should i get the a/c with the heat pump??

[Inland RV Center, In]

Originally Posted by evelitalian

my a/c is shot,i was looking into the a/c heat pump combo,one unit dual purpose,what do you think?any suggestions,anyone have this?

Heat pumps wear out much faster, than a regular AC.

When a heat pump is in operation, either in the AC mode or heat mode, the compressor always runs. You basically reverse the two coils, internally.

With a regular AC, the compressor only runs when it's in the "cool" mode.

And as some have pointed out, the heat pump model, when in the "heat" mode, is noisy.

Purchasing a new AC with a heat strip option, costs very little extra, and is not noisy in the heat mode.

Andy

[vswingfield]

Hi Andy,

Valid point about the life of the unit. It certainly is bound to shorten the life somewhat. However, here in Little Rock or in Georgia where evelitalian is located, it won’t shorten the life very much since it will be cooling most of the time anyway. I did take the effect on the effective life of the unit into consideration.

[vswingfield]

Well, Arkansas weather came through for a heat pump evaluation. Last weekend we had 75 degrees and a tornado. Night before last, it got down to 34.5 with freeze warnings for last night, but it didn’t make it below the previous nights low. Anyway, the heat pump performed very well. My primary heat is an oil radiator with the AC as supplemental heat. The heat pump switched over to the heat strip when the temperature dropped, and when it got back to 40 switched back. This morning I noticed that the heat pump was running and blowing warm air at 36, so I am not quite sure where the switching takes place. It did keep the place very comfortable, though. I’m glad I got it.

[TBRich]

Might as well chime in here with my 2 cents...we have a heat pump and find it great for day time warming when it's not too awfully cold out...it's noisy at night but so is the AC (and sometimes in AZ you need the AC even at night)...so we are used to sleeping through it...whether it's the heat pump or the AC on... I'd rather use the heat pump and use the electricity we're paying for in a park rather than our propane, though the furnace is more efficient and quieter. I'm glad we have both.

[jcanavera]

Lot's of folks have talked about the "noise" from a heat pump, but in reality the noise is typically the noise of the fan and the air flow. Technically the additional noise that a heat pump generates is the sound of the compressor running and is the same noise that occurs when you are in the cooling mode.

That sound in my trailer is a low hum and is really inconsequential to the noise that the fan and air flow produces. When you have a heat strip you still have the sound of the fan and air flow. From my perspective the difference in inside sound levels between a heat pump running and a heat strip running are really minor. The convenience of the heat pump/AC side being thermostatically controlled is really a plus. Keep in mind that at least with the Duo-Therm thermostat, you can set the heat pump/AC unit to automatic mode which completely shuts down the fan and compressor when cooling or heating isn't being called for, much like the furnace. Again that's something you can only do manually with a heat strip.

Personally I think the furnace and its whine is a lot more annoying that the heat pump.

Jack

[vswingfield]

Jack made a good point about the noise coming from the blower. My Carrier AirV seems to only have 2 speeds, Extra High and Scream like a Banshee. My older Excella doesn’t have an external thermostat like Jack’s, so the difference in the heat pump and heat strip is moot. It’s on all the time.

Here in Little Rock, the AC gets used a lot too, so I am getting used to the sound pretty quickly.

[jcanavera]

Originally Posted by vswingfield

Jack made a good point about the noise coming from the blower. My Carrier AirV seems to only have 2 speeds, Extra High and Scream like a Banshee. .

The difference in speeds for most air conditioner fans is really minor since there is a minimal amount of air flow needed to make the system work properly. The Duo-Therm thermostat used on the heat pump units has an excellent option of setting the unit on auto, and cycling the fan and compressor off once you hit set point. It however, has another side which I think is awful. When set to auto, the thermostat determines which fan speed to use. The problem is the decision point as to what fan speed to use. That decision is determined by the difference in the actual trailer temp, and the set point of the thermostat.

For example when doing the initial startup in a hot trailer, my cool set point is 77 degrees. The unit starts up on high producing maximum cooling. Once the inside air temp cools down to 87, the fan automatically kicks down to a lower speed. Bad side is 87 is still obviously too warm. So I have to either kick the thermostat down to a lower temp, to keep the fan up high, or I turn the fan mode from auto to high. Not too bad you say.

Ok here's a much more common scene. I like to use auto since in a cooling mode, it keeps humidity levels fairly low (using constant fan on blows air over the coils when the compressor isn't running thus introducing more humidity into the air). Problem is when you are in full sun hot climes in auto mode (and the trailer is cool to begin with, say early am,), the fan and compressor will cycle in low speed mode. Now the morning heats up and the fan/compressor run time gets longer to get the trailer back to set point. Eventually you reach a point where the fan speed is insufficient to provide enough air flow to provide proper cooling and the temperature starts to climb in the trailer above the set point. Unfortunately the high speed won't activate until the thermostat shows a 10 degree difference, and my trailer now is at 88 degrees before the additional blower speed is activated.

This I think is a bad design and probably in retrospect the auto function should default to high speed once you pass 4 degrees over/under set point. Right now the way we have to deal with it takes some of the auto out of "auto". The same issue happens in heat pump mode where you want fast recovery when entering a cold trailer, or as outside temps start going down. Running constant fan when the compressor is cycling, makes for some cold drafts. A proper auto fan speed selection would make it a lot more comfortable.

Jack

[pmclemore]

Our Safari had just a heat strip and it wasn't worth the effort to turn it on. Our Limited has the heat pump and it works well - much better.

But what works best, when you have AC, of course, is our Vornado. That little thing heats our 31 footer very well - and the temp is pretty constant, top to bottom. And quiet. When it reaches the set temp, it just idles down to near nothing. Great to sleep with.

I've never found anything that works as well.

Pat

[overlander63]

Originally Posted by vswingfield

Jack made a good point about the noise coming from the blower. My Carrier AirV seems to only have 2 speeds, Extra High and Scream like a Banshee. My older Excella doesn’t have an external thermostat like Jack’s, so the difference in the heat pump and heat strip is moot. It’s on all the time.

Here in Little Rock, the AC gets used a lot too, so I am getting used to the sound pretty quickly.

Vaughan, I think you can get the lower unit with the remote t-stat, it's really nice to have the thermostat turn the works off when temp is reached.

[53flyingcloud]

Originally Posted by evelitalian

my a/c is shot,i was looking into the a/c heat pump combo,one unit dual purpose,what do you think?any suggestions,anyone have this?

I have the Carrier A/C with the heat pump on my unit..If I am not mistaken, that's available only in the 15K BTU..You might find it a bit too cold..lol
My unit is a 29ft Sovereign and, it really get cold in there with the 15K unit.
Other than that,
I'd say go for it..It's a extremely nice A/C unit..

[vswingfield]

Originally Posted by overlander63

Vaughan, I think you can get the lower unit with the remote t-stat, it's really nice to have the thermostat turn the works off when temp is reached.

Hi Terry,

The thermostat controlled lower unit is for ducted systems. The “Freeblow” bottom that I have just has the knob on the bottom. I have considered a hack and adding a digital thermostat as has been discussed in other threads, but it’s just one more thing. Besides, even in its “Scream like a Banshee” setting it is still quieter than the old Coleman. Not much, but still quieter. Now when the Coleman started knocking in addition to the fan, it was really loud!

[floridalarry]

Yep. I'm going with the 15,000 btu v the 13,500. The dealer suggested that if I plan to use electric, I first need to be hocked up and if I'm hooked up, I might as well get a small ceramic heater. Save $300 and the it's quite.

[vswingfield]

Originally Posted by floridalarry

Yep. I'm going with the 15,000 btu v the 13,500. The dealer suggested that if I plan to use electric, I first need to be hocked up and if I'm hooked up, I might as well get a small ceramic heater. Save $300 and the it's quite.

I had always used the ceramic heaters till this year. When my ceramic heater quit working, I bought one of those oil radiators with a digital control. It heats my trailer so much better than the ceramic ones did! It is still my primary source of heat, the heat pump/strip backs it up. It’s not quick, but once it warms up the warm air rolls up at an unbelievable speed. With no fan, it is totally quiet. I use one of those small clip-on fans to circulate air, and they are almost soundless.

[floridalarry]

I'm in the same boat (or trailer). I decided to go with an A/C only rather than an air/heat combo The difference is around $300. I decided to upgrade from the 13,500 btu to the 15,000 btu for $100 more. The dealer said that they have more problems with the combos and if we are at a CG and on electric, why not by a small ceramic heater for around $40 . . . uses the free electric and is much more quite than the heat pump running.

[floridalarry]

Great idea. I never thought about that. Thanks.

[Jaxon]

Originally Posted by vswingfield

I had always used the ceramic heaters till this year. When my ceramic heater quit working, I bought one of those oil radiators with a digital control. It heats my trailer so much better than the ceramic ones did! It is still my primary source of heat, the heat pump/strip backs it up. It’s not quick, but once it warms up the warm air rolls up at an unbelievable speed. With no fan, it is totally quiet. I use one of those small clip-on fans to circulate air, and they are almost soundless.

Vaughan, You've posted about the oil radiator before and raved. We've used the ceramics, too and are OK with 'em... just OK... what you describe sounds pretty hot, man... what brand/model are you using?
Bill

[vswingfield]

Originally Posted by Jaxon

Vaughan, You've posted about the oil radiator before and raved. We've used the ceramics, too and are OK with 'em... just OK... what you describe sounds pretty hot, man... what brand/model are you using?
Bill

Hi Bill,

I have a Honeywell Model HZ-709 that I got from Wally World. The digital model is more expensive, but you can set a temperature accurately and leave it on, no more setting it to low and coming back to 95 inside. I usually set mine to 67.

I was not prepared for the difference in performance. This winter was the most comfortable I have spent in an Airstream. I attribute it (1) to the improvements to Airstreams from 1967 to 1983 {double-pane windows, for instance} and (2) to how much better the oil radiator works. I doubt if you would have to turn on the furnace more than a couple of times all winter in Austin. That’s all I used mine here in Little Rock. As far as I am concerned, that little thing is the best thing since balanced running gear.

[Jaxon]

Originally Posted by vswingfield

Hi Bill, As far as I am concerned, that little thing is the best thing since balanced running gear.

And mylar drum heads...

Thanks Vaughan!