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Old 11-19-2011, 06:11 AM   #1
mikell
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Heat Pumps

Just wondering if everyone with a heat pump is as happy as I am. It keeps the place warm very quietly and even when the temps are in the low 30's. It's managed to keep the place cool once I turned the fan to manual and put it on medium. All in all real suprised and real happy. We have an Alpine 3640rl so it's on the large size. I haven't used the furnace yet other than to test it and to take the chill off one morning when we forgot to turn anuthing on.
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Old 11-19-2011, 06:33 AM   #2
Johnnyfry
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Heat pump

This sounds like a really good deal. The stock furnace is noisy and not the best with regard to even heat distribution.

Did it come installed, or did you add it later? How much did it cost?

John
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Old 11-19-2011, 07:03 AM   #3
mikell
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It came installed but they may replace a roof AC unit if you looked. I think they are about $1000 but haven't looked for an aftermarket one. Just ducted in like the newer AC units. We don't even hear it. The compressor comes on for probably less than a minute before the fan kicks in. I'm really impressed
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Old 11-19-2011, 08:43 AM   #4
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Mikell On the Montana we have on order i'll have to see if the a/c can be swapped out for the heat pump, sure sounds to me the way to go. In your other thread I didn't hear one complaint on the Heat Pump. As well as they work in a home, they definetly would be nice in an RV. Them forced air furnaces sure have alot of fan noise, with my bad hearing every time the dang thing kicks on, the TV has to go up a little louder. We try to use our plug in electric heaters as much as possible but that's a pain makeing sure not to overload a curcuit.

Keep enjoying your Alpine and Happy Campin.................Ron
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Old 11-21-2011, 11:33 AM   #5
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I took a temperature logger home for the weekend and the inside temp never vaired over +- 2F. I would say thats pretty darned good but I kept the fan on low. With the fan on auto during the day it'll drop about 3 but never got over the setting
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Old 11-21-2011, 03:58 PM   #6
hankaye
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Howdy All;

One thing to remember about the heatpumps is that they are limited to being able to heat to within 30 degrees of the outside temp.
If it's 20 degrees outside the inside temp will not get much above (if any), 50.
That's my understanding of heatpumps.....

hankaye
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Old 11-21-2011, 05:20 PM   #7
Bob Landry
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Quote:
Originally Posted by hankaye View Post
Howdy All;

One thing to remember about the heatpumps is that they are limited to being able to heat to within 30 degrees of the outside temp.
If it's 20 degrees outside the inside temp will not get much above (if any), 50.
That's my understanding of heatpumps.....

hankaye
Well, that's not exactly the operating parameter. Heat pumps usualy don't work very well with below around 35-40 degree ambient temperature. They will extract heat from the air flowing over the condenser, which in heat mode is actually the evaporator, and once that ambient temp gets too low to provide enough heat, the unit, for all practical purposes, stops functioning. In the case of the Dometic units, there is a freeze sensor that keeps the compressor from operating. I assume there is a "spilt" in heat mode just as there is the 20 degree split across the coil in cool mode, but I'm nor sure what it is. At any rate, the split is going to relate to the output and return air temps and will be irrelevant to the outside temperature.
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Old 11-22-2011, 04:06 AM   #8
mikell
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Well I can tell you this one puts good warm air when it's 30 or less outside. It keeps it 72 no problem. I'll put the logger in the vent and one outside next week to track the temps
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Old 11-22-2011, 07:28 AM   #9
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Howdy All;

I'd be glad to see the info. from the temp. loggers.

My previous post was referencing all of the phone calls I'd get in the winter from all the folks living in Base housing each winter when the temps. would drop below 30 deg F. and their inside temps were hanging around 60 deg.F.
Stick & brick heatpumps (outside units) will generally require a secondary source for optimal heating during the winter.

hankaye
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Old 11-22-2011, 08:35 AM   #10
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I haven't really had much time to look up all the details on this thing but it does work wonderful.
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Old 11-22-2011, 12:08 PM   #11
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Heat pump

Hank,

It is generally true that a HP has an aux heater. The one in our townhouse is 10kW (which we call the watt sucker). The thermostat turns the HP on when the temp drops by 1 degree in the house. If it keeps dropping it turns the watt suckers on when it hits 3 degrees drop.

It works pretty well without turning the watt suckers on down to about 20 degrees F. IF, and this is a big deal, you keep the temp steady at one setting, say 70 degrees. It will not pull the temp up without engaging the big watts.
Below 20, or if there is a wind, it needs the boost. At that temp the compressor is running 100% of the time.

I suspect that it should pretty much work the same way in the trailer. I think that the aux electric resistance element is an essential considering the insulation in these trailers.

In the end I think that the advantage lies in much more even heat than the propane furnace and I would really like to hear some reports from the field before I pony up the bucks.

John
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Old 11-22-2011, 05:11 PM   #12
mikell
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Well this is the local stuff and it's about a mile away

http://www.crh.noaa.gov/data/obhistory/KBEH.html
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Old 11-22-2011, 08:10 PM   #13
hankaye
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mikell, Howdy;
This is where I spent the past 2 winters.

http://weather.yahoo.com/climo/USUT0...?woeid=2455358

The weather sta. is over the Washach Plateau in Price. These temps. reflect that. Mount Pleasant sits in a valley between 2 mountain ranges and ALL the cold air drops down off the mountains into Sanpete County/valley. We've had -20, -30 & -40 degree days without the windchill.
Took around 60 - 80 gal. of propane a month to keep the temp at 68 -70 deg.
Propane ran for $2.88/gal. so I spent $172.00 to $230.00 last year for 4 months. My elect. bills were close to $120.00 a month (16 cents per KwHr). most of that was dirving the charging side of the inverter so to have power to run the heater blowermotor. That was in my old (1995 TT).

Now Rascal and I are spending the winter here;

http://weather.yahoo.com/climo/USNM0...?woeid=2356207

Much better already ...so far in 2008 Couger.

hankaye
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Old 11-23-2011, 06:43 AM   #14
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Mikell -
I have downloaded the heat pump documents from Dometic's support website. If I remember correctly, the roof mounted heat pump on our Alpines do not have heat strips - or as JohnnyFry says "watt suckers". So if you are getting warm air, it has to be pulled from the outside. Just keep an eye on the unit so it doesn't freeze (as Bob Laundry wrote).

We have not really had a chance yet to try the heat pump. We did try once last spring, but like you mentioned, it doesn't really switch on Auto from cool to heat. I took the easy way out and just turned to Furn. Now I'm real interested to try the heat pump!

Ron
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Old 11-25-2011, 05:28 PM   #15
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Well Tuesday it's supposed to get below freezing a bit ans Sunday it'll only be 43 so I'll start tracking sometime then. Have been gone for turkey day and train rides tomorrow and Sunday so it'll be another busy weekend. We expect about 3000 people for the weekend
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Old 11-27-2011, 05:17 AM   #16
mikell
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46 OUTSIDE AND THE HEAT COMING OUT OF THE VENT IN THE BEDROOM IS 111 So thats 65 degree rise?? Just started logging in the duct. Turned the heat from 68 to 72 to take a shower
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Old 11-27-2011, 05:26 AM   #17
Johnnyfry
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Heat pump

111F sounds about right. Unlike a gas furnace which have a plenum temp of 160 or more, heat pumps usually put out air which is just perceptibly warm at the register. This sounds more and more like something I want to buy.

BTW: 3,000 people --- you REALLY have a big family!

John
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Old 11-27-2011, 09:01 AM   #18
hankaye
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mikell, Howdy;

The 'logger' in the vent will only tell you what it "feels" like at the vent. I don't sit or fit in a vent.
Try placeing it where you sit to watch tv or read a book or tye flys, or whatever it is that you do while inside.
Had a mechanic once tell me the A/C in my truck was working fine as the temp. at the vent was reading what it was (in his opinion), should be( I think it was 45 deg.). I asked him to put his thermometer where my face would normaly be ( that reading was 94 deg.). I asked him how I was supposed to feel it when it wasn't there. He went back to work and an hour later the temp. at "head zone" was 70 deg. Much more conducive to an alert driver as opposed to one that would be sleepy or tired due to the heat.
Same thing for heating... If you can not experience it where YOU are then you are just wasting energy. IMO.

hankaye
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Home: 2008 Cougar 278 RKS
T.V.: 2004 F-250 4X4, Level III BulletProofed , Detroit Tru-Track Differential (915A550)
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Old 11-28-2011, 03:58 AM   #19
mikell
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Pulled it from the vent last night and it was 101 but the thermostat had already been turned to 68 was 36 outside when I did it. Sit on gounter all night and logged between 66 and 68 all night. It got down to 32. Cranked it up to 75 at 5:30 to get ready for work and was kicking out pretty good but not as fast by any means as the furnace. Will log in the chair tonight if I get a chance. Shut the unit off this morning don't really need heat.
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Old 11-28-2011, 07:53 AM   #20
hankaye
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mikell, Howdy;

Thanks for the readings from different locations.

Are you a fulltimer? If so, how much does this "boost" your electric bill.
May be to early to tell yet I know. However, how many kw/hr does it eat in a 24 hour period vs how many kw/hr for just the furnace?
My electric charge is 0.15 cents per kw/hr. What is your's???
Between the propane and the elect. it gets very expensive some months...

Thanks again;

hankaye
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Home: 2008 Cougar 278 RKS
T.V.: 2004 F-250 4X4, Level III BulletProofed , Detroit Tru-Track Differential (915A550)
Dog: 2006 Border Collie (Rascal) aka Maximum fur dispersal unit. (08/04/2006 - 12/16/2017) RIP.
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