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High Propane Usage - Hydronic Radiant Heat


dtontarski
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I wasn't sure which forum to post this in -

I just received an inquiry to inspect an efficiently built 1996 foreclosed on home. The buyers concerns are that the home wasn't properly winterized and this is complicated by the fact that it has an in-floor hydronic radiant system. The interesting bit of information they provided was that the home used 3,000 gallons of propane the year before it was abandoned. I don't know much about propane consumption, but this seem excessive for a less than 3,000 square foot home that is built efficiently even in upstate New York. (isn't that about 10K worth of propane?)

Anyone have any ideas, other than a fairly considerable gas leak on how this home would consume this much propane - maybe someother hydronic/hyponic activity going on?

This one has me a bit nervous...any words of wisdom on inspecting this home? Anyone have any bad experiences with hydronic radiant systems that were not properly winterized or just otherwise failed....how best to inspect, etc...?

Any thoughts on this would be appreciated. It's about a 150 mile round trip and the only reason I'm considering this is that it takes me fairly close to a couple of fairly good trout streams.

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Tell the interested parties to hire a guy who has experience with propane/hydronic heat, and ask him what to do.

If you're curious about the 3K gallons of gone propane, call a propane supplier and ask if that's a high number for this house.

If you're down on the farm, and you want to stay warm: Propane...

WJ

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I wasn't sure which forum to post this in -

I just received an inquiry to inspect an efficiently built 1996 foreclosed on home. The buyers concerns are that the home wasn't properly winterized and this is complicated by the fact that it has an in-floor hydronic radiant system. The interesting bit of information they provided was that the home used 3,000 gallons of propane the year before it was abandoned. I don't know much about propane consumption, but this seem excessive for a less than 3,000 square foot home that is built efficiently even in upstate New York. (isn't that about 10K worth of propane?)

Anyone have any ideas, other than a fairly considerable gas leak on how this home would consume this much propane - maybe someother hydronic/hyponic activity going on?

This one has me a bit nervous...any words of wisdom on inspecting this home? Anyone have any bad experiences with hydronic radiant systems that were not properly winterized or just otherwise failed....how best to inspect, etc...?

Any thoughts on this would be appreciated. It's about a 150 mile round trip and the only reason I'm considering this is that it takes me fairly close to a couple of fairly good trout streams.

To do a simple test on the in floor system,

When you arrive mark or note the water pressure on the boiler and then turn up the thermostats for more heat.

Turn off the boiler water feed valve.

Do some other inspecting things like looking at the crappy tile or ugly paint.

When you finish the other inspector things check the boiler pressure. If it is significantly lower, (one or two lbs.) there is a leak in the system which would cause a high use of propane.

But the advice to call a local propane guy to find out the normal usage in your area is the first thing you should do.

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When you finish the other inspector things check the boiler pressure. If it is significantly lower, (one or two lbs.) there is a leak in the system which would cause a high use of propane.

Not sure I follow the logic about a leak causing an increase in propane use. By bringing in a large amount of makeup water the boiler fires more?

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Originally posted by John Ghent

Not sure I follow the logic about a leak causing an increase in propane use. By bringing in a large amount of makeup water the boiler fires more?

First boil a pot of pasta water and time it. Then boil a pot of water but keep taking some out and adding fresh cold water and time it. The answer is yes, a leak will cause the use of more fuel by causing the boiler to run longer. But this may not be the cause of a large amount of fuel use if it is a small leak so it is best to know what is common in the area.

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Thanks for the suggestions and explanations, and the prompt to play some old Clapton - and some new....Riding With The King is playing now.

The individual that inquired regarding this inspection was told by the utility company that 3,000 gallons of year was excessive. I thought that the amount was errantly reported to me intially and requested they double check this. I was surprised that no one monitoring the forum remarked on this amount. Could there be any explanation for consuming this much propane to heat a < 3,000 square foot home reported to R-48 of attic insualation and R-19 walls? I just can't imagine spending 9 grand a year on propane. (I was told that it is about $3.00/gallon but haven't confirmed this)

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Since my last post I have learned that propane currently averages about $2.50/gal in New York State. The propane supplier I spoke to stated that hydronic radiant flooring systems generally use more propane than force air systems, but still estimated that the home in question should be expected to use around 1,500 gallons a year. They had no explanation of what would result in twice the average consumption. I think I'm going to steer clear of this one.

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Gas consumption is dependent on a lot of things such as heat loss, degree days, number and size of appliances and lifestyle of the occupants etc.

This is what we use here in Calgary (5200 dd) to estimate propane fuel consumption. Remember that this is an approximation and can vary greatly.

2000sf home

Mid efficiency furnace - 3200 liters/yr or 850 gallons

Water heater - 1200 liters/yr or 320 gallons

Gas range - 350/yr liters or 92 gallons

If you say the house was vacant in the last year then we'd only be concerned with the furnace consumption or 850 gallons.

But we have a 3000sf home so that would put us at around 1300 gallons for a standard built home.

Since the home is energy efficient, what ever that means, you could discount the figure by whatever percentage. So yes, 3,000 gallons in one year would appear excessive.

With regard to your radiant in floor system:

"To do a simple test on the in floor system,

When you arrive mark or note the water pressure on the boiler and then turn up the thermostats for more heat.

Turn off the boiler water feed valve."

DO NOT turn off the water feed valve. Let me repeat myself

DO NOT turn off the water feed valve.

NEVER turn off the water feed valve..........EVER

If you should have a water leak in the system and the boiler is missing a low water cut out valve or one that is malfunctioning, you could risk damaging the boiler.

The system should have either glycol throughout the distribution tubing or an exchanger for zones that are susceptible to frost damage such as an attached garage. But from your information I would guess frost damage is not an issue considering the high fuel consumption unless of course the windows and doors were left open and resulted in frost damage somehow.

Good luck with your inspection.

RC

YourCalgaryHomeInspector.com

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Looks like you beat me to the punch.

I'm not sure why you'd pass on this one. I see this as a great learning opportunity. But then again I like a challenge.

"The propane supplier I spoke to stated that hydronic radiant flooring systems generally use more propane than force air systems"

You might want to ask him where he got his information.

RC

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Rob -

Thanks for your reply and your advice. April is traditionally the busiest month for me locally. I've driven 3 + hour round trips several times for inspections, but these were desireable properties. (historically, geographically, or otherwise compelling) This is a foreclosure that was not properly winterized and I don't have any guarantees that I will have electricity, propane or water. I too love a challenge, but this one has too many unknowns.

Dave

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Its good information to have. I would do the inspection to see if there were any obvious reasons. I've inspected "fairly efficient" houses where the builder forgot to put insulation in the attic. So it may be as simple as that. Be sure to mention it in your report and if there are no obvious reasons recommend further evaluation like a line test or a blower door test. Also, if there is radiant floor heat in a vacant unheated house, I would flag it until an Infrared evaluation confirmed that there were no leaks. This would be an excellent use of IR. If possible, have the agent or the bank turn up the heat the night before the inspection.

If there is a leak, you would probably smell it. Especially with the house being closed up.

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DO NOT turn off the water feed valve. Let me repeat myself

DO NOT turn off the water feed valve.

NEVER turn off the water feed valve..........EVER

If you should have a water leak in the system and the boiler is missing a low water cut out valve or one that is malfunctioning, you could risk damaging the boiler.

No one seems willing to do anything anymore. Of course you could ignore my test and call for further evaluation by a heating specialist.

Of course the boiler should have a LWC. But even if it did not, and there was a leak, it would have to be a massive leak to cause harm to the boiler. If it had a leak of any such magnitude it would be obvious as soon as the water feed was shut down. I found many such leaks over the years by doing what I described above. I never had any heating system leak so badly that the boiler was damaged while I did the inspection. A leak of that magnitude would be visibly obvious by wet carpet or wet flooring.

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The propane supplier I spoke to stated that hydronic radiant flooring systems generally use more propane than force air systems...

I think the propane suppliers forced air system has dehydrated his brain a little too much. That statement is about as Bass Ackwards as it gets.

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Ah! Got it Dave,

Guess you have 'challenges' closer to home than having to drive 300 miles to find more.

ghentjr,

I'm not suggesting that we are getting lazy or "not willing to do anything anymore" and that your test is not acceptable. I'm saying that if you turn off a safety device and forget about it, you'll be liable for the damages you cause.

Should we talk about leaving the oven on, letting the pool size jetted tub fill up past the overflow drain or looking at your jacket through the living room window in -30 degree weather after you've locked the doors. [:-crazy]

There are lots of ways to determine if a radiant system is leaking without shutting down controls.

Kyle,

As Bob would say............"FANTASTIC!"

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A leak of that magnitude would be visibly obvious by wet carpet or wet flooring.

A leak that would cause a dramatic spike in propane use also holds true. Things would be pretty dank in the old home front. Also a boiler that takes on continuous makeup water is one step away from a cracked heat exchanger. All the sediment drops to the bottom of the heat exchanger and acts like insulation between the flame and the water. The end result is that the heat exchanger overheats and cracks.

If indeed it's abnormally high propane use I'd put money on a leak - most likely outdoors. As they say in the city "propane shore is stinky".

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