I am posting for a friend that has 2 -9000 btu splits ? is how often are they supposed to recycle or purge I guess you could call it.
They are in Idaho City and freezing their @$# off it got down to 10 degrees last night and is in the 20's now and the heat pumps are not doing the job they are recycling more and more as the temp drops.
He is a little upset told me he was better off with the heat strips in roof airs any of the mini split people have a answer for him will a low or high Freon charge cause that ?
http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/36683/Finding-Balance-Heat-Pump-Heating-Load-vs-Capacity (http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/36683/Finding-Balance-Heat-Pump-Heating-Load-vs-Capacity)
I wouldnt expect a heat pump to work well at those temps in an rv. Too much heat loss with a low output temp from the heat coils, probably 55 to 60 degrees at that temp after some degrees of loss from ducts or housings. He would be better off with a few electric heaters in those situations. Jmo
The cheaper mini splits will not have a an effective heat absorption cycle below 30ish.
The good brands will get you heat down lower , for example the Fuijtsu's will go down to -5F, but I consider anything below 20-10F a need for supplementary heat.
What brand? What humidity level? Exchangers frozen over?
Quote from: Darkspeed on November 21, 2015, 06:08:18 AM
The cheaper mini splits will not have a an effective heat absorption cycle below 30ish.
The good brands will get you heat down lower , for example the Fuijtsu's will go down to -5F, but I consider anything below 20-10F a need for supplementary heat.
What brand? What humidity level? Exchangers frozen over?
Fuijtsus, humidity around 15% and they are new,he solved the problem he didn't remove the rv furance but did the mounted tank so it cost him 100 bucks for propane tanks and fuel, they are warm now she told me and are headed south Monday ;D
Quote from: chessie4905 on November 21, 2015, 06:02:38 AM... I wouldnt expect a heat pump to work well at those temps in an rv. ...
I was in Norway back in the summer and noticed that many homes and businesses had mini-splits. Those units usually had a special name plate on them -- like "Fujitsu/Arctic" or "Panasonic/Polar". I had never seen any nameplates like this on N American heat pumps. I'm guessing they're talking about $$$-sucking (or Kroner sucking) electric strips but obviously they've seen a need and fixed it.
If they were Fuijtsu's and the were installed with the correct ventilation around them they must be undercharged or defective in some way.
If they dont have enough ventilation = no heat at low temps.
Hi, folks.
Those Fujitsus have a BTU rating, and if they use R410A, then they ought to go down into single digits. However, if the BTU rating totals 18000, they will only provide about 2 1/2 portable electric heaters worth at that temperature. As they found out, that isn't enough heat.
The builder made a good choice in leaving the propane furnace in place. I'll bet that they were glad to warm up.
People buy these units for their high efficiency thinking that they are getting more heat, but they are buying less electricity. For cold weather, they need more heat.
One other thing is that sometimes the output air can circle around and come inside as input air. If that happens, you get frequent defrost cycles, which the friend is complaining about.
At outside temperature of 32F, those Fujitsus should have no trouble keeping up, IMO.
For what it's worth.
Tom Caffrey
We can't fool Mother Nature or beat the Laws of Thermodynamics no matter how we try
have the Invert-er type mini split in bus and home. They work fine down in single digits . first installed in 2012. We live in SW Indiana and temp run from slightly below zero to occasional 100 plus. was careful to not recycle condenser air. Bob
I spoke with him a few minutes ago it's 24 degrees in Idaho City they work ok down to around 30 degrees @ 24 degrees they are blowing 52 degrees air and cycling the old rv propane is blowing 105 degrees he is headed south today.He too thinks 18,000 btu is not enough,he said don't expect any help from Fijistu their customer service is worthless
I have three roof airs all with heat strips that will get the interior like a sauna. Also 40,000btu propane furnace. Along with the engine run original heater, could be in a blizzard and be fine. Like having three roof air conditioners, you can't have enough heat. We sometimes just fire up the stove top burners to take the chill out. Good Luck, TomC
You run the heat strip in roof tops on low fan they do a good job it is equal to cube heaters in BTU's but they will use some power and are useless on hi fan BTDT I am keeping my @$# in AZ in the winter ;D
I like my hot water heat, either on diesel or electric always nice and cozy
No sperience with heat pumps, but the Aqua Hot 600 series does the toasty thing. Not cheap but sure is comfy. I set thermostat ar 72 and smile. With bthe LP gas & electric base board heat, that worked too, not as comfy but sure did work.
DaveM
Quote from: wg4t50 on November 23, 2015, 03:50:02 AM
No sperience with heat pumps, but the Aqua Hot 600 series does the toasty thing. Not cheap but sure is comfy. I set thermostat ar 72 and smile. With bthe LP gas & electric base board heat, that worked too, not as comfy but sure did work.
DaveM
Aqua Hots are nice Dave but most people don't want to spend 10 grand + on a heating system in a $10,000 bus ;D
My rooftop heat pump ceases to work about 32 degrees. It makes a whole lot of noise, but little or no heat. A mini split would probably do better.
Heat pumps aren't used much for residential where I live because you have to have a secondary source of heat as the heat pump won't work for much of the winter.
The newer roof tops use 410 also they work a little better than the older models
Great point Clifford(//), what would a pair of the good heat pumps cost ? All correctly installed including basement heat ducting ?
Agree he upgrade AH installed at factory, lil over $15K.
Dave M
Quote from: wg4t50 on November 23, 2015, 07:11:48 AM
Great point Clifford(//), what would a pair of the good heat pumps cost ? All correctly installed including basement heat ducting ?
Agree he upgrade AH installed at factory, lil over $15K.
Dave M e
It would be under 2 grand even at Camping World but the basement heat with a roof top I don't know about that one.FWIW we have a friend that just installed a propane fired Aqua Hot he loves it cost him almost 9 grand
My rooftop heat pump is a fairly new Atwood and I suspect it uses R410. I didn't buy it for the heat pump portion so I have no issues that it won't work below 32F. I just tried it once for the heck of it and it didn't work.
Quote from: luvrbus on November 23, 2015, 07:53:10 AM... we have a friend that just installed a propane fired Aqua Hot he loves it cost him almost 9 grand ...
That's pretty much what I was quoted in NC a couple of years ago (would have been a diesel fired system, but close enough).
Hey Clifford. Your bus was built to go down to -40, without anything freezing. There are heat pads under the tanks, and everything. We successfully took it down to -10. So go
North ;D
;D I know that John 316 I see heaters on everything it amazes me the insulation through out that bus.Since I got you on line Steve said he had a set of manuals for sale ship those to me with a bill and I'll send you a check and feed you all the Sushi you can eat the next time you are in Phoenix
safe travels my friend