Yet another hydronic heat question?

[somewhereinusa]

Originally Posted by pepepito

Any GPM minimum ?

There probably is but I doubt that it is very much. A pump like that will be good.

[pepepito]

Originally Posted by somewhereinusa

There probably is but I doubt that it is very much. A pump like that will be good.

and I will guess you can put them in series ?...maybe a bad idea

[pepepito]

So I end up winning a Bid on ebay for an Espar Hydronic 10 for like $362 USD and is the boxed version with the timer/thermostat, relays etc now the fun begins.

Somewhereinusa I see that you installed the circulation pumps right close to the manifolds is there a reason for that , how that have been working for you ?

Now I need to source, Water tanks, two heat exchangers and the PEX.

Thanks

[somewhereinusa]

So I end up winning a Bid on ebay for an Espar Hydronic 10 for like $362 USD and is the boxed version with the timer/thermostat, relays etc now the fun begins.

That's a really good deal

Somewhereinusa I see that you installed the circulation pumps right close to the manifolds is there a reason for that , how that have been working for you ?

I put them there because I had room there, those pumps push better than bull but it probably doesn't make all that much difference.

Now I need to source, Water tanks, two heat exchangers and the PEX.

I bought most of my pex from these guys, make sure you get the oxygen barrier tubing. I bought 1000 feet but ended up selling about 600 you won't need all that much for your shorty.

PEX Supplies for Plumbing and Heating - PexUniverse.com

When you buy your heating antifreeze make sure you get the kind that is made to be used in systems that have aluminum.

Dick

[pepepito]

what heat exchangers did you use ? I'm mostly worry about the heat exchanger for the fresh water tank but I guess if I look on using engine heat to heat the floor while running I will get the same type of heat exchanger to avoid coolant contamination....

I'm kinda worry about contamination but I have no idea how often a heat exchanger will leak internally ?

[somewhereinusa]

I used one of these for hot water it has a built in heat exchanger. I got a used one for no where near that price. It already has a pressure relief valve which you need since engine and Espar hot water gets hotter than regular domestic hot water. If you have youngsters you may also want some sort of mixing valve to keep your hot water from getting too hot.

Whale Seaward Water Heater 6 Gallon - Star Marine Depot

For the engine heat I used something like this.

5"x12" Brazed 40 Plate Heat Exchanger Outdoor Wood Furnace [1" MPT] | eBay

Price on that has come down quite a bit.

[pepepito]

Originally Posted by somewhereinusa

I used one of these for hot water it has a built in heat exchanger. I got a used one for no where near that price. It already has a pressure relief valve which you need since engine and Espar hot water gets hotter than regular domestic hot water. If you have youngsters you may also want some sort of mixing valve to keep your hot water from getting too hot.

Whale Seaward Water Heater 6 Gallon - Star Marine Depot

I really like that water heater, I will get one of those.

Do you happen to have a diagram of you system where includes the manyfold connections ?

I'm wondering how to do the loops for each system, like one connection from the manifold to the heat exchangers and back, anotherone for the floor loop and back etc...I will do a diagram with that and share it.

[somewhereinusa]

Do you happen to have a diagram of you system where includes the manyfold connections ?

Here's a link to the diagram.


Heat 2

The three loops that have heat in the floor have thermostats that control the circulating pump for that loop. The loop that goes to the front heater has a switch on the dash for that pump.The small heaters that have blowers have thermal switches on them so the blower won't come on unless there is warm water so they won't blow cold air. In practice it has worked out so that when the thermostat turns off the pump, that loop cools enough to turn off the blower. I have found that unless it's below zero I don't really need any of the blowers once heat achieved. Even in below zero temps the boiler will cycle between high and low which tells me that things are sized about right.

Flat front buses are notoriously cold while driving, your feet are only about a foot from the cold and since the electrical panel is beside you there is no insulation there either. I added two heaters for the driver, one blowing at my feet, the other at my body. There is also a bit of in floor heat right in front of the drivers seat. I also made a more positive way to make the front access doors close. Using the engine as a heat source I have been quite toasty warm in cold weather.


Dick

[pepepito]

Ok, now is more clear to me, I was thinking about how loops should interconnect or not and things like that but I was overthinking.

What kind of thermostat you use ? are there some specific for hydronic heat ?

And in another note :

Do you have a protection circuit to stop heat from the Hydronic 10 or engine heat in case it goes too high ? or that is just a matter of shutting off the pump ?

I gues my worry here is about or the fluid comming from the Esparr being to hot for the engine or the other way around......

[somewhereinusa]

I used the cheapest thermostats I could find and relays. Get a stat that has a definate "off" position.

The Espar high temp is 185 the engine is roughly 200. Not enough difference to matter.

[pepepito]

I just realized that the hydronic 10 I bought is 24v is yours too ?

I might need to add a step up transformer....

[somewhereinusa]

Yes, that's what I did. I've got kind of mixed setup but it works fine.

[pepepito]

Hi Dick.


In here :

somewhereinusa floor heat

I can see the aluminium plates right against the bus floor, then pink foam in between and the wooden blocks for the bends, I was wondering what did you use on top of that ?

more plywood and insulation and what size ?

Is long weekend here in Canada and I bought the pex and I was going to run the tubing but homedepot didn't have the aluminium plates and they had only 1 1/2" pink insulation and if I use that I will loose too much head room so it made me wonder.

Thanks.

[somewhereinusa]

I need to change that picture, that was a early method that I abandoned. In the final version I used 2 insulation and routed everything including the end loops. My floor is 3/4 plywood laid directly on top of that, basically a floating floor. The plywood is really nice, it has plastic bonded to both sides that I picked up in a rv surplus store.
I don't see why 1 1/2 wouldn't work, I've never seen it in the states. The aluminum plates are important and you don't want any kind of insulation between them and the flooring.

In the picture here Heat
The one labeled kitchen/living room shows the layout the picture on the right shows with floor installed. Those plates with the black on them are aluminum plates with gorilla tape on the edges to protect the pex from maybe a sharp edge. I used the plates to keep things in place, they are screwed through the insulation into the wood floor beneath.
I had a heck of a time getting the air out until I added bleed valves all the way up front,

[pepepito]

Ok, I'm going to do the same I think, that way I will not loose much head room and I can still put a 3/4" plywood on it, I just need to buy the aluminium plates that hopefully I can get tomorrow.

[pepepito]

I was doing my diagram and I was looking at yours and now I wonder : did you run the engine loop outside of the bus or you routed some pex going to the engine heat exchanger trough the inside of the bus ?

[Robin97396]

You guys have no idea how much us guys with cold feet are following your hydronic heating.

[pepepito]

More and more planing....my head is about to explode!!!

Since I didn't have my floor plan figure out completely I had to go under the bus to figure out where I'm going to install everything else like water tanks, battery storage, inverts, grey water, water heater, sink, bed and all that to be able to figure out where I will route the PEX without having much of a problem with having to drill a hole for the drains an such so I create a very rough plan of how I will route the PEX.

Keep in mind this is a 22 foot bus so space is limited and need to be optimized fully. I can switch the hydronic from one side to the other but since the fuel line is on the left side I though it was going to be easier and I haven't think yet on how I will fill up the system or anything like that so I need to leave space just in case.

here is the diagram :

[IMG]More and more planing....my head is about to explode!!!

Since I didn't have my floor plan figure out completely I had to go under the bus to figure out where I'm going to install everything else like water tanks, battery storage, inverts, grey water, water heater, sink, bed and all that to be able to figure out where I will route the PEX without having much of a problem with having to drill a hole for the drains an such so I create a very rough plan of how I will route the PEX.

Keep in mind this is a 22 foot bus so space is limited and need to be optimized fully. I can switch the hydronic from one side to the other but since the fuel line is on the left side I though it was going to be easier and I haven't think yet on how I will fill up the system or anything like that so I need to leave space just in case.

Any concerns, Ideas ?


here is the diagram :

[somewhereinusa]

did you run the engine loop outside of the bus or you routed some pex going to the engine heat exchanger trough the inside of the bus

My heat exchanger is in the engine compartment. I have a rear engine, I mounted the exchanger right on the firewall where the auxiliary heater pump was.

I don't see anything wrong with your proposed layout. The pex specs say that minimum radius is 4" for 1/2" pex. I found I could cheat a little and used, I think about 3 1/2" If you are going to use engine heat while you are driving I would suggest going around driver seat so that you have at least one tube in driver foot area. I also have 1 small heater blowing on my feet. I also disconnected the original heater core and put it on the hydronic heat system. That gives you a bit of forced air heat while parked and running boiler. I changed the original water connections to pex by using JB Weld to put Pex fittings on. I would probably just find some pex barb fittings and use heater hose if I had to do it again. I would also suggest eliminating that extra loop under the bed and put a small forced air heater in the rear. I have 6 of them and, while not absolutely necessary it helps with quick warm up from dead cold. I can get it up to about 70° from below 0 in about an hour. I then turn off all of the blowers. The blowers have temp switches so that they won't come on when the water is cool so they will never blow cold air.
I bought my small space heaters, got a really good deal but, you can make your own using a car heater core and 12v muffin fans.

[pepepito]

And again Thanks for all the info.

After looking a million times more my bus underneath and the diagram, I will be making a new diagram soon since I forgot many things and I want to deal with fresh water at the same time so I can figure where to put all the manifolds and things....I will be doing a big order in pex universe

When running the hydronic 10 how long takes for you to heat up the fresh water ?( when not connected to shore power)


I will keep you posted.