Since l'm stuck in sunny victoria l decided to run my reverse cycle air con during the night. Temp was supposed to be 1 degree overnight.
All was good inside den 15 degrees C. Outside temp hit 4 degrees when the unit suddenly shut down. What the!! Unit was dead. Got out the destruction manual and after reading pages of useless info, last page held the answer. The unit will turn off automatically at 4 degrees C and turn back on at 9 degrees C. Who knew?
Since l'm stuck in sunny victoria l decided to run my reverse cycle air con during the night. Temp was supposed to be 1 degree overnight. All was good inside den 15 degrees C. Outside temp hit 4 degrees when the unit suddenly shut down. What the!! Unit was dead. Got out the destruction manual and after reading pages of useless info, last page held the answer. The unit will turn off automatically at 4 degrees C and turn back on at 9 degrees C. Who knew?
Not good....what brand is your AC? I too have a reverse cycle system.Looks like I might have to do some more research! Luckily, I also have a diesel heater,but the AC works off batteries and Solar,so cheaper to run.Cheers
My den is 9 years old now and has a Dometic B3200 rooftop heatpump. I believe the compressor produces the heat.
I made a mistake the ambient thermostat shuts the unit down at 4 degrees C. It will prevent operation until the temp is above 7 degrees C. In my opinion pretty useless when the brass monkey's needs it the most! My solution today visit store and brought a portable heater.
Cupie l wish l was elsewhere for sure.
Reverse cycle air conditioners work by taking heat from one side and dumping it into the other side of the unit. In order for them to work, they use a fan to pull air over a set of coils. As the fan draws air through the coils, the air velocity is increased. This has 2 effects - (1) it makes noise, and (2) it lowers the pressure as the air passes over the coils. In doing so, the temperature also drops and if the drop in temperature is enough, ice will form and then block off airflow through the coils. This is why the units shut down when the temperature reaches a certain level. Split system domestic A/C units generally go to a much lower temperature than a window package unit because they have a much larger area over which they can mount the coils. Thus, they only typically have 2 rows of coils whereas a window package unit (or a caravan unit) may have 3 or 4 rows of coils. By the time the air reaches the 3rd or 4th coils, the temperature has probably dropped well below freezing as well. When the unit freezes up, typically the TX valve is switched to bleed warm refrigerant gas back through the frozen coils to thaw then out and if you are lucky, the unit may then re-start once tie ice has gone.
Humidity of the outside air also plays a part. If the air is dry, the unit can operate much longer before it freezes up. Split system domestic A/C units can operate down to -10 Deg C, although obviously with lower overall efficiency than with a more normal temperature. There is nothing you can do about this effect, so you need an alternative form of heater, and a small electric fan heater does the trick very well.
We have installed a diesel heater and inthe cold cold winter we turn it on prior to getting out of bed. Also carry a small electric blower heater when we are on power.
Hardly use the rooftop van airconditioner as it sound like a jumbo jet. Maybe because it is a 2008 model that came with the van.
I was wondering if the latest roof top A/C. are very nosy.???.
Might drop into a C.Van sales yard and get a demo.
Jay&Dee
Reverse cycle air conditioners work by taking heat from one side and dumping it into the other side of the unit. In order for them to work, they use a fan to pull air over a set of coils. As the fan draws air through the coils, the air velocity is increased. This has 2 effects - (1) it makes noise, and (2) it lowers the pressure as the air passes over the coils. In doing so, the temperature also drops and if the drop in temperature is enough, ice will form and then block off airflow through the coils. This is why the units shut down when the temperature reaches a certain level. Split system domestic A/C units generally go to a much lower temperature than a window package unit because they have a much larger area over which they can mount the coils. Thus, they only typically have 2 rows of coils whereas a window package unit (or a caravan unit) may have 3 or 4 rows of coils. By the time the air reaches the 3rd or 4th coils, the temperature has probably dropped well below freezing as well. When the unit freezes up, typically the TX valve is switched to bleed warm refrigerant gas back through the frozen coils to thaw then out and if you are lucky, the unit may then re-start once tie ice has gone.
Humidity of the outside air also plays a part. If the air is dry, the unit can operate much longer before it freezes up. Split system domestic A/C units can operate down to -10 Deg C, although obviously with lower overall efficiency than with a more normal temperature. There is nothing you can do about this effect, so you need an alternative form of heater, and a small electric fan heater does the trick very well.
Thanks for that useful explanation of how the AC unit works.
Explains why my unit refuses to cool. The shroud over the roof top unit has warped badly over time preventing the fan from turning freely. Before I replace the rarely used AC system I will try it without the shroud in place.
-- Edited by Cupie on Friday 31st of May 2019 01:43:50 PM
The newer inverter split system unit at home goes into a defrost mode where it turns the vents inside to face toward the ceiling and uses a bit of the heat from inside to melt the ice on the outside unit if it freezes up before it can stop it occurring by recirculating the heat it has already extracted from the outside air. Hoping it doesn't get cold enough this yr for it to stop operating all together, it is the only heating we have at home.
T1 Terry
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I have a 15 year old Kelvinator window aircond that I put in the wall a home when new, it works down to 3 deg, but it didn't like having to do that about 4 years ago, and blew the capacitor. I go a pair of cap. to replace the dual single unit from some older airconds, fitted them , and it has worked ever since. But when it gets colder I shut it down and use the wood stove/heater, which also heaters the whole home. I now use a Gasmate heater in the van with suitable venting, and it costs just $1.19 to run for 4.5 hours a night.
