| Author |
Message |
David Anderson (66.90.192.70)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 15, 2003 - 12:10 pm: | |
I have 3 7000 btu fan heaters in the front of my Eagle. One in the step well, one in the lounge, one in the kitchen. I think I need more exchangers and am considering radiator strips behind the couch and under the booth so I can get faster heat transfer. This will give me a longer "furnace on" cycle and shorter "pump running" cycles. In short it would heat the coach to the selected T-stat temperature quicker.
Any thoughts on this? How have most of you guys done yours?
David Anderson |
David Anderson (66.90.198.124)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 15, 2003 - 6:42 pm: | |
Another question,
If I do put fin heaters, I need a 12 volt 1" 3way valve to divert heated coolant away from the fin heaters while heating the water heater traveling down the road and not requiring heat in the coach.
I've found all kinds of 3 way valves, but they all are 24volt AC.
Anyone have a source??
David Anderson |
Geoff (Geoff) (66.238.120.89)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 16, 2003 - 8:51 am: | |
I have a Webasto I haven't completely finished installing in my bus, but I have used it. I bought two large school bus heater boxes (with double fans) from Ronthebusnut, I don't know the BTU's. I also bought a small heater box made by Red Dot. All my heaters are hooked up in parallel and have individual shut off valves (brass gate valves with bleeders). If you hook them up in the same loop (in series) then you would need the diverter valve you asked about. If you are looking for radiant heat without the fans you should check out a store that sells hydronic heating products for the home-- they would have the radiant heaters you need.
--Geoff
'82 RTS CA |
Tom Caffrey (Pvcces) (64.114.233.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 16, 2003 - 11:18 pm: | |
David, IIRC, residential baseboard heaters used in hydronic systems provide 810 btu per foot if the water is 180° and the air temperature of the room is 70°. This means that an 8 foot heater produces a little more heat than a portable electric heater.
The toughest part about dealing with hydronic heating systems is getting enough radiator for quick warming of the room. Many people wind up never turning the thermostat down because the room takes too long to warm up.
Unit heaters (toe kick or Red Dot heaters) are the best chance to get the btu output high enough so that people don't leave the heat turned up all or most of the time.
The trick is to figure how much space you have, how much patience you have and how much battery you have. You weigh each of these things and try to strike the right balance for you.
BTW, I believe that some of these unit heaters go something like 20,000 btu or the equivelant of about 24 feet of baseboard heaters.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
David Anderson (66.90.199.40)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 17, 2003 - 12:20 am: | |
Geoff and Tom,
I already have 6 fan heaters, (5 in the bus, 1 in the plumbing bay) The webasto specs only allow 6. I guess I could add more with a separate cicuit and relay, but I don't want to give up any more battery current.
What I found in 20 degree weather, the furnance would run a while and cycle off when high temp was attained. The three 7000btu fan heaters never got the lounge area above 65 (T-stat setting); consquently, they always ran. I'm getting hot air from the fans but feel like I need more heat transfer in the lounge area. That's why I'm considering finned radiators under the couch, under the booth, and on the wall next to copilot chair.
The bedroom and bathroom zone easily had enough temp rise to reach the T-stat settings. They only have one heater in each room.
The dilema with finned radiators is when driving down the road with no coach heat needed, but the pump running to transfer heat to the Sealand water heater exchanger, hot coolant would be going through the radiators, thus the need for the 3 way valve.
I have Peninsula double pane windows and the bus is spray foamed. It just seemed too cool in the front of the bus. I figured this would happen when designing the layout because of the windows, front windshield, and door, so now I'm just brainstorming to improve the engineering.
If I do add radiators I have to decide if I want to keep my manual valve, (stop and open bay to divert) or get an electric valve (push button on dash)
Wrico has one for $150. I can't find one anywhere else that has a 12 volt coil.
Since I have 6 7000btu heaters in a 40000 btu system, would it be folly for me to add about 7000 btu more of finned radiators?
My thinking is no because
1. the furnace is cycling off before the fan heaters reach the T-stat setting.
2. The bed and bath heaters heat the rooms so much quicker, cycling off, and allowing more btu's to be used up front, if needed.
However, I am not a HVAC guy and may be all wrong.
FYI, I have the high volume pump in my system because the total length is 110'. So, I should be getting good flow through the 3/4' pipe. |
Tom Caffrey (Pvcces) (64.114.233.148)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 17, 2003 - 10:12 pm: | |
David, what I was getting at in my post is if you need more heat that is easily controlled, the unit heater is the only way to get it in a small space.
If you add the finned radiators, you will only get a percentage change in the total heat output, and I don't think you will be all that happy with the improvement.
However, if you took out a 7,000 btu unit and installed a 20,000 btu one in it's place, you would get double the increase compared to the finned units and the thermostat would be able to control it.
Do that twice and you would have an increase of 26,000 btu, which could take all the heat the Webasto could put out.
Judging from your remarks about how hard it is to heat your lounge area, I got to wondering if you don't have a bad heat loss in that area. There are lots of ways to lose heat.
An uninsulated floor is one way you can really get surprised. Usually, there are air migration problems around the door, through the defrost system and the original heating system.
And usually, the lounge area will have a lot more glass exposure. Also, the front of these old GMs are not even insulated under the dash, so it's real hard to keep them warm.
Good luck!
Tom Caffrey PD4106-2576
Suncatcher |
FAST FRED (209.26.115.206)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 18, 2003 - 5:48 am: | |
The door on most GM is DESIGNED to vent air that the two 80A blowers sucked in .
For severe winter ops the use if a bathroom rug from Sears (or?) is great.
Can be cut & trimed with out unraveling.
They insulate , and can be stuffed into a commercial washer a few times to get rid of winter mud & snow/water spots.
Most GM have huge glass areas , so the plastic over the window trick is a great help.
Just unlatch the window Emerg Exit , swing window out slightly , drag plastic all around & close window. Trim inside & your done for a season. Works for screening in summer too.
Easier to leave the 0'F and head to the warm places.
FAST FRED |
RayC (142.165.222.227)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 18, 2003 - 10:02 am: | |
One of the things I am looking at in my own conversion is my bus came with 1" copper pipe which supplied 5 special made heaters in a loop. When I look at the new heaters in various stores they are usually 3/4" max. I am apprehensive about replacing or adding heaters into the system that will reduce the flow.
Just my thoughts on the subject, dont know if it will apply to your system. |
Mad-Mel 4106-1090 (148.78.245.22)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 18, 2003 - 10:35 am: | |
Fast Fred, How are you using the rug? As a rug near the door or over the huge dash? I'm making a run next week with my grandkids from Africa. It's 106 in their home town and 33 in Boise. I want all the cheap temperature protection I can add in a hurry.
Thanks
Mel 4106 (Not Mel 4104) |
FAST FRED (209.26.115.105)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 18, 2003 - 1:09 pm: | |
Mel the simplest is to use a thin rope and hang a curtan to seal off the front of the coach.
Pretty hard to heat a designed leaky door and the big windsheilds, so drape a sheet or blanket back as far as you need to to stay away from the front.
Some folks with only one rooftop Air seal most of the REAR of the coach while driving with the genset on firing the rooftop.Just the front stays cool
The bathroom carpet goes on the floor.
FAST FRED |
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