Abandon my in-floor heat?

[ShawnJ]

I live on the east coast of Canada and I purchased a home a few years back that has a 24 x 40 attached garage with in-floor heat. It's running a small oil fired boiler. After a few years of paying wayyy to much in oil (thousand+ / season) just to keep the garage above freezing; I've had it. I think that the slab was probably not insulated properly or at all.

I'm thinking about switching to a hydronic garage heater like the Modine HC-47 http://www.h-mac.com/modine-hc47.html
Would this be any more economical than my current set-up?

Any ideas would be appreciated...

 

[philjafo]

Maybe change the heat source.

http://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/

 

[rsanter]

Look on the net for something called ' the half project'
The guy was working on cutting his utility bills in half
Basically he built a green house type thing on the side of his shed and used it tallest the suns heat in the pipes in it and a small pump to cycle that water through the tubes he had in his floor. And yes it works even when there is snow out

Bob

 

[theoldwizard1]

Look on the net for something called ' the half project'
The guy was working on cutting his utility bills in half
Basically he built a green house type thing on the side of his shed and used it tallest the suns heat in the pipes in it and a small pump to cycle that water through the tubes he had in his floor. And yes it works even when there is snow out

East coat of Canada !

I'll bet temps hit -20F often !

 

[theoldwizard1]

I think that the slab was probably not insulated properly or at all.

How about the walls and ceiling ? How many windows ? Are the double or triple glazed ?

Radiant heat does not handle large temperature changes well, like open a large door. If the ceiling is high, fans do help.

 

[tatra]

maybe consider applying 4x8 sheets of styrofoam along the perimeter of the building ......know of one build where they did this and made a huge difference........also how often was your pumpcycling and what kind of zones do you have........having worked on heated concrete in canadian winters i would suggest you find a away to make it work......

 

[ShawnJ]

Thanks for the reply Bob. I'll definitely check it out.

Shawn

 

[ShawnJ]

@theoldwizard - walls and ceiling are well insulated. I have double glaze windows, 4 of them. I also have a skylight.. which probably doesn't help.

@tatra - I'll keep the foam board in mind. I didn't monitor it well, but the pump seemed to cycle way too often. There are 5 valves on the boiler, so I guess 5 zones... all of which were un-marked when I bought the house. I wish I had a thermal camera so I could see what was what...

Has anyone here used the ceiling mount hydronic heaters before that I mentioned above?

 

[ShawnJ]

@philjafo - I don't have the funds to change the heat source unfortunately.

 

[HoosierBuddy]

I live on the east coast of Canada and I purchased a home a few years back that has a 24 x 40 attached garage with in-floor heat. It's running a small oil fired boiler. After a few years of paying wayyy to much in oil (thousand+ / season) just to keep the garage above freezing; I've had it. I think that the slab was probably not insulated properly or at all.

I'm thinking about switching to a hydronic garage heater like the Modine HC-47 http://www.h-mac.com/modine-hc47.html
Would this be any more economical than my current set-up?

Any ideas would be appreciated...

Do you really have to heat it? If not don't. That will save 100%.

If you do have to heat it...but can get away with heating it only when you are out there, not 100% of the time, adopt a strategy to do that. That will likely mean a new heating system, but could easily save you 80%.

Phil

 

[ShawnJ]

Do you really have to heat it? If not don't. That will save 100%.

If you do have to heat it...but can get away with heating it only when you are out there, not 100% of the time, adopt a strategy to do that. That will likely mean a new heating system, but could easily save you 80%.

Phil

I'm not in the garage very much now so I don't need to keep it heated all of the time. That's why I was wondering about the modine ceiling mount hydronic heater. That way I could use still my existing boiler and just use the heater on demand.

I'll think I'll call a local heating company to come and give me a quote on installation.

 

[CARS]

I feel like I was mentioned in a couple responses

I had a "know it all" plumber install my infloor system (he made many mistakes). While I insulated under the floor, my stem walls were exposed so I lost a ton of heat to the outside world. I dug down a couple feet along the outside and added 2" foam board to the wall. Helped tremendously.

That was the addition to my "old" shop.

To handle heating the old shop I hooked up a hydronic hanging unit to the boiler (different thermostat and pump). Works great.

I also added a couple cast-iron radiators to the boiler for the office and restroom. They are on a separate thermostat and pump too.

So to try and explain this better, I have a LP boiler. From there I have 3 circulating pumps. One for the in-floor that goes to a tempering valve (mixing valve) to allow 90 degree (f) water to go to the slab, one for the radiators, and one for the hanging unit. The 3 thermostats go to a Taco 3 zone relay to turn on each pump and the boiler. I believe the high limit on my boiler is set at 180 degrees.

It's kind of a mess by industry standards, but it all works well.

 

[CARS]

Did you see this: http://www.garagejournal.com/forum/showthread.php?t=196751

Inexpensive but might cost some coin to ship.

 

[MScott]

There is a member on here named Walrus who lives in Maine and has solar powered infloor heat. His build thread is at: http://www.garagejournal.com/forum/s...started+walrus

 

[Shop Specialties]

Is the in-floor the issue or the cost of the fuel ?

The in-floor could be doing its job properly but you are not happy with paying for the fuel which are 2 totally different things.

 

[Rickcnc]

There is a member on here named Walrus who lives in Maine and has solar powered infloor heat. His build thread is at: http://www.garagejournal.com/forum/s...ad.php?t=40482

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http://www.garagejournal.com/forum/showthread.php?t=40482&highlight=started+walrus

 

[ShawnJ]

Is the in-floor the issue or the cost of the fuel ?

The in-floor could be doing its job properly but you are not happy with paying for the fuel which are 2 totally different things.

I "think" the in-floor is the issue. My first year it cost about 420 / month in the winter and I was running it at around 20C (68F). I hope this isn't normal. I now leave the temp at 16C (60F) and I think I spent about 250 / month on oil.

 

[ShawnJ]

I feel like I was mentioned in a couple responses

I had a "know it all" plumber install my infloor system (he made many mistakes). While I insulated under the floor, my stem walls were exposed so I lost a ton of heat to the outside world. I dug down a couple feet along the outside and added 2" foam board to the wall. Helped tremendously.

That was the addition to my "old" shop.

To handle heating the old shop I hooked up a hydronic hanging unit to the boiler (different thermostat and pump). Works great.

I also added a couple cast-iron radiators to the boiler for the office and restroom. They are on a separate thermostat and pump too.

So to try and explain this better, I have a LP boiler. From there I have 3 circulating pumps. One for the in-floor that goes to a tempering valve (mixing valve) to allow 90 degree (f) water to go to the slab, one for the radiators, and one for the hanging unit. The 3 thermostats go to a Taco 3 zone relay to turn on each pump and the boiler. I believe the high limit on my boiler is set at 180 degrees.

It's kind of a mess by industry standards, but it all works well.

Thanks for sharing your setup I think that I will try something very similar. And thanks for the link to the used Modine units. I think shipping would be a killer though.

 

[Shop Specialties]

What are your outside temps and what are paying per gallon ?

 

[CARS]

Before you just abandon it, I would hire a pro to look at it and diagnose the system you have. Things like supply and return temps (mine is under 10 degrees Fahrenheit differential), flow, etc.

Know someone on the Fire Dept. that would do some "training" on the use of an Imagining Camera? I am on our F.D. so I just took it out one night during drill and could see the heat escaping, so that is why the next summer I dug it out and insulated it. I wonder if a radiant Pro wouldn't have the same technology

Good Luck!

 

[ShawnJ]

Before you just abandon it, I would hire a pro to look at it and diagnose the system you have. Things like supply and return temps (mine is under 10 degrees Fahrenheit differential), flow, etc.

Know someone on the Fire Dept. that would do some "training" on the use of an Imagining Camera? I am on our F.D. so I just took it out one night during drill and could see the heat escaping, so that is why the next summer I dug it out and insulated it. I wonder if a radiant Pro wouldn't have the same technology

Good Luck!

I actually do have a few friends in the F.D. That's a great idea!

 

[BadgerBoilerMN]

How about the walls and ceiling ? How many windows ? Are the double or triple glazed ?

Radiant heat does not handle large temperature changes well, like open a large door. If the ceiling is high, fans do help.

Actually the inherent energy stored in a radiant slab is the best emitter for large spaces and recovers comfort, as apposed to air temperature, much faster than any scorched-air unit could.


http://www.cement.org/tech/pdfs/PL971Radiant.pdf

I would look to the perimeter of the slab. Even if the field is not insulated keeping shop above freezing should not take much if the frost line it dealt with in an efficient manner.

That is, dig down around the outside of the foundation and insulate with 2" of XPS minimum.

 

[Larosa]

why dont you look for heat sensors that are used one . this would sort out the problem of yours and would also save your money a lot

 

[gte718p]

Another option is to drop the temp to 45 degrees or so just to keep things from freezing. The use a small portable heater for local heat in the vicinity of were you are working.

 

[CARS]

why dont you look for heat sensors that are used one . this would sort out the problem of yours and would also save your money a lot

 

[ShawnJ]

why dont you look for heat sensors that are used one . this would sort out the problem of yours and would also save your money a lot

Sorry. I don't understand.

 

[Randy in Maine]

I am down here at the beach south of Portland. Similar to Halifax, but maybe a tad warmer.

68º F is pretty warm. I keep the house at about 67º and it is pretty comfy. Any warmer and I sweat all night. The floors in the house are about 6-8º warmer than the house air. When my wife is cold, she turns on our fake woodstove (that runs on propane) and it gets the air pretty toasty after about 20 minutes in the house, then it goes off.

I keep my 40' x28' x12' garage/woodshop at 55º F or about 14ºC (using a wall mounted thermostat) which is pretty nice for me all winter. The floor is about 62º. I am good with a long sleeve shirt out there without overheating when working or getting too cold when I am just dinking around.

I am pretty well insulated in the house and the garage, little infiltration, and use a condensing Baxi boiler (3 zones) that runs both the 1200 square foot house and 1200 square foot garage. I heat the whole set up for about $1500 US per year on propane (600 gallons at $2.49). This year I actually used about 480 gallons and it was a cold winter. I turn it on at the end of November and turn it off about mid April.

I send hot water out there about 120º and it comes back about 90º, so I am only adding about 30º to it.

 

[BadgerBoilerMN]

This is a good description of a typical, simple radiant floor heating with LP condensing boiler system. The inclusion of operating cost and inside design temperature brings it all together.

Thank you.

 

[ShawnJ]

I am down here at the beach south of Portland. Similar to Halifax, but maybe a tad warmer.

68º F is pretty warm. I keep the house at about 67º and it is pretty comfy. Any warmer and I sweat all night. The floors in the house are about 6-8º warmer than the house air. When my wife is cold, she turns on our fake woodstove (that runs on propane) and it gets the air pretty toasty after about 20 minutes in the house, then it goes off.

I keep my 40' x28' x12' garage/woodshop at 55º F or about 14ºC (using a wall mounted thermostat) which is pretty nice for me all winter. The floor is about 62º. I am good with a long sleeve shirt out there without overheating when working or getting too cold when I am just dinking around.

I am pretty well insulated in the house and the garage, little infiltration, and use a condensing Baxi boiler (3 zones) that runs both the 1200 square foot house and 1200 square foot garage. I heat the whole set up for about $1500 US per year on propane (600 gallons at $2.49). This year I actually used about 480 gallons and it was a cold winter. I turn it on at the end of November and turn it off about mid April.

I send hot water out there about 120º and it comes back about 90º, so I am only adding about 30º to it.

Thanks for your information on your set up and use. I appreciate it.

It seems that I'm probably losing quite a bit of heat through the stem wall as someone mentioned earlier; I'm going to attach some rigid foam before fall. I've also found that my shared wall between the house and the garage was NOT insulated! I just had the wall filled with blown in cellulose, so hopefully that will help in keeping the house side warmer. Now I should be able to keep the garage cooler without affecting the rest of the house.

Thanks everyone for your helpful advice.

 

[Chilliwack Murray]

I'm on the other (warmer) coast of Canada... I am planning to put the tubing in the slab on my upcoming project but as an experiment I am going to run a length of tube, say 100 150' in a 4-5' deep trench and circulate that through the slab. The shop will be insulated so I am hoping this will keep it from freezing in the shop for very little (no) cost but I haven't seen any examples of this done. I have not done any calculation of the amount of heat you get from the ground but like I said, I just want a simple system to keep it from freezing without my having to intervene. I will heat it with wood when I am working in it. It will be an experiment. Oh yeah, did I mention I'm Dutch?

 

[CARS]

I'm on the other (warmer) coast of Canada... I am planning to put the tubing in the slab on my upcoming project but as an experiment I am going to run a length of tube, say 100 150' in a 4-5' deep trench and circulate that through the slab. The shop will be insulated so I am hoping this will keep it from freezing in the shop for very little (no) cost but I haven't seen any examples of this done. I have not done any calculation of the amount of heat you get from the ground but like I said, I just want a simple system to keep it from freezing without my having to intervene. I will heat it with wood when I am working in it. It will be an experiment. Oh yeah, did I mention I'm Dutch?

Ground source geothermal?

 

[ShawnJ]

I'm on the other (warmer) coast of Canada... I am planning to put the tubing in the slab on my upcoming project but as an experiment I am going to run a length of tube, say 100 150' in a 4-5' deep trench and circulate that through the slab. The shop will be insulated so I am hoping this will keep it from freezing in the shop for very little (no) cost but I haven't seen any examples of this done. I have not done any calculation of the amount of heat you get from the ground but like I said, I just want a simple system to keep it from freezing without my having to intervene. I will heat it with wood when I am working in it. It will be an experiment. Oh yeah, did I mention I'm Dutch?

I'm interested to hear how your ground source heating project works out.

 

[sickjuice]

I'm on the other (warmer) coast of Canada... I am planning to put the tubing in the slab on my upcoming project but as an experiment I am going to run a length of tube, say 100 150' in a 4-5' deep trench and circulate that through the slab. The shop will be insulated so I am hoping this will keep it from freezing in the shop for very little (no) cost but I haven't seen any examples of this done. I have not done any calculation of the amount of heat you get from the ground but like I said, I just want a simple system to keep it from freezing without my having to intervene. I will heat it with wood when I am working in it. It will be an experiment. Oh yeah, did I mention I'm Dutch?

Thats not an experiment thats called a horizontal loop geothermal system. You don't have to guess, a geothermal engineer could spec the loop size, depth, ect to heat properly the building.

As for running the system at "little (no)" cost do you think that pump is going to run constantly for free?

If natural gas prices are similar in BC as to what they are in Manitoba the reason you haven't seen anyone do it is because natural gas is cheaper heat than geothermal

 

[Chilliwack Murray]

Thats not an experiment thats called a horizontal loop geothermal system. You don't have to guess, a geothermal engineer could spec the loop size, depth, ect to heat properly the building.

As for running the system at "little (no)" cost do you think that pump is going to run constantly for free?

If natural gas prices are similar in BC as to what they are in Manitoba the reason you haven't seen anyone do it is because natural gas is cheaper heat than geothermal

Since my goal is to keep it from freezing in the shop, I'm not planning on a heat pump at this point, just circulating some water / glycol in the system with hot water heating pumps, so not entirely free to operate, it would be nearly free compared to a heat pump compressor or anything else I could think of. When I want it warm I will supplement with wood heat and the finished area will be heated with electric heat initially. Just something I would like to try. Basically I would only have the cost of the horizontal run outside and some sweat to get it in the ground. The remainder of the system can used for any heat source I choose, and if I'm smart, I would make sure the ground loop is compatible as well. Often the reason 'no one else is doing it' is because the professionals said it would never work. Remember, they work in the day to day application of existing products with a quick turn around in order to make money - if they don't make money, they don't stay in business. You won't find an HVAC contractor that would consider installing anything that would be an experiment not just for financial reasons but code reasons as well. CM.

 

[rancherbill]

Would this be any more economical than my current set-up?

Maybe, but, you have to do some research as to where you are losing your heart. It's a long list of things to check.

I know nothing about your systems but where I'd look first was on the controls for the furnace - how the controller is set. Some plumbers know nothing about the control side.