Heat Pumps

[mikell]

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.

[Johnnyfry]

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

[mikell]

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

[Ron]

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

[mikell]

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

[hankaye]

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

[Bob Landry]

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.

[mikell]

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

[hankaye]

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

[mikell]

I haven't really had much time to look up all the details on this thing but it does work wonderful.

[Johnnyfry]

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

[mikell]

Well this is the local stuff and it's about a mile away

http://www.crh.noaa.gov/data/obhistory/KBEH.html

[hankaye]

mikell, Howdy;
This is where I spent the past 2 winters.

http://weather.yahoo.com/climo/USUT0175_f.html?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/USNM0018_f.html?woeid=2356207

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

hankaye

[geo]

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

[mikell]

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

[mikell]

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

[Johnnyfry]

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

[hankaye]

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

[mikell]

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.

[hankaye]

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

[mikell]

Were fulltiming and are owners unless you concider the $1500 a month minimum for electric and $600 for water we don't pay for anything just the propane we use and this year someone left behind a full 300# tank so I think were good till about Feburary.I have an inline watt meter but it's for 30 amp cord if somebody wants it make me an offer

The weather has been real wet and cool high 30's and I think the unit freezes up but it knows it and seems to run to thaw it. I might be wrong but that seems to be happening. Snow this afternoon so we'll see what happens in the next week it might be furnace time

[mikell]

Going to call it quits with the logging the unit is working fine but I think all the wet weather is causing it to freeze up but it seems to take care of itself and have only had the furnace on once.

I think it's a wonderul thing to have and works well down to 30 if it's dry then it seems to freeze but does thaw itself out. All in all worth the few extra bucks

[mikell]

Been 30 or less every night and it's still working fine. I'ts slow so in the morning so I turn the furnace on when I hit the shower. it's set at 68 at night and keeps that.

[mikell]

Heatpump update. everything seems to be working fine in the warm Michigan winter. The heat pump has been great and when it defrost the thermostat tells you whats going on. It flashes DEFR . Last night the furnace came on I got up and checked and it was set to heat pump so I can only guess if it's too cold for the heat pump the furnace automatically takes over. Got down to 26 last night. So far it seems to be a great setup.

[CarKath]

Hi Mike;

Can you post what thermostat and what settings you are using? I am not getting the same results as you when heating with the heat pump.

For example, I had thermostat set to heatpump last night. Set point of 69. When I got up this morning it was down to 58 in the trailer. Outside temp was around 39. Also my furnace never kicked in automatically to maintain set point.

So I guess I am asking what mode you use for it to work as it does for yourself?

I would love to use heat pump instead of furnance, but it is not quit keeping up.

Thanks in advance for your input Mike

[mikell]

Don't know I'm just sitting it on HP and it has been working great. It's a 2010 model Alpine so I would assume the HP is about the same year. I was suprised when the furnace kicked in I didn't know it would do that I thought Janet changed the setting. Then this morning it was about 30 and the HP started working again

[CarKath]

Hi Mike;

Here is an image of thermostat I have https://encrypted-tbn1.google.com/images?q=tbn:ANd9GcToChvFldXRo2WFRYRjDFEbf53gAb1_t O0j0Y7D8x79r3ARYIK38w

I did the unthinkable and read over the instructions again. I have done a factory reset on it and will let you know how it works out. I have it set to heat pump at 68 degrees. Fan speed set to auto. It is only supposed to get down to 45 tonight. :thumbsup:

[mikell]

I screwed it up and did a reset and after that was the first time the furnace came on . It is the same thermostat. 33 outside 72 in here

[mikell]

Down t 23 last night the heat pump then let the furnace run. The thermostat flashed HP FURN and kept us warm with 50 MPH winds and all

http://www.crh.noaa.gov/data/obhistory/KBEH.html

[smiller]

Whenever I compute it the cost of propane and resistive electric heat come out to be roughly equivalent (of course much depends on what you pay for each, but assuming national averages it is pretty close.) Since a heat pump is a good deal more efficient than resistive heating I would expect it to be the most economical of all (assuming it is not always below freezing outside.) I'd like to have one and will pay the extra $200-$300 premium for one when my A/C dies, but I don't think it would be cost-effective to toss an existing healthy A/C unit to install a heat pump version. Maybe someday...

[mikell]

You could put the old AC unit in the bedroom area or sell it .You would probably be suprised what it might bring in. The after market wiring might be a bit to deal with though

[LeeMedic]

In very cold environments, doesn't running the furnace help keep the pipes in the basement from freezing up?

[Festus2]

You might want to read geo's recent post in the Repairs and Maintenance section in which he relates his findings about the so-called Polar, Arctic and other names Keystone has given to their units. A great and informative read -- He speaks about insulation and freezing temps with respect to tanks and plumbing.

[geo]

Festus2 -

Thanks! I hope to finish installing the insulation this weekend and will be upgrading my "basement air circulation" contraption in the process. I will also have more comments about tank insulation thanks to Steve's insight and advice! "bouncey: And thanks to Steve's insight, I now have different concerns about these "packages" and how they might add to the moisture content (free water) held inside the basements. When I complete the insulation installation over the top of the tanks, I'll take the final pictures and post this Modification on the forward black and gray1 tanks.

LeeMedic - If you look in the Modifications for 2010, maybe around August or September (?), you will find information on my present "basement air circulation" contraption. It is a 12VDC system that utilizes an Inboard/Outboard Bilge Fan, a 200mm silent computer fan, and plastic/aluminum ductwork. I have decided to replace this with a 120VAC Radon Abatement Fan. When I do, I'll post the results in Modifications.

LeeMedic - Here is the link to the older basement circulator system I built: http://www.keystonerv.org/forums/showthread.php?t=2001

There are several reasons, but I chose not to "winterize" this year. Rather I used my AirWedge/kayak inflator to blow the water out of the lines and am relying on the furnace set at 45F and the circulator to keep the pipes and my Reverse Osmosis unit from freezing. So far, it's been a mild winter in north Texas, so I don't really believe my "system" has been fully tested. Glad it hasn't! :bdance:

Ron

[mikell]

OK 40 today now 29 and still pumping heat. Probably switch to furnace oon but working well

http://www.crh.noaa.gov/data/obhistory/KBEH.html

Going to let this thread die now I do product testing for a living and have a tendency to monitor everything new. So here's a nice litt bunch of data loggers that are really simple to use and quite cheap. Good to diagnose electrical or temperature problems.

http://www.dataq.com/products/hardware/easylog-data-logger.html





Temperature -35 to +80°C
(-31 to +176°F)
Temperature -20 to +60°C
(-4 to +140°F)
Temperature -40 to +125°C
(-40 to +257°F)

Humidity
temperature, dew point 0 to 100% RH
-35 to +80°C
(-31 to +176°F) * * *
*
Voltage 0 to 30 VDC

Process current 4 to 20 mA

Event, State, Count 3-28 VDC

Thermocouple
(no display) -130 to +900°C (J)
-200 to +1300°C (K)
-200 to +350°C (T)

Thermocouple
(with display) -100 to +900°C (J)
-200 to +1300°C (K)
-200 to +400°C (T)

Carbon monoxide 0 to 1000 ppm

PC connected Temperature, Humidity, Dew point