Heat Pump question...

[955Lincoln]

Glad that you got your unit working Moss.

I'm not a HVAC person but I know my older system inside and out because I have had to repair it so many times. 30yo Carrier but the outdoor unit was replaced maybe 10 years ago.

Newer smart systems and thermostats may have a work around for this problem but I wired my system with an outdoor thermostat to keep the EM heat from coming on when you turn up the heat more than a few degrees. The problem is, when the unit goes into defrost (which switches to A/C mode with outdoor fan not running) you get the blast of cold air inside because it won't allow the EM heat to come on while in defrost unless the outdoor thermo is tripped due to cold weather. If I had 2 outdoor thermostats, the second one (set colder) could switch the system over to backup heat when it's really cold outside and the heat pump isn't efficient anymore.

 

[955Lincoln]

I bought one of the newer ones at lowes and it should have been compatible with my single stage heat pump but would not run right. I even took it back for a new one. I got on the phone with honeywell or whoever made it they went over my settings and could not figure it. You need that "heat recovery setting" This will gradually step the heat up for when a new temp program comes up so that there should not be a 2 degreee difference to keep the strips from coming on. Mine works with out strips on all but the very coldest days (i have no insulation inmy walls.). That new one i got would act like it worked but i would come home at 4:30 when it was supposed to be 65 in the house with the heat recovery setting so no strips should be used. Anyway it would be 72F in the house with heat stips running? Why it did this i have no idea, it was only when it warmed the house up any other time that program would maintain 65F but the first time it turned the heat on for the program its like it hung up? My point in saying this is that just cause you buy o program t stat it may not be compatible even though it says it is?

You must have the same model Honeywell that I have and if I was smart I would take a sledge hammer to it. Same problem, when it's cold outside and I turn the heat up from a setback it will climb 3 or 4 degrees higher than I want. When it's not so cold outside and the pump can warm the house during a reasonable time frame it works ok. I really can't use the program features because of this problem, which is why I bought it, so I use it like a manual thermostat and inch it up a little at a time. I spent a lot of time on the phone with Honeywell and the frustration level was off the scale getting a different person each time and having to describe the problem over and over with no results.

 

[LD1]

For the most control over your heating, you need a manual t-stat. Not a programmable one.

My wife and I both work days. It is as simple as turning it down before we go to bed, then turning it down some more when we go to work. Then turning it up when we get home.

 

[clemsonfor]

You must have the same model Honeywell that I have and if I was smart I would take a sledge hammer to it. Same problem, when it's cold outside and I turn the heat up from a setback it will climb 3 or 4 degrees higher than I want. When it's not so cold outside and the pump can warm the house during a reasonable time frame it works ok. I really can't use the program features because of this problem, which is why I bought it, so I use it like a manual thermostat and inch it up a little at a time. I spent a lot of time on the phone with Honeywell and the frustration level was off the scale getting a different person each time and having to describe the problem over and over with no results.

It could be hunter? It was the MId or top grade one they had at lowes. Aboiut a 2x3 inch touch screen. I think it was back lit in blue and or orange depending on heat or cool mode. I took it back and got my $60 or so back from lowes. I told them that it flat out did not work and i had 2 installed at the house. And that it was not my incompitance as i have a probly 10 year old one on the wall thats worked perfectly for months in all settings. I just wanteed something more "modern" looking and not the old giant t-stat i have. A few years later i still have the one i got of ebay for a deal working!

 

[LD1]

In my saturday morning boredom, I comprised a spread sheet similar to the one I use that you all can check out.

All you have to do is input the info in the RED boxes and it should give you outputs.

If you dont have propane or natural gas, you can leave those sections blank.

If you dont have an amp meter to check your HP, you can use the FLA data on the nameplate outdoors. Just be sure to add them together. Because with mine, they list the compressor FLA, and the Outdoor Fan FLA seperatally. You dont need to worry about the blower inside for this. Because it is constant no matter what of the 4 forms of heating we are comparing on that spreadsheet.

I left my inputs in there in the red boxes so you can see what I am looking for. Feel free to try it out and share your results. As you can see with my #'s left in there, propane isnt much better than straight electric resistive heat:confused2: Not sure on Nat gas, but I always heard it was ~$1 per 100cf. If that is true, you guys are lucky

Hopefully the attachment works, since we cannot upload .xls format directly

 

[Mickey_Fx]

GRS,

What T-Stat do you recomend? My unit is like a 2007 unit, Carrier.

I would like more control over its performance.

Thanks in advance,

David

Been away from this thread for a few days so I'd chime in again.

David, check with you dealer to see what is available that works with your current equipment. In prior post you said the few features I mentioned are way more than yours. I have a Bryant a sister company to Carrier. Same thing with different name. Dealer said some of their equipment comes with labels for them to attach, either Bryant or Carrier.

In one of my posts I spoke about defrost cycles and how that can impact power usage with electric aux heat. Just to back up what I said, decided to take a look see at the recorded data. First stage is lowest and third the highest and is what is on during defrost cycle.

With lock-out point set @ 30F here are the run times in hrs for each heat cycle. 1st = 16, 2nd = 6, 3rd = 36 of which 31 hrs for just defrost. So far this yr HP cycles are as follows. Heat = 1894, Defrost 972. That's a whole lot of cycling and time spent on defrosting. Based on this I've adj the lock-out temp up to 35F in attempt to drop the number of defrost cycles. Could be even with the higher temp setting, total time and amount of aux heat could be less. So having the lock-out set to very low temps may not be the low cost solutions. Lot depends upon humidity during the winter months.

 

[techman]

I have a similar sheet that I have used for a number of years. It compares all of the common fuels.

paul

 

[LD1]

I have a similar sheet that I have used for a number of years. It compares all of the common fuels.

paul

I like it:thumbsup:

Allthough, A HP is constantally variable. You list the COP @ 2.2. That is probabally about what mine runs @ 35-40 degrees. But it is more around 3.5 when temps are near 50, and less than 2.2 when colder. That is the Idea behind my spreadsheet is to be able to calculate it at different temps in comparison.

And there are a few other "specific" questions I would like to ask you if ya dont mind?

First, you list the price ranges for NAT gas as 1.50-2.25/ccf. I personally dont know, we dont have gas in our area, but I had always heard it was between 0.90 and 1.10/ccf. I have no good sources for verifying, most people I know that have NG, have no clue:confused2: Could you shed some light?

Second, I think most propane furnaces are 90% or better eff. I could be wrong. Why did you go with 80%?

Third, I have always been told that burning wood is only 20-30% efficent. The rest goes up the chimney:confused2: That could skew them #'s a bit for the worse. Where did you get The 70% # at???

Not trying to discredit any of your info, just curious is all

 

[LD1]

Actually I just found this really cool link. It basically has everything your PDF does, only prices and efficiencies are editable:thumbsup: I wish I stumbled onto it sooner.

If it works...

http://www.eia.doe.gov/neic/experts/heatcalc.xls

 

[techman]

I like it:thumbsup:

Allthough, A HP is constantally variable. You list the COP @ 2.2. That is probabally about what mine runs @ 35-40 degrees. But it is more around 3.5 when temps are near 50, and less than 2.2 when colder. That is the Idea behind my spreadsheet is to be able to calculate it at different temps in comparison.

And there are a few other "specific" questions I would like to ask you if ya dont mind?

First, you list the price ranges for NAT gas as 1.50-2.25/ccf. I personally dont know, we dont have gas in our area, but I had always heard it was between 0.90 and 1.10/ccf. I have no good sources for verifying, most people I know that have NG, have no clue:confused2: Could you shed some light?

Second, I think most propane furnaces are 90% or better eff. I could be wrong. Why did you go with 80%?

Third, I have always been told that burning wood is only 20-30% efficent. The rest goes up the chimney:confused2: That could skew them #'s a bit for the worse. Where did you get The 70% # at???

Not trying to discredit any of your info, just curious is all

Well the chart is actually an excel, which allows you to change all of the parameters. Heat pumps are one unit that can vary, so trying to pick an average is a guess. Also we have some guys that have the new, efficient wood stoves, which clain 70% Some of the range of costs are a year or two old, and will vary regionally. Also I try to use fully burdened costs, like on the NG, which includes all taxes, fees, etc. I made this originally to give to some co-workers to try to compare different fuels. In some cases some "low cost" fuels are actually not that much cheaper.

paul