tennsmith
Well-known member
This is my first RV with the luxury of basement-type heatpump and air conditioning system. I'm baffled by what I see "mechanically" on my coach and have some questions for you guys who have "been there, done that." First of all, a description of what I see.
My DP (identified below) has a rear-facing radiator and it has two heat exchangers on the sides at the rear. One of them (right side/passenger side) when viewed from the outside appears to be a heat exchanger with no visible fans and when viewed from below, all I can see is a galvanized sheet metal box with a rectangular hole in it and some hardware cloth over the hole to keep varmints out. When the A/C is on, air is being pulled through this condenser from outside the coach and exhausted out the rectangular hole in the bottom and I can feel heat in the air flow. Can't see what is in the box, but the ductwork comes out the rear of the box and goes up into the ceiling at the rear so I assume the evaporator coil and one or more compressors (more about that later) are in this box. The cold air return is under the bed w/filter in the same area and also enters this box.
On the left side, I see a similar sized heat exchanger from the outside, but this one has 2 electric fans attached to it (on the outside between the heat exchanger and the coach grillwork) that either blow air through or draw air through the exchanger. These fans resemble the fans available as aftermarket equipment for auto radiators. Pancake design, not very deep, several blades and a plastic blade guard. No box on this side, from underneath I can see the rear of the heat exchanger and attached to the bottom of it is a long cylindrical tube about 1 1/2" in dia, maybe 2" with some sort of "slide" mechanism that could be a "reversing valve" to change from heat pump to A/C. Nothing else on this side, no sign of a compressor.
The thermostat is one I am sure is made for this type system having an A/C mode, a gas heat mode, and a heat (heatpump) mode. Cool, not cold, air comes from my ceiling vents when the unit is in the A/C mode. I'm not sure if it is working "good" or not. I'm wondering if both compressors are running or if it needs additional refrigerant. As I read thru the forum, they appear to be "marginal" at best. Now the questions:
(1) My EMS panel where it indicates what loads have been shed in reduced power situations, I see A/C compressor #2 listed as one of the things that is powered down, depending on available supply and demand. Where is this #2 compressor and does it run all the time if not shut down by the EMS? Why 2 in the first place? How does one know if both are running? My EMS panel shows a green light beside all the "sheddable loads" when plugged into 50A service and I assume that that means this 2nd compressor is "enabled."
(2) I've never seen any action out of the left side heat exchanger/fans. The fans have never been on. Tried it again today. Should they be on all the time? Do they come on as "reserve" as a function of outside air temperature? Should they be running when the fan on the other side is running? Are they linked with operation of the #2 compressor? Does this side work only in the "heat" mode? I didn't try that. Is this thing even a part of the A/C system or is it a transmission cooler?
(3) Is the cylindrical thingy at the bottom of the left side heat exchanger a reversing valve or something else?
(4) Is there anything that needs service or maintenance inside the box on the right side and, if so, how in the heck does one gain access to it?
(5) How does one get a set of refrigerator gauges on this beast to tell if it is low on refrigerant or not?
Those are my questions for now....maybe when I know more, I'll have more questions.
Thanks
My DP (identified below) has a rear-facing radiator and it has two heat exchangers on the sides at the rear. One of them (right side/passenger side) when viewed from the outside appears to be a heat exchanger with no visible fans and when viewed from below, all I can see is a galvanized sheet metal box with a rectangular hole in it and some hardware cloth over the hole to keep varmints out. When the A/C is on, air is being pulled through this condenser from outside the coach and exhausted out the rectangular hole in the bottom and I can feel heat in the air flow. Can't see what is in the box, but the ductwork comes out the rear of the box and goes up into the ceiling at the rear so I assume the evaporator coil and one or more compressors (more about that later) are in this box. The cold air return is under the bed w/filter in the same area and also enters this box.
On the left side, I see a similar sized heat exchanger from the outside, but this one has 2 electric fans attached to it (on the outside between the heat exchanger and the coach grillwork) that either blow air through or draw air through the exchanger. These fans resemble the fans available as aftermarket equipment for auto radiators. Pancake design, not very deep, several blades and a plastic blade guard. No box on this side, from underneath I can see the rear of the heat exchanger and attached to the bottom of it is a long cylindrical tube about 1 1/2" in dia, maybe 2" with some sort of "slide" mechanism that could be a "reversing valve" to change from heat pump to A/C. Nothing else on this side, no sign of a compressor.
The thermostat is one I am sure is made for this type system having an A/C mode, a gas heat mode, and a heat (heatpump) mode. Cool, not cold, air comes from my ceiling vents when the unit is in the A/C mode. I'm not sure if it is working "good" or not. I'm wondering if both compressors are running or if it needs additional refrigerant. As I read thru the forum, they appear to be "marginal" at best. Now the questions:
(1) My EMS panel where it indicates what loads have been shed in reduced power situations, I see A/C compressor #2 listed as one of the things that is powered down, depending on available supply and demand. Where is this #2 compressor and does it run all the time if not shut down by the EMS? Why 2 in the first place? How does one know if both are running? My EMS panel shows a green light beside all the "sheddable loads" when plugged into 50A service and I assume that that means this 2nd compressor is "enabled."
(2) I've never seen any action out of the left side heat exchanger/fans. The fans have never been on. Tried it again today. Should they be on all the time? Do they come on as "reserve" as a function of outside air temperature? Should they be running when the fan on the other side is running? Are they linked with operation of the #2 compressor? Does this side work only in the "heat" mode? I didn't try that. Is this thing even a part of the A/C system or is it a transmission cooler?
(3) Is the cylindrical thingy at the bottom of the left side heat exchanger a reversing valve or something else?
(4) Is there anything that needs service or maintenance inside the box on the right side and, if so, how in the heck does one gain access to it?
(5) How does one get a set of refrigerator gauges on this beast to tell if it is low on refrigerant or not?
Those are my questions for now....maybe when I know more, I'll have more questions.
Thanks