Furnace fan speed

MrG · 11-20-2005, 06:57 PM

Anyone figure out how to lower the fan speed on low. It's too loud and fast and doesn't seem any dif than hi. JG

MrG · 11-20-2005, 06:57 PM

Anyone figure out how to lower the fan speed on low. It's too loud and fast and doesn't seem any dif than hi. JG

The Clock Meister · 11-20-2005, 09:13 PM

Yours may be different than my gas coach, on mine there is only one speed for the gas furnace. The speed selection on the thermostat is only for the basement air/heat pump.

I'm sure there is a way to slow down the furnace fan, but it is likely that you would run into problems with the temperature in the plenum that would cause the furnace to shut down when it really shouldn't. I'm sure wiser folks than I may respond to that.

Chris

John_Canfield · 11-21-2005, 02:51 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by The Clock Meister:
Yours may be different than my gas coach, on mine there is only one speed for the gas furnace. The speed selection on the thermostat is only for the basement air/heat pump.

I'm sure there is a way to slow down the furnace fan, but it is likely that you would run into problems with the temperature in the plenum that would cause the furnace to shut down when it really shouldn't. I'm sure wiser folks than I may respond to that.
Chris </div></BLOCKQUOTE>Couldn't have said it better.

troth · 11-21-2005, 03:49 AM

Another thread of info on the fan "whine":
http://irv2.infopop.cc/eve/forums/a/tpc/f/2486094452/m/6761025771/r/9241045771#9241045771

The Shadow · 11-21-2005, 04:57 AM

Last spring I asked about the fan speeds (heat pump) since I was convinced we really on had one speed. Well, high and low were so close that it didn't matter which one was on.

Fan speed

Well, nothing changed with my new unit. High and low can be selected but there is virtually no difference between them.

MrG · 11-21-2005, 06:32 AM

Thank you all for your input and links. I'll also look for return air restrictions.
How well does the heatpump work in mid to low 30's outside?
Any benifit to using both at a CG with electric and cut down on propane usage if temp not too low?

John_Canfield · 11-21-2005, 07:41 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MrG:
How well does the heatpump work in mid to low 30's outside?
Any benifit to using both at a CG with electric and cut down on propane usage if temp not too low? </div></BLOCKQUOTE>The simple answer is that it doesn't work at all below about 40-42 degees! The stick house heat pump would work okay into the mid 30s - I don't know why this is different from heat pump to heat pump.

Here's what we found while getting into some colder weather last month (lows into the high 20s): There is a feature where the propane furnace will operate with a 5 degree temp difference between set and attained; in other words if you set your thermostat (electric heat mode) to maintain 73 degrees and the heat pump can't attain 73 degrees, the propane furnace will automatically start when the room temp reaches 68 degrees. (I thought this was a 3 degree delta, but the manual says 5 degrees)

At 69 or 70 degrees in the coach, I was not a warm and happy camper - yup - a wimp. So we would either turn on the propane furnace before going to bed, or leave the thermostat in electric heat mode and set the litle bed/bath furnace to about 72 degrees or so. That seemed to work well and we didn't have to heat the entire coach with propane.

I think the bed/bath furnace is only the Vectra/Horizon, but I don't know.

The Shadow · 11-21-2005, 08:01 AM

John, I'm rather surprised at your experience. The HP in our Journey worked well down to at least 35 degrees. We have two roof top units now and on the way down to Florida at the end of October we had 35 degree weather in Ohio and they provided adequate heat. We never used the furnace in the Journey and have yet to use it in the HR. When the temp does drop below the HPs abililty to put out decent heat, we switch to two ceramic heaters and they do a good job. Heat pumps are not quiet and we have found the advantage to having two of them is the ability to run the one up front to keep the noise out of the bedroom.

In our first gasser (Triple E Commander) we had heat strips and they were useless. We had to use the furnace when one night when on the Cabot Trail. What a shock. Until then we were thinking the propane tank never emptied. Ha, the gauge on the tank dropped like a stone.

Tom N · 11-21-2005, 08:18 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> The HP in our Journey worked well down to at least 35 degrees. We have two roof top units now and on the way down to Florida at the end of October we had 35 degree weather in Ohio and they provided adequate heat. We never used the furnace in the Journey and have yet to use it in the HR. </div></BLOCKQUOTE>

My heat pump works into the mid 30's but the air coming out of the ceiling vents is not very warm. But, it is warmer than the ambient temp. We hit the mid 30's here at Myrtle Beach a couple nights last week and mostly used the heat pump. Air coming from the ceiling makes the coach drafty but once the set temp is reached the heat pump does not cycle very often. This coach really holds the heat and is sealed very well.

DancinCampers · 11-21-2005, 11:39 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The stick house heat pump would work okay into the mid 30s - I don't know why this is different from heat pump to heat pump. </div></BLOCKQUOTE>

The TrueAir System does not have a defrost circuit, to remove ice on the outdoor coils, as do the home units.

According to the manual, the Heat Pump will shut-down usually when outside air temps are between 25 to 40 deg F. This is controlled by the Heat Freeze thermistor which opens at 18 deg F and closes at 38 deg F., Actual Coil Temperature (+/- 3 deg F).

If the Heat pump did not shut down at lower temps, the outdoor coils would continue to ice over more with each cycle, & soon would be an ice cube. The home units handle this by going through a defrost cycle, which entails going back into Air Conditioning mode while at same time turning on electric heat coils in the indoor unit until the ice is melted off the outdoor coil.

If you see a home heat pump frozen over it is usually because the defrost circuit quit working.

Cruzer · 11-21-2005, 12:32 PM

I'd be very careful about running heat pumps under 40 degrees. On our first RV (you know - the one you learn on and make mistakes with

), which was a 2003 Suncruiser, we had the basement air with heat pumps. We first got our unit the end of October so we did some shakedown trips in the area and it generally got down around 30 degrees at night. We found that the heat pumps acted pretty much the same way that Tom N found they did. They work, but not very well. We had a number of times where they would quit making heat and that was when the coils were all frosted up. Letting them sit and defrost for a while then kicking in again would buy us more time.

Eventually, the unit started making some noises and eventually seized up. It was replaced under warranty. The tech at my Itasca dealer said that there should be a low temp cutoff switch to stop it once it gets below 40 degrees but that he had seen them vary in settings from between 30 and 40 degrees. The reason for the safety cutoff is to prevent seizing of the pump in low temps. He replaced my cutoff switch also.

Heat pumps are a part of the air conditioner system. A/C units need to run in some pretty hot conditions so the compressor is lubricated with a fairly heavy oil that won't break down in hot temps. Unfortunately, that same oil gets thick as mollases in low temps and the compressor pump does not get adequate lubrication and can fail. Seeing as how heat pumps aren't that efficient below 40, they just install a low temp cutout to protect the unit. However, some of these may not kick in until it's too late. After that I never ran mine below 40 (well almost 40 anyway

) and had no more problems.

MrG · 11-22-2005, 05:33 AM

Thanks for your comments and input on your experiences. I guess I'll use HP till about 40 and then use HP/propane combo so as not to screw up the compressor.

The Shadow · 11-22-2005, 03:01 PM

Yes, most helpful comments. I'm going to refrain from using mine below 40 and switch over to the ceramic heaters in such cases.

Thanks.

The Shadow · 01-07-2006, 07:08 PM

Well, we are heading to a cool, make that very cool, 36 degrees or so this evening.

Out came the HR manual. Turns out that our 2 roof top HPs can be operated down to 30 deg F (at which point the furnace will start). In addition the manual points out:

"When ambient temperature is between 30 to 42 deg F, a defrost cycle is initiated approximately every 40 minutes of compressor operation. The blower motor will stop for five minutes and DEFROST will be displayed. After the defrowst cycle the heat pump operation will resume."

It sure was nice to learn that we have the defrost cycle.