Elect Heater Question

mrsr71 · 10-05-2007, 06:36 AM

What is the lowest outside temp that the heat-pump will work?

Dan - Low on propane in the snow, in the Eastern Sierra's.

mrsr71 · 10-05-2007, 06:36 AM

What is the lowest outside temp that the heat-pump will work?

Dan - Low on propane in the snow, in the Eastern Sierra's.

robbstein · 10-05-2007, 07:24 AM

Dan..
My experience with the heat pump says about 40 degrees is the lower limit. I've had it work a couple of degrees below that, but if there is much humidity the cooling coils will freeze up. (you'll see frost on them through the grill).

Robb & Sue Steinheider
Duncan the Dalmation
03 Ultimate Advantage
02 Saturn L100 Toad

Harry B · 10-05-2007, 07:25 AM

Dan,

I have had my heat pump work yet at around 38-40 degrees but is not very efficient anymore.

nanathorn · 10-05-2007, 08:45 AM

We were in Indianapolis when we first bought our Meridian. The temperature dropped to 28 one night and I noticed the heat pump after trying to do it's thing automatically switched to the propane heater. Unfortunately, the propane froze up and our heater would not work. We took it back three days in a row to the dealer and they checked everything thing they could possibly think of but never told us that the propane could freeze up.

Later, in Texas, one night in December, we experienced the same situation. The temperature dropped to 28 and the heat pump stopped and the propane heater attempted to come on and failed. We called our propane dealer and he is the one that told us that the moisture can freeze in the propane. We needed to add something into the propane when he filled us up next that would prevent it. So far we haven't been in a situation to need it.

I noticed that Winnebago sells a propane tank cover. I wonder if this helps at all.

DancinCampers · 10-05-2007, 08:50 AM

The temp at which the heat pump will continue to operate is controlled by the outdoor coil freeze sensor. The sensor will open at 18deg F and close at 38deg F, (coil temp, not air temp). The tolerance is +/- 3deg F.

Once you get the coils cold enough and the unit shuts off because the freeze sensor opens, then the coil temp needs to raise enough to close the sensor (35 to 41 deg F). If your freeze sensor happens to be one which closes at the lower end (35 deg F), then the unit will operate at lower temps than one which closes at the higher end (41 deg F). The amount of frost on the coil, which relates to humidity, also factors into how long it would take for the coil to reach the sensor setpoint.

If these heatpumps were equipped with defrost capabilities like home units are, they would operate well below 30 deg F.

Now, throw the thermostat into the mix and things can get screwy. In the electric heat mode, you have 2 stage heat. The first is the heat pump (both compressors), the second is the LP furnace. If the heat pump can't maintain the set point temp, the LP kicks in. If this happens 3 times in a row, without a 20 minute period of the heatpump not requiring LP backup, then the thermostat will lock-out the heatpump for 2 hrs, during which time the LP will operate alone as called for by the tstat. After 2 hrs, the system will reset. Now the heatpump will come on, but this time it gets only 1 strike. If it can't maintain set-point temp and LP come on, it is locked out for another 2 hrs. And so on, until the heatpump can satisfy the setpoint, then cycle starts over.

If you are in a 2 hr lockout you may think the heatpump went bad, but not so. I believe, although the documents don't say, that you can reset this lockout manually by turning the termostat off, then on. I think this resets the internal strike counter.

skigramp · 10-05-2007, 08:56 AM

I live in Wisconsin ... I have never heard of propane freezing ... our propane must have additives mixed in before it is delivered to us ...

My LP furnace works down into the teens ... I know ... been there done that ... before we leave for southern destinations after the holidays ...

Savannah · 10-05-2007, 10:00 AM

Never heard of propane freezing. We've used our propane is below zero temps with no problems. Maybe a call to Winnebago Service can be of some help.

Rocky Larson · 10-05-2007, 10:55 AM

The further south you go the more chance your "Propane" supply will have some "Butane" mixed in. It's not about freezing, it just that butane doesn't vaporize at the same lower temperatures that you are used to with propane.
You'll have a tank full of liquid that you can't burn, until it warms up. It usually happens if you are traveling north to the colder areas after filling up south in the warmer areas. Try to buy your propane where you are going to use it, not carry it long distances. BTW, North to South is OK, South to North is the problem.

rvcarpenter · 10-05-2007, 10:57 AM

Never ever heard of propane freezing., routinely use it in the winter to go skiing at temps of 10 to 15 deg F, been in -15 deg F with no problem.

rvcarpenter · 10-05-2007, 10:58 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rocky Larson:
The further south you go the more chance your "Propane" supply will have some "Butane" mixed in. It's not about freezing, it just that butane doesn't vaporize at the same lower temperatures that you are used to with propane.
You'll have a tank full of liquid that you can't burn, until it warms up. It usually happens if you are traveling north to the colder areas after filling up south in the warmer areas. Try to buy your propane where you are going to use it, not carry it long distances. BTW, North to South is OK, South to North is the problem. </div></BLOCKQUOTE>

ahh now that makes more sense

TXiceman · 10-05-2007, 11:00 AM

Propane will not freeze at anything near normal temperatures. It's pressure will go to 0 PSIG around -40 dF, it will not boil off vapor for the appliances.

Now if you have any water in the propane, it will not mix with the propane and it will freeze and may wind up in the regulator. The dealer can put some alcohol in the tank and it will help.

Ken

DonavonP · 10-10-2007, 12:58 PM

New propane tanks should be purged before use. My guess is that very few RV propane tanks are purged. I have also read about many RV propane regulators being replaced as defective when in reality I believe they are simply freezing.

I had this problem and was shopping for a new regulator when the propane guy at Waconia Farm Supply told me to try his alcohol fix first. That solved the problem.

Regulators can freeze with an ambient temperature well into the 50's F. even 60's if your consuming gas fast.

If you suspect this problem, go to a propane distribution plant like a farm supply etc. Not a gasoline station with a stand alone propane tank. Have them inject a pint or two of Isopropyl alcohol (not methanol- hard on seals). When your burning off the treated tank, you may see a slightly different color flame but I doubt it. I didn't.

If your tank is empty, you can make your own injector and use a 20 lb cylinder to push the alcohol in but it's really not worth the 30+ dollars in parts.

FrontRangeRVer · 10-10-2007, 01:32 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by nanathorn:
We were in Indianapolis when we first bought our Meridian. The temperature dropped to 28 one night and I noticed the heat pump after trying to do it's thing automatically switched to the propane heater. Unfortunately, the propane froze up and our heater would not work. We took it back three days in a row to the dealer and they checked everything thing they could possibly think of but never told us that the propane could freeze up.

Later, in Texas, one night in December, we experienced the same situation. The temperature dropped to 28 and the heat pump stopped and the propane heater attempted to come on and failed. We called our propane dealer and he is the one that told us that the moisture can freeze in the propane. We needed to add something into the propane when he filled us up next that would prevent it. So far we haven't been in a situation to need it.

I noticed that Winnebago sells a propane tank cover. I wonder if this helps at all. </div></BLOCKQUOTE>

You got a bad batch of propane....we use our propane in 0 degrees F all the time....