go back with propane or oil heat and let the oil companies bend you over.

[ONJ]

Or I can get a proper thermostat and outdoor sensor and do it myself. Its not that hard, just didn't know which thermostat to use or what is available.

dont HVAC techs just hate it when normal people can do what they can do? Must really suck.

[Bubba]

Clueless sum-biatch, aint cha. As Noon said, read the performance charts you clueless ass-wipe. Bubba

[Simon Schnizzard]

Actually I doubt Noon has ever had to actually understand and apply heat pump heating performance charts.

[jamesgangnc]

The heat pump will be cheaper heat that the resistance heat just about all the time. Natural gas heat becomes cheaper sooner. Get a natural gas backup if you really want to save when it gets real cold. And they will set it up so it completely cuts over based on an outside temp.

[ONJ]

Not only that, it doesn't take a rocket scientist to figure out that heat pump performance charts don't mean a thing if the heat pump is no longer able to bring the indoor temperature up to satisfy the thermostat.

So if a heat pump is running and instead of the indoor temp going up...it goes down...its a waste of electricity for it to run from that point on. Its called common sense which a few of the so-called HVAC techs seem to lack.

Mind you, I'm not talking about the credible techs with real knowledge...just a few hacks that have no business being in the business...like p.jm, Bubba and Noon-Air

[ONJ]

I understand what you are saying...but the problem isn't what is cheaper to use to heat...the problem is the heat pump still running when it no longer can bring the home to the desired temperature because when it runs below a certain outdoor temp the indoor temp decreases when it runs.

I'll just need to pony up the money for an outdoor sensor and a stat that will lock out the heat pump when it no longer can provide heat that contributes to a rising indoor air temp.

[modervador]

Please explain the logic that says that a heat source must exceed the heat loss for it not to be "a waste of electricity." Please corroborate your logic by answering the following questions:

At about 17 degrees Fahrenheit, what is the watts input and BTU/hr output of the system with 1) heat-pump only 2) electric furnace only

3) both ? Now, calculate the EER by dividing BTU/hr output by watts input for each of those three scenarios. Which one gives you the highest EER? If you don't have actual measurements of your system, feel free to consult those performance charts.

[Bubba]

So using your logic (hehehe)............. Id stack two boxes of rocks side by side and still say, "You are dumber than two boxes of rocks". How sad it must be to be that fuquering dumb. Bubba

[jamesgangnc]

You can do that if you want but what they are trying to tell you is that the heat that the heat pump is still contributing to the whole mix is still cheaper btus than the resistance heat, pretty far down the outdoor temp scale. In other words you take the heat pump out of the equation and you will have to make up the portion of the heat that it was generating with resistive heat.

Resistance heat is usually the most expensive btus there is unless you're getting a real deal on electricity.

Yes, it would be fairly simple to add an outdoor thermostat to turn off the outside unit below a set temp. If you don't understand it all well enough to figure out how to do it then you probably should get a pro to do it.

[TH]

[Noon-Air]

Actually I *DO* understand and use performance charts routinely, TYVM. I use them every time I design a system for one of my customers, as I did again this afternoon.

The temperature doesn't have to go *up* for a heat pump to be working....even if its putting out enough heat to partially offset the total heat loss of the structure, its still working. The strips are just there to

*AUGMENT* the heat pump when its not keeping up. Heat pumps at 17F will normally make better than 50% of their total rated heat capacity at 47F. If the heat pump is not correctly installed and the refrigerant charge properly balanced, all bets are off.

Not even close.

What lacks common sense is to make all your wild claims without posting your location, the actual results of the Manual J heat load/loss calculations, the actual air balance results, and make/model/serial numbers of the heat pump, and air handler. Without this minimum information, *NOBODY* can give you any difinitive answers.

Say what you will... but until you actually come and see any of us and witness what we do and how we do it, then you have no basis for your claims.

*Most* of us have been certified master techs for 10 years or more. Thats not something that they give away like they do computer science and liberal arts degrees.

[Noon-Air]

probably an EE

[modervador]

[Simon Schnizzard]

Hey s*****ad appears you sure can read between the lines and stretch things when it suits your agenda.

All of the above including Noon have a high level of technical expertise, just that Noon happens to live in an area where heat pumps rarely if ever even go into defrost mode.

[Zyp]

If you can do it, then do it. Why do you need to ask?

[cnc'sam]

No why is he asking here just he should f****ng do it.

Charge to show up for an hour here my guy is ~$60

Yap yap ya I can hear it now what kinda tech would work for so cheap but save your chompers.

yep he's the subject of 2 lawsuits and several complaints to the BBB.

But he's paid his f****ng dues and beings as he got t-boned by a sheriff's deputy and sitting pretty happy working by himself instead of running 5 techs and 7 trucks then he can pick and choose.

[Stormin Mormon]

Well, if you don't know which thermostat to use.... maybe that knowledge is part of the reason why HVAC guys get training, and experience?

Why should guys go through apprenticeship and seminars, and then tell you for free what they paid to learn?

[Zyp]

Well;

Think about this 'ONJ'.

The facts are, that each 1kw [thousand watts] contain 3,413 btu / h heat. It will take 10kw to produce 34,130 btu / h of heat. Lets look at the power that 10kw uses. @240volt = 42 amps. So for your 34,130 btu / h - you will be using 42 amp hours. Lets look at your 5 ton heat pump. At the outdoor temperature of say 30º F - most heat pumps will produce *about* 75% of their rated capacity [i.e. 44,475 btu / h] and the compressor will draw *about*

75% of its rated running load, [all approximates without knowing the brand and spec.] - which equates to about 34 amps. So lets re-cap - 34,130 btu/h for 42 amp hours of cost [vs] 44,474 btu/ h for 34 amp hours of cost. Hmmm...... if both are in operation, your delivery of heat would be 78,604 btu / h. If you cut off the heat pump, your gonna be shy when you need it the most.

Why don't you just leave it alone, change your air filter often, and keep the outdoor unit coil clean. Call an HVAC pro who's rated for Heat Pump maintenance, be sure the charge is up, pay his bill, and pay the utility bill smiling. All the while keeping you family warm.