How much baseboard?

[Ross]

Time to start thinking about installing the Proheat.  Anyone out there in the heating business have a guideline on how much baseboard would be about right for a 45K Proheat?  For the time being, the plan is to just loop the proheat through the baseboard system and a small expansion tank so I can get some hydronic heat going for the winter.  I'll use the propane water heater and electric block heater until spring, then I'll install a proper system with a larger expansion tank and zone pumps for Heat, hot water and engine preheat.

For available wall space, on the passenger side I have 14 feet in the liveing room/dining room, 3 feet next to the toilet and 8 feet in the bedroom.  On the driver side, I have 6 feet in the living room behind the couch and 8 feet in the bedroom.  3 feet beside the toilet is probably not worth messing with.  So does this sound like enough baseboard...or not enough?

Also...Is it cool to plumb the baseboards with PEX?  It seems to have a high enough heat rating.

Thanks....Ross

[belfert]

PEX will be fine for heat.  Radiant heat in concrete floors is all done with PEX these days.

Brian Elfert

[kyle4501]

Hey Ross,
Personally, I don't like cold bathrooms,    so I'd definitely have heat in there. 

What is the heat rating of your baseboard heaters?

[Ross]

I don't have the baseboards yet.  They are probably rated so many BTU per foot though.  I didn't think of that.  I'll check it out on the next Lowes run.  I don't mind a cold bathroom as much as ccccccold tile.  I thought of staping some pex under the bathroom floor and looping through that on the way back to the front of the bus.

Ross

[kyle4501]

If you could get Buddy trained to sleep on the floor, you wouldn't have to worry about warm floors! 

[Nick Badame Refrig/ACC]

Hi Ross,

With your bus complete allready, You would be better off with Hydronic kick space heaters. Theese heaters have 1/2"

supply and returns, with the blowers running off 115v. A company by the name of Beacon/Morris makes some good units.

I belive they come in 3 sizes, 4200btu / 8400btu / and 11400btu's.    Site: http://www.beacon-morris.com/

Nick-

[kyle4501]

Ross, How is your coach heated now? How well is it insulated?

The heat required to raise the temp inside is easy to determine, it goes something like this -

On a cold night, put a 1500 watt electric heater (set on high) inside the coach (keep it a safe distance from combustables) & close it up.

Record the inside bus temp. & the outside bus temp & the time (should be the same at the start).

Several hours later, record the temps & time again.

This information can be used to determine the heat required to raise the temp inside your coach above ambient.

Then you will be able to know how many heaters are required for your needs.

Sounds  simple, right??

[Ross]

Hi Ross,

With your bus complete allready, You would be better off with Hydronic kick space heaters. Theese heaters have 1/2"

supply and returns, with the blowers running off 115v. A company by the name of Beacon/Morris makes some good units.

I belive they come in 3 sizes, 4200btu / 8400btu / and 11400btu's.    Site: http://www.beacon-morris.com/

Nick-

Two reasons for not using kick space heaters, Nick.  (1) I don't want to spend the money on them and (2) It's 3 more fans running and drawing DC from the house bank.  Installing the baseboards will be easy.  All I have to do is punch a few holes in the floor and connect the baseboards down in the bays.  The baseboards in the bedroom can be connected above the floor under the bed.  Should be a pretty easy install.

Ross

[Ross]

Ross, How is your coach heated now? How well is it insulated?

It's insulated pretty well.  I used blue foam boards.  I did heat it during the winter in NH for a little while with 3 1500 watt heaters during construction and they would cycle on and off.  I did that until I got the elctric bill. 

I'm inclined to just install baseboard where I have space for it with a loop under the bathroom floor.  That loop should also keep the tank bay above freezing....Although I don't plan on spending a whole lot of time near freezing temps.

Ross 

[DrivingMissLazy]

I have always heard that it is very nearly impossible to get enough baseboard heaters installed to warm a coach. Especially when the temperature gets to freezing or below. Apparently just not enough wall space available to provide an adequate amount of heat.

Before you commit to this may I suggest that you get some input directly from some nuts that have successfully done this.
Richard

[Stan]

The common baseboard  (3/4" tube - 2" fin) that I used was 900 BTUs per foot but I expect it is available in different ratings. If you bus is well insulated and you are not going into extreme cold weather you can get away with 25 - 30 feet if you run the boiler at 185* F.

There are many other factors to consider when you make your permanent system.  Consider floor insulation or heated bays, number and type of windows and window covering, air circulation nside the bus, how often the door will be opened, method to control flow to engine and  domestic water heater.

[kyle4501]

I did heat it during the winter in NH for a little while with 3 1500 watt heaters during construction and they would cycle on and off. I did that until I got the elctric bill.

Ross

LOL, I had the same experience the first winter when I used the engine block heaters for a few weeks straight until I could change the antifreeze .... OUCH! 

1500W times 3 equals 4500watts which equals ~15353 BTUs

15353 divided by 900BTU/FT equals ~17 feet of base board.

However, the electric heaters were heating the air in the middle of the bus. The baseboards will be heating air that will soon be cooled by the  outside wall & windows, so it won't feel as warm until the walls are suficiently warm.

Radiant base board heat 'feels' different than forced air heating.

You could always start with as much baseboard heat as you can fit in & add a toe Kick heater for occasional use at a later date.

[Ross]

I have the wall space for 41 feet of radiator + I can do coils under the tile floor.  That should just about match the capacity of the Proheat.  I went to Lowes today and the guy in the plumbing dept didn't know what I meant when I asked for hot water baseboards.  Must not be a common thing in NC.

Ross

[Nick Badame Refrig/ACC]

Ross,

For baseboard finned fixtures,

Try a Johnstone Supply or  R E Michael Supply. They are nationwide and in most yellow pages.

As far as size and how many feet.....As  many as you can fit will be just enough!

Give me a call if you need to, you got my #

Nick-

[oldmansax]

Ross:
This is more complicated than it appears at first glance & Nick may be able to give you some more pointers.
That said, I am looking at putting baseboard in my MCI 7. I ran a heat/cooling load using a Manual J computer program I have for my HVAC business. Using metal walls & the insulation values (R-3) that came in the bus, I came up with 37,455 BTU for heat and 21,820 BTU for cooling. Legal Disclaimer: This is for MY BUS. YOUR RESULTS MAY VARY! 
According to the specs published by HeatTrim, regular baseboard will deliver the following values:

G.P.M.                   Average water temperature
   160F   170F   180F   190F   200F   210F   220F
1   430   500   560   630   690   760   820
4   460   530   590   670   730   800   870




They also have a commercial product with the following values:

G.P.M.            Average water temperature
   160F   170F   180F   190F   200F   210F   220F
1   620   710   800   890   980   1080   1170
4   650   750   850   940   1040   1140   1240



Using these values I would need a minimum 67 feet of regular baseboard if I have 180F water @ 1 G.P.M. If I use the commercial product I would need about 47 feet.

You can extrapolate your own needs based on the table.

Hope this helps!

TOM