[NealCarney]

@NealCarney - really excellent work! Happy my installation helped. A couple of observations:

• Our Comfort Hot tank does not get super hot. It did the first time I fired it up, it turned out I did not fill the entire system with enough coolant. When firing up the system the tank drained a little to fill the lines and got very hot. I topped it off to 1" below the top. Since then the tank is warm but not super hot.
• Same applied to the first heat exchanger when we first fired it up wow it was hot. Once we had enough coolant in the overall system it is hot but not scolding.
• I wish I had the Auxiliary Heater Prep package as I did not do an engine loop, it would be nice to have hot water when we stop for lunch. But it only takes about 5 minutes to heat up hot water.
• Factory fuel pickup line issues. I used the factory fuel pickup line and have been using the system since December 2020; as high as 10k feet and in very cold environments. Before we leave on a trip I fire up the system (using constant heat) and it routinely takes a couple of times to kick in. The Rixen "webpage" is helpful to see that the fuel goes to zero; then I let the furnace wind down and restart. After that we have had no problems on the road. When on the road and at camp make sure you have at least a quarter to half tank of gas.
• When first using the system carefully check all coolant line clamps, especially on the air handler as they are copper connectors and not as "secure" as the brass coolant tank connectors. I used a hose clamp and had a very small leak from the lower connection after a winter trip. I see you have constant tension clamp on the coolant tank, did you use them on the air handler also?
• Have used the electric element a few times, mostly when visiting family back east in the winter and have the van on shore power over night.
• Overall we love the system and the support from the Rixen team is top notch.

Thanks for the observations @nealcallan.

• After I started up the system and ran it for a bit, I made sure to check the coolant level and top off; about 1” below, like you. I will check it again just to be safe.
• Thanks for sharing the positive experience with the factory fuel pickup. It’s also working fine for me, and I have plenty of other stuff to do, so I’m in no rush to install a smaller tube.
• The system has been installed for about three months and no leaks yet; I monitor regularly since things can change. I did exclusively use constant tension clamps (no worm drive clamps) including on the air handler; no issues. By the way, I forgot to mention in my post that having one of the flexible hose clamp pliers shown in the pic below is really a must for the constant tension clamps. Makes your life much easier since you are working in confined spaces.
• Getting ready for a two-week trip to SC/GA/FL and have booked most nights in state parks (aside from wedding we are attending). Looking forward to utilizing the Rixen system a little bit more. Happy that our rooftop AC is working well because we will need it on this trip!

 

[nealcallan]

Thanks for the observations @nealcallan.

• After I started up the system and ran it for a bit, I made sure to check the coolant level and top off; about 1” below, like you. I will check it again just to be safe.
• Thanks for sharing the positive experience with the factory fuel pickup. It’s also working fine for me, and I have plenty of other stuff to do, so I’m in no rush to install a smaller tube.
• The system has been installed for about three months and no leaks yet; I monitor regularly since things can change. I did exclusively use constant tension clamps (no worm drive clamps) including on the air handler; no issues. By the way, I forgot to mention in my post that having one of the flexible hose clamp pliers shown in the pic below is really a must for the constant tension clamps. Makes your life much easier since you are working in confined spaces.
• Getting ready for a two-week trip to SC/GA/FL and have booked most nights in state parks (aside from wedding we are attending). Looking forward to utilizing the Rixen system a little bit more. Happy that our rooftop AC is working well because we will need it on this trip!
• View attachment 175626

Hi @NealCarney - If I was to redo the project I'd go with constant tension clamp. I was unfamiliar with these types of system and just went with hose clamps out of convenience. Overall only just the one small leak and I do a check after each trip. Those hose clamp pliers are very cool, have not seen those before. Have fun on the trip - stay cool!
Take Care

 

[NealCarney]

Hi @NealCarney - If I was to redo the project I'd go with constant tension clamp. I was unfamiliar with these types of system and just went with hose clamps out of convenience. Overall only just the one small leak and I do a check after each trip. Those hose clamp pliers are very cool, have not seen those before. Have fun on the trip - stay cool!
Take Care

Good point; for any others following this thread that are thinking about an install, be sure to use the constant tension clamps.

Side point...when you had the leak and needed to fix, did you drain the system to install the new clamp, or just clamp off that section hose? Looking to the future of my build, I will need to temporarily disconnect my system at some point and need to tackle draining the system. I have a drill operated transfer pump which I can use to evacuate the coolant in the Comfort Hot, but that still leaves a fair amount in the lines. I could not find a good/compact bleeder/needle valve which I could install in the hose lines, so I have no ability to drain other than disconnecting the hoses at the furnace, which is the low point. Would be nice to have a drain valve somewhere near the furnace.

 

[NealCarney]

• Our Comfort Hot tank does not get super hot. It did the first time I fired it up, it turned out I did not fill the entire system with enough coolant. When firing up the system the tank drained a little to fill the lines and got very hot. I topped it off to 1" below the top. Since then the tank is warm but not super hot.
• Same applied to the first heat exchanger when we first fired it up wow it was hot. Once we had enough coolant in the overall system it is hot but not scolding.

Quick update on this. I checked my coolant level and it was still at about 1" below the top, so no loss after the initial air bleeding. I ran the furnace and noted on the web interface that the glycol output temperature was 178F. Checked the exterior temperature of the Comfort Hot with my IR gun and obtained readings between165F and 170F. A little tricky since aluminum emissivity is low and values vary pretty widely based on type of aluminum, so I shot the gun at the decal on the tank. To me, it makes sense that the tank temperature would be only slightly below the furnace glycol output temperature. I have a pretty short coolant line from furnace to tank, and aluminum is a pretty good heat conductor. It was more difficult to get a good reading on the water heat exchanger (just below the tank), but it felt pretty much the same and the unadjusted gun readings were about the same.

I have a 1/2" baltic birch bed platform immediately above the Comfort Hot tank. I took readings on the plywood and noted that the area directly above the tank was 7F-10F warmer than the remainder of the bed. The good news is the area with the heat differential was pretty much limited to the footprint of the tank. Based on this observation, I plan to place insulation directly above the tank at a minimum; possibly all the way around the tank. Fortunately I sleep on that side of the bed and I prefer more heat than my wife, who prefers an Arctic environment. Maybe I will make the insulation easily removable so that in the Winter I will have extra heat for my toes.

 

[Brandon]

Quick update on this. I checked my coolant level and it was still at about 1" below the top, so no loss after the initial air bleeding. I ran the furnace and noted on the web interface that the glycol output temperature was 178F. Checked the exterior temperature of the Comfort Hot with my IR gun and obtained readings between165F and 170F. A little tricky since aluminum emissivity is low and values vary pretty widely based on type of aluminum, so I shot the gun at the decal on the tank. To me, it makes sense that the tank temperature would be only slightly below the furnace glycol output temperature. I have a pretty short coolant line from furnace to tank, and aluminum is a pretty good heat conductor. It was more difficult to get a good reading on the water heat exchanger (just below the tank), but it felt pretty much the same and the unadjusted gun readings were about the same.

I have a 1/2" baltic birch bed platform immediately above the Comfort Hot tank. I took readings on the plywood and noted that the area directly above the tank was 7F-10F warmer than the remainder of the bed. The good news is the area with the heat differential was pretty much limited to the footprint of the tank. Based on this observation, I plan to place insulation directly above the tank at a minimum; possibly all the way around the tank. Fortunately I sleep on that side of the bed and I prefer more heat than my wife, who prefers an Arctic environment. Maybe I will make the insulation easily removable so that in the Winter I will have extra heat for my toes.

I have been thinking about an insulated box around the system to keep the heat in. Was worried it would get to hot but in thinking it should just get up to the max 170-180, what ever the max temp it. Insulate tank and heat exchangers only. Just need a good fire resistant insulator to put inside box. Also want to insulate it from the side of the van. Do not want to cook the paint on the side of the van.

 

[mototreks]

I wish I had the Auxiliary Heater Prep package as I did not do an engine loop, it would be nice to have hot water when we stop for lunch. But it only takes about 5 minutes to heat up hot water.

Would it be possible to heat the system while driving with an inverter (powered by the alternator) via 110v?

 

[NealCarney]

Would it be possible to heat the system while driving with an inverter (powered by the alternator) via 110v?

Yes, even without the engine loop heat exchanger you should be able to heat the system while driving with either 110V or the furnace. The electric heater element consumption seems be around 1.3kW (I think the spec says 1.5kW), so your alternator and/or battery consumption would be a little or a lot more depending on your system components/efficiency. You could pre-heat the system on shore power prior to departure and then you would just need energy to maintain the temperature.

 

[nealcallan]

Good point; for any others following this thread that are thinking about an install, be sure to use the constant tension clamps.

Side point...when you had the leak and needed to fix, did you drain the system to install the new clamp, or just clamp off that section hose? Looking to the future of my build, I will need to temporarily disconnect my system at some point and need to tackle draining the system. I have a drill operated transfer pump which I can use to evacuate the coolant in the Comfort Hot, but that still leaves a fair amount in the lines. I could not find a good/compact bleeder/needle valve which I could install in the hose lines, so I have no ability to drain other than disconnecting the hoses at the furnace, which is the low point. Would be nice to have a drain valve somewhere near the furnace.

Hi @NealCarney - I did drain the system once when adding an additional coolant line. I disconnected at the furnace over a 3 gallon bucket; wore a pair of those yellow kitchen gloves. A little messy but managed to capture all the coolant in the bucket. I did see a Sprinter install from a youtuber called "Dares Drives" where he used a 3/4" boiler valve for draining the coolant.

 

[mikemikemike]

What type of glycol are you using in the system? Rixen said use standard automotive 50/50 green blend, but I would have thought a food grade glycol would have been preferred. Also if it vents any fluid outside through vent hose, probably not good to just be dropping automotive antifreeze on the ground.

 

[nealcallan]

What type of glycol are you using in the system? Rixen said use standard automotive 50/50 green blend, but I would have thought a food grade glycol would have been preferred. Also if it vents any fluid outside through vent hose, probably not good to just be dropping automotive antifreeze on the ground.

I use an automotive 50-50 blend as recommended by Rixen. Certainly you can use a food grade propylene glycol, it is safer to handle, non toxic... Not sure of the cost though. I have never vented any glycol via the expansion tank vent. More of a fail safe, and you have bigger problems if it vents any decent quantity.

 

[Brandon]

I use an automotive 50-50 blend as recommended by Rixen. Certainly you can use a food grade propylene glycol, it is safer to handle, non toxic... Not sure of the cost though. I have never vented any glycol via the expansion tank vent. More of a fail safe, and you have bigger problems if it vents any decent quantity.

I had not thought about the type of Glycol for my system but now I may use the food grade stuff just incase I got a leak inside when I'm not there and my dog decides to lick it up. Yes if it leaks that much I have a big problem but I would prefer not to poison my dog while I'm at it. Need to ask Rixen if we are ok to use that stuff.

 

[DustyShadow]

There seems to be limited installation documentation on the Rixen‘s site apart from diagrams and the Espar manual. Where do I find the guidance from Rixen’s for things like what type of glycol to use? I haven’t ordered the system yet, maybe you only get access after ordering?

 

[Brandon]

There seems to be limited installation documentation on the Rixen‘s site apart from diagrams and the Espar manual. Where do I find the guidance from Rixen’s for things like what type of glycol to use? I haven’t ordered the system yet, maybe you only get access after ordering?

Call them. They are very helpful and answered all my questions on a couple phone calls before I ordered.

 

[brío]

maybe you only get access after ordering?

Over the years, I have found Jim Rixen to be one of the most accessible, generous, and knowledgable venders I have ever dealt with. Try an email or phone call.

 

[mikemikemike]

There seems to be limited installation documentation on the Rixen‘s site apart from diagrams and the Espar manual. Where do I find the guidance from Rixen’s for things like what type of glycol to use? I haven’t ordered the system yet, maybe you only get access after ordering?

I just asked yesterday via email and got a response from Andrew to use 50/50 green automotive coolant. I replied back asking about food grade gylcol, and haven't heard back yet. The food grade gylcol on Amazon is around $40/gal. Andrew pointed out it takes about 3.7 gallons to fill the system.

I'm guessing the chances of any leaks in the hot water heat exchange are very rare. And I'm guessing you'd notice pretty quick if you are using green antifreeze? 🤷‍♂️

 

[brío]

A properly installed system will not leak.
If you are worried, put a moisture alarm under your tank.

 

[timreg2]

I just asked yesterday via email and got a response from Andrew to use 50/50 green automotive coolant. I replied back asking about food grade gylcol, and haven't heard back yet. The food grade gylcol on Amazon is around $40/gal. Andrew pointed out it takes about 3.7 gallons to fill the system.

I'm guessing the chances of any leaks in the hot water heat exchange are very rare. And I'm guessing you'd notice pretty quick if you are using green antifreeze? 🤷‍♂️

I'm curious about this as well as I'll be picking up my Rixens system this month.

I wonder what RV antifreeze has to offer. It's food safe and is available everywhere. There must be a variety of formulas available as the prices run from $4 - $40 a gallon.

 

[brío]

I'm curious about this as well as I'll be picking up my Rixens system this month.

I wonder what RV antifreeze has to offer. It's food safe and is available everywhere. There must be a variety of formulas available as the prices run from $4 - $40 a gallon.

I am not certain, but I think that the pink stuff turns to slush, rather than remaining liquid. Might not be desirable. 🤷‍♂️

 

[Michael Ophus]

The cheap RV antifreeze is grain alcohol based, Lots of people use it.

 

[timreg2]

The cheap RV antifreeze is grain alcohol based, Lots of people use it.

Yeah, I see the cheapest at HD ($4) is ethylene glycol:

PRIME GUARD 128 fl. oz. Ethyl Alcohol -50°F Universal Non- Potable RV Antifreeze 95806 - The Home Depot

PRIME GUARD minus 50°F RV and Marine Antifreeze is a premium winterizing formulation safe for use in all types of potable water and plumbing systems. This ethyl alcohol formula is safe on copper, brass

www.homedepot.com

Then they have 100% propylene glycol for $8:

SPLASH 128 fl. oz. RV/Marine AntiFreeze Minus 75°F 619535-35 - The Home Depot

Winterize your recreational vehicles, boats, spas, hot tubs, pools, vacation homes and campers with SPLASH non-ethylene antifreeze. SPLASH Marine Antifreeze is made with a plant-derived additive for minus

www.homedepot.com

And this corrosion resistant one for $40:

Hercules Cryo-Tek 1 Gal. Non-Toxic Corrosion-Resistant Antifreeze 35253 - The Home Depot

Hercules - Cryo-Tek 1-Gallon Antifreeze - For heating systems requiring freeze protection as well as corrosion prevention. This non-flammable, odorless liquid is also non-toxic. - THD SKU# 654899

www.homedepot.com

All are non-toxic.

When I pickup my system from Rixens I will try to get more info on the possible use of a non-toxic variant.