kitchen hutch hot

[Spikebox]

I have the same issue with my 313 and it was 37 degrees here in MT this morning so I had to run furnace. Wonder if this something that can be fixed remotely as I can't be without the camper for a week at this point???

[cpotts]

Contact Grand Design. I contacted them through their website. I had a response the very next morning.
I'm sure they will work with you.

[guidocat]

Hi gang,

I've been working on this issue with my 313 RLTS as well. I was interested to see if anyone had an experience different than mine.

I just made an account this morning. Is this forum still active, and is anyone still interested?

Guido

[guidocat]

I'll just give this one more bump before I hit the old dusty trail.

on the 313RLTS. The inside of the drawers above the furnace will exceed 140 degrees F and the countertops and the lower part of the backsplash wall will also reach between 100 and 140 degrees in places after 45 minutes of continuous running. To make a long tedious story short. I left the RV with the dealer for a week and Grand Design responded that it was a design decision and not an issue.

In my opinion, that is an issue. 200 degree wood will not spontaneously combust, but the relative humidity inside the cabinet and wall fall into the single digits when the temperature reaches the 140 degree region, so the wood in that area will suffer.

I took quite a bit of data and I have engineered a fair solution to the collecting heat.

If there is an audience, I'd be happy to share the solution. It looks like only a few have used their unit in cold enough weather for it to be an issue based on this thread, and their free accounts might have already expired.

Did anyone else hear that GD was bought by Winnebago? Did you know that the name is derived from the ancient Viking concept of the Winter Bagel? Which is exactly what it sounds like.

[Bob/OlallaWA]

Mine also heated things up while running for a long time. Noticed it more on the shower wall than the hutch. I bought a tube of high temp silicone and filled in the open areas of the furnace frame where I could reach. It did help a lot.

[TucsonJim]

I'll just give this one more bump before I hit the old dusty trail.

on the 313RLTS. The inside of the drawers above the furnace will exceed 140 degrees F and the countertops and the lower part of the backsplash wall will also reach between 100 and 140 degrees in places after 45 minutes of continuous running. To make a long tedious story short. I left the RV with the dealer for a week and Grand Design responded that it was a design decision and not an issue.

In my opinion, that is an issue. 200 degree wood will not spontaneously combust, but the relative humidity inside the cabinet and wall fall into the single digits when the temperature reaches the 140 degree region, so the wood in that area will suffer.

I took quite a bit of data and I have engineered a fair solution to the collecting heat.

If there is an audience, I'd be happy to share the solution. It looks like only a few have used their unit in cold enough weather for it to be an issue based on this thread, and their free accounts might have already expired.

Did anyone else hear that GD was bought by Winnebago? Did you know that the name is derived from the ancient Viking concept of the Winter Bagel? Which is exactly what it sounds like.

We hit single digit humidity many times each year. It was so bad that our 2014 cabinets shrank and the vinyl covering puckered. GD finally started having their supplier kiln dry the wood and replaced our cabinets in 2015! I don't think they have that problem anymore though.

Jim

[guidocat]

Thanks for the replies gang.

Bob, when I returned the RV to the dealer, they used tin tape all over the furnace box, and they really did cover the thing to the point of nearly airtight. There may have been an improvement, I hadn't spent enough time with it prior to know.

Jim, that's good to know about the problems with shrinkage. It makes me feel like my quest to solve this problem is worthwhile.

I tried a few things before settling on a solution. I placed thermocouples in strategic places in the cabinet and walls above the furnace. The real trouble was that waste heat was collecting inside the wall between the furnace and the shower as Bob noted. The air inside the wall was in excess of 150 degrees after about 30-45 minutes of continuous run. I have plots of the actual data if you are interested. I stopped the test after 45 minutes as the temperature was continuing to rise. These temperatures are still far from flashpoint, so there was no safety hazard, but relative humidity was waaaaaaay below what wood would enjoy.

So, the problem is tons and tons of waste heat with nowhere for it to go except through the walls. As I mentioned, the wall and countertop were in excess of 140 degrees on the surface, so there was some heat sinking going on, but at the cost of the moisture in the wood. Removing the drawers didn't help either since the heat was rising rapidly and there was no reason for it to go anywhere but up.

After some more data collection I put some small 120mm fans just below the upper cabinet on the splashback wall using a 12V power supply that is triggered by the thermostat. The remarkable thing is that those fans are blowing out 140-150 degree air that was previously just hanging out in the wall. So essentially, I was able to protect the wood from extreme heat and I increased the efficiency of my heater pretty significantly. I don't know how much, but some. Instead of that 150 degree air getting pumped back into the furnace or just heating up my trim, I 'm getting it out into the living space.

I hope this helped someone.

So where are all the RV engineer types living? What's the popular forum for the problem solvers?

Thanks for the tips gang.

Guico

[ouchkernel]

Thanks for the replies gang.

Bob, when I returned the RV to the dealer, they used tin tape all over the furnace box, and they really did cover the thing to the point of nearly airtight. There may have been an improvement, I hadn't spent enough time with it prior to know.

Jim, that's good to know about the problems with shrinkage. It makes me feel like my quest to solve this problem is worthwhile.

I tried a few things before settling on a solution. I placed thermocouples in strategic places in the cabinet and walls above the furnace. The real trouble was that waste heat was collecting inside the wall between the furnace and the shower as Bob noted. The air inside the wall was in excess of 150 degrees after about 30-45 minutes of continuous run. I have plots of the actual data if you are interested. I stopped the test after 45 minutes as the temperature was continuing to rise. These temperatures are still far from flashpoint, so there was no safety hazard, but relative humidity was waaaaaaay below what wood would enjoy.

So, the problem is tons and tons of waste heat with nowhere for it to go except through the walls. As I mentioned, the wall and countertop were in excess of 140 degrees on the surface, so there was some heat sinking going on, but at the cost of the moisture in the wood. Removing the drawers didn't help either since the heat was rising rapidly and there was no reason for it to go anywhere but up.

After some more data collection I put some small 120mm fans just below the upper cabinet on the splashback wall using a 12V power supply that is triggered by the thermostat. The remarkable thing is that those fans are blowing out 140-150 degree air that was previously just hanging out in the wall. So essentially, I was able to protect the wood from extreme heat and I increased the efficiency of my heater pretty significantly. I don't know how much, but some. Instead of that 150 degree air getting pumped back into the furnace or just heating up my trim, I 'm getting it out into the living space.

I hope this helped someone.

So where are all the RV engineer types living? What's the popular forum for the problem solvers?

Thanks for the tips gang.

Guico

Hi,

I am seeing the same thing with my 315RLTS. Do you have any pictures of what you did? The 12V power supply did you just tap into the inverter or are you using batteries? Do you have a part list?

[MikeandLibby]

Same issue here with my 315RLTS. Hutch gets super hot. My main issue is our thermostat thinks it's 8-10 degrees hotter than it really is. I told GD about it and they promptly sent me a new thermostat (new touch version) but of curse that didn't solve the problem. After reading these posts it looks like the issue is the excessive heat escaping from the furnace box. That would definitely explain the hot hutch and the thermostat showing the wrong temp. The underbelly is exposed behind the hutch via a hole for ducts and wiring so at least it's keeping my underbelly warm.

Since I'm currently full-timing, I'm thinking of pulling the cupboard panel off the hutch and accessing the furnace to seal it up. We'll see....


Sent from my iPad using Tapatalk

[guidocat]

Hey gang,

sorry for not getting back to you sooner. I'll try to give a quick explanation of the problem and solution and I can explain how I addressed it.

I'll start by explaining the problem, and if there is an audience I'll go through the resolution.

From my experience, there is nothing that can be done to appreciably change the amount of heat that is being generated from the furnace and released into the wooden cabinet. The furnace, when operating, contains 650 degree air. The metal shell of the furnace becomes similarly hot. Metal is a fairly good radiator of heat and thus the air and surfaces surrounding the furnace began to warm. This is independent of any air leaking from the furnace into the cabinet. Through my experiences, i found that reducing air leakage didn't change the temperature rise within the cabinet in any measurable way. As long at the furnace is running, heat is being radiated or convected into the air within the cabinet.

So, where does that heat go? Heat rises, so none of that heat is going into your basement. There is a duct that empties into the basement area, so the basement gets very warm. You noted that there is an opening connecting the basement to the air inside that cabinet. Sadly, the heat that is released into the basement wants to rise, so that heat is actually moving upward into that same cabinet. This is a contributor to the temperature of the air inside the cabinet as well. If you take a drawer out of the cabinet, you can see that the interior wall separating the kitchen from the bathroom is open inside the cabinet. This allows for the heat to rise further and fill the wall cavity behind the countertop and up behind the china cabinet. This is where the heat collects. As this cavity continues to warm, it conceptually fills up like a bucket starting at the top and moving down until the entire cabinet is filled with very warm, dry air. Wood is a good insulator, and lots and lots of heat is being generated, so heat will continue to accumulate until the heat transference out of the cavity equals the heat being introduced to the cavity.

A good way to baseline your problem is to take a digital thermometer and put it in the wide drawer above the furnace. Start the furnace after it has been off for awhile and run it continuously for an hour. Not the temperature before and after the experiment. You will likely find that after about 30-45 minutes the air inside the drawer will get above 150 degrees and the humidity will drop into the single digits.

Mike and Libby, let me know if this is helping. Also, this fix I will continue describing will fix the malfunctioning thermostat too. We are fulltiming as well, and now we can set the thermostat to 75 and its only about 2 degrees off instead of 15.