The Wall
Forum / THE MAIN WALL / Modine HW Unit in Garage
  • Post a Reply to this Thread

    Modine HW Unit in Garage (26 Posts)

  • Sidponcho Sidponcho @ 5:15 AM
    Contact this user

    Modine HW Unit in Garage

    Hi All
    I have an attached 2 car garage (New England) and just hung a new Modine HW unit from the joists.  The plan is to pipe this to my exisitng boiler in my basement amd add a zone.  For safety reasons, I chose the hot water unit over any type of gas, oil or electric heaters. 
    Here's where my crazy idea comes in.  Days or even weeks will go by when I am not out there working.  What I'd really like to do is put drains in the unfisished basement side so that the garage unit and piping can be drained when not in use.  Am I nuts?
    Thanks
    Dan
  • Eric Eric @ 5:49 AM
    Contact this user

    ummmm...

    I feel a set up like that is going to end in one of two scenarios:

    The zone stays off most of the time, even if you'd like to use it , just too much work to hang in the garage for an hour or two.

    OR

    The zone freezes and splits a line cause it gets left on.

    How cold does the garage get? ever put water out there and see what happens thru the years?

    You might be better off adding glycol to the system and not worry about it.
    This post was edited by an admin on February 7, 2014 5:49 AM.
  • M Lane M Lane @ 6:51 AM
    Contact this user

    Glycol

    Then no need to drain. Go with at least 40% though. We use 50% for outside systems like snowmelt.
  • icesailor icesailor @ 10:45 AM
    Contact this user

    Modine Heater in Garage:

    FWIW,
    My home on Cape Cod (Brewster) was built new in 2000. Typical Cape with attached 2 car garage, 24' X 24'. Heated office space above. 12"+ insulation in ceiling. Firecode sheetrock. No insulation in 2" X 4" walls. 3- Anderson Perma-shield  double hung, insulated glass. Two metal garage doors. No heat in garage.
    In 13 years, I never EVER had anything freeze in the garage. I had latex paint, water, and any number of things that could have broken. They didn't.
    If you keep the doors closed, and anything that you are afraid might break from freezing, keep it on a wall that borders the house. On the coldest days of the winter, I could put my iceboat on the trailer into the garage when I came home from sailing. There could be ice and snow on the boat and trailer when I put it away when I came home. The next morning, all the ice and snow would be melted and wet on the floor.
    If you put in a Modine, it should be installed in such a way that it can be isolated and on its own zone. You should be able to easily drain it if needed.
    Install a bomb proof El Cheapo thermostat and set it as low as you can get. Like 40 degrees F. It won't hardly ever come on. You can put the fan on a switch or a cold temperature thermostat and switch it off when you don't need it. If the unit is mounted against a inside wall and up high, it will never get cold enough to freeze.
    Avoid using Anti-Freeze at any cost if you can. Insulate the pipes.

    IMO and experience.  
  • jumper jumper @ 4:36 PM
    Contact this user

    forget the zoning

    Control the fan with a thermostat. How much heat does a unit heater lose with fan off?
    Draining & re filling have negatives.
  • EBEBRATT-Ed EBEBRATT-Ed @ 6:45 PM
    Contact this user

    Brazed plate

    Brazed plate hx is pretty cheap. Glycol it and a small expansion tank. Then you don't have to worry. you want to be able to go on vacation and not worry about it.
  • Wethead7 Wethead7 @ 9:13 PM
    Contact this user

    Hot Water unit heater

    I would put antifreeze in the entire system. You would only need about 10% . It may turn into a slush but not hard freeze any longer. You might need some upgrades to the system. Back flow prevention, or a pressure switch. The annual service should include the testing and treatment of the closed loop fluid.
  • Sidponcho Sidponcho @ 6:45 AM
    Contact this user

    Thanks

    Thanks for the replies so far.  Here's a couple of pics of what I have so far.  The boiler is all new.  I wanted to avoid glycol but it may be best
  • Bob Bona Bob Bona @ 8:24 AM
    Contact this user

    do not destroy this beautiful system with antifreeze

    You add antifreeze to this and you've begun a lifetime of upkeep and attention. Heat transfer will be reduced. Pumps will work harder to do the same work. Any leak will be a maintenence headache. You will see corrosion forming at seals. Add another zone for the modine and install a flat plate heat exchanger to isolate it from the rest of the system. Glycol only the modine side.
  • Bob Bona Bob Bona @ 8:29 AM
    Contact this user

    do not destroy this beautiful system with antifreeze

    You add antifreeze to this and you've begun a lifetime of upkeep and attention. Heat transfer will be reduced. Pumps will work harder to do the same work. Any leak will be a maintenence headache. You will see corrosion forming at seals. Add another zone for the modine and install a flat plate heat exchanger to isolate it from the rest of the system. Glycol only the modine side.
  • Bob Bona Bob Bona @ 8:29 AM
    Contact this user

    do not destroy this beautiful system with antifreeze

    You add antifreeze to this and you've begun a lifetime of upkeep and attention. Heat transfer will be reduced. Pumps will work harder to do the same work. Any leak will be a maintenence headache. You will see corrosion forming at seals. Add another zone for the modine and install a flat plate heat exchanger to isolate it from the rest of the system. Glycol only the modine side.
  • delta T delta T @ 11:25 AM
    Contact this user

    Bob and Ed are right

    the least amount of headache, maintenance, and worry will be the plate exchanger. Unless there are problems with pipes freezing on the house side of the system I would NEVER put glycol in this system. much more wear and tear, not to mention more maintenance and more energy consumption.
  • delta T delta T @ 11:25 AM
    Contact this user

    Bob and Ed are right

    the least amount of headache, maintenance, and worry will be the plate exchanger. Unless there are problems with pipes freezing on the house side of the system I would NEVER put glycol in this system. much more wear and tear, not to mention more maintenance and more energy consumption.
  • icesailor icesailor @ 12:16 AM
    Contact this user

    Do what you want:

    Do what you want and spend what you will.

    Its 17 degrees on Cape Cod right now. I have never seen ice on the floor of my 2 car garage that the doors face the North-West. Just water in the floor from the ice melting from under the car. Mount the Modine up high against the heated part of the house and be done with it. Insulate the pipes.
    If you put Anti-Freeze in your heating system and it doesn't need it, you or someone will be extremely sorry. There isn't anything good about it. Even when you think that you will need it.
    I've been in my garage when it was 5 degrees out and the ice melted on the concrete floor by the garage doors. They faced the North.
  • M Lane M Lane @ 12:02 PM
    Contact this user

    Here in the Rocky Mountains,

    We glycol every system. This provides protection for absentee property owners. One thing glycol does is balance the ph of a system to where calcification is eliminated, which is a huge benefit. B/C of the smaller molecules, you might develop leaks that were not present before with water only, but they are pinholes. You might have to check your pump curves again, but I have found that usually the original pump makes the curve with glycol too.
  • Gordy Gordy @ 12:25 PM
    Contact this user

    Glycol decision

    Glycol has its place, but in this case I would not.
  • Sidponcho Sidponcho @ 2:25 PM
    Contact this user

    good option

    Thanks all.
    I like the idea of the plate exchanger! I assume it would install on the basement side? How do I know which one to get? I was hoping to add this zone DIY but it looks like I might have to get someone in here.
  • Bob Bona Bob Bona @ 7:00 PM
    Contact this user

    HX would

    Go in basement. Flat Plate Inc (how convienent) has a chart to size the item. Or call them for technical recommendations. Straight water on boiler side.
  • Wethead7 Wethead7 @ 3:02 PM
    Contact this user

    Heat exchanger

    I like the Idea, but the boiler water side can freeze. The unit heater closed loop side can get below freezing and solid the boiler water side. I have seen this happen. This is the reason I recommended antifreeze. The running the pump constantly and cycling the fan would work. The only issue would be the loss of electrical power.

    My home has 14% glycol. I was trying for 10% , but added to much. I have a snow melt system. I have froze and broke the heat exchanger. The outdoor side is charged with 55% glycol. The system did a start after very low temperatures. ( -10) The snow came with a warm up. The glycol has not been an issue. The annual service and adjustment is all that is required. I have lost a flow switch on the boiler, but nothing major. I think the switch was most likely bad in the first place. If you are not in the trade, your boiler should be serviced annually. They should preform this on the same visit. I am not so sure about running more than 20% on the boiler side. It could be done, but if you live in the home. You would be dealing with it before it became that cold.
  • SWEI SWEI @ 4:32 PM
    Contact this user

    None of us would ever recommend

    running straight water in a snowmelt system.

    Many of us would recommend running straight water in his application, given the conditions clearly expressed above.
  • Gordy Gordy @ 7:13 PM
    Contact this user

    Care should be given

    Of course as to not forgetting to close garage door for the whole day in extreme conditions. Limiting supply return piping projection to, and from the unit helps. Mount unit on shared house garage wall.
  • Sidponcho Sidponcho @ 8:44 PM
    Contact this user

    ideas

    The unit is hung on the house wall. Pipes will run 1' horizontal then 7' down the wall and then over the sill.
    What if I add a simple water zone for the unit, keep it 50f in the garage all the time. AND run the circulator 5 minutes every hour (I program PLC's).??
  • Bob Bona Bob Bona @ 9:04 PM
    Contact this user

    even better

    Thats actually what i would do. Forget the glycol entirely. Insulate the pipes, cycle the pump. You'd want to gussy up the control logic..typically the t stat calls, starts the pump/burner and a high volt aquastat at the modine brings on the fan at the setpoint temp of the aquastat.

    this is no different than a hydro air setup with a freezestat. You will want the pump to respond on low temp but not initiate fan from a pipe temp rise. Do able.

    of course if you lose power....thats a different story but they make generators.
    This post was edited by an admin on February 8, 2014 9:07 PM.
  • Sidponcho Sidponcho @ 7:29 AM
    Contact this user

    pipe size

    what size pipe should I run to the new unit?  The Modine has 1-1/4 npt femail ports.
    Should I get black iron reducers then go down to copper?
  • Bob Bona Bob Bona @ 10:09 AM
    Contact this user

    assuming

    It's the 40k btu unit which most res garages use, 3/4 piping is fine. Bush down.
  • icesailor icesailor @ 11:14 AM
    Contact this user

    Its colder in Colorado:

    You said that you live in New England. Unless you are living in the Northeast Kingdom of Vermont, The lakes Region and above in New Hampshire or Washington County down Maine way, it isn't as cold where you probably live.
    Even in Florida where it is warm, the number of garage doors left open 24 hours a day can be counted on the toes of my son's left foot. (My son only has 4 toes on his left foot).
    Building heat loss is figured on "conditioned space" and unconditioned spaces like garages are considered outdoors because you can leave the doors open 24/7.
    Experience shows that most people don't leave their garage doors open 24 hours a day because they don't want criminal eyes to get a peek inside. If the doors are kept closed except for those brief periods to go in or out, the space could be considered at 1/2 the temperature of the inside conditioned space to the outside space. 
    Most of us who have always done our own heat loss calculations know that the garage space can be I/2 and the outside walls that face these spaces, the loss numbers can be cut in half, but we have been taught to consider the garage space as an outside space. Even though it isn't.
    That's why garages are warmer than the outside if they are covered by a heated/conditioned space. If you want to use the garage as a work space, I would hope that you would want to have finishes (sheetrock) walls and a ceiling. Otherwise, you will just be heating the outside.
    The number 1 cause of excessive heat loss in most of New England in the winter is wind infiltration.
    I have never seen a garage in the winter with the doors and windows closed, have wind blowing through it. If you leave the doors open all the time, maybe you WILL have a problem. Get automatic door closers. At the push of a button, PRESTO, the doors open and close. Your wife will love you if she doesn't have to track snow into her car getting the door open. Maybe 20 days or nights a year where you seriously would have to worry about the space getting cold if you  left the doors open?
    I loved my unheated, non freezing garage in the winter cold. At night after work, I had a couple of 500 watt quartz lights and my normal work clothes and I was loving life. Working on my tractors and lawn mowers.
    They have green house industrial thermostats that go below 32 degrees. If you want to spend a lot of excess cash on something you are afraid will happen (and I don't think it will), go for it.
    Me, I'm eyeing a new power tool that I've been obsessing over that I could use. Like if I was still up North, a new composite mast for my iceboat and a sail to go with it. So I can enjoy those really cold and windy days where there was enough ice for a really speedy run on the ice.
  •  
Post a Reply to this Thread