Would you ever at your own home…

Mosherd1

Since we got our first measurable snow fall today and we’re in the middle of another major home renovation (this time it’s my mom’s house), it has me thinking how much I hate to shovel snow.  Would you ever use a pool heater for a snow melt system at your own house. I have been gifted a 150,000 btu fully functional older Hayden pool heater. It’s an exterior heater and I know it is the wrong product for this application, but I have about 600 Sq ft of concrete and 150,000 @ 78% =117,000, so that gives me just under 200 btus/Sq ft.  It was free and I have no other use for it, other than to sell it on Craigslist. The system would probably be run between 5-20 times per season. So, if it was you, would you use it until it craps out in time, or would you buy a new boiler right from the start. 

EBEBRATT-Ed

I suppose it can be made to work. I would look closely at Hayden's flow and temperature requirements for the pool heater and make sure you are flowing the right gpm and at a temp the pool heater can handel, also that it will work with glycol as it will have to be outside

hot_rod

While not officially a listed ASME device they have been used successfully for that application. Most copper tube pool boilers have a thermostatic return protection valve built into the headers, since they run at below condensing temperatures most of their life in a pool application. Check the spec sheet to see what the minimum gpm required is.

pecmsg

When you get the fuel bills you’ll question that idea. 

Mosherd1

@pecmsg my all in cost of natural gas is ~$0.85 per therm so it’s a $1.28 per hour to run. This as for my elderly moms house, if I can’t get over there in time to shovel and the system has to run 10 hours that’s just over $12 per snowfall, and then I don’t have the hassle of trying to line a kid up to shovel which would probably cost more as it is. 

pecmsg

Mosherd1 said:

@pecmsg my all in cost of natural gas is ~$0.85 per therm so it’s a $1.28 per hour to run. This as for my elderly moms house, if I can’t get over there in time to shovel and the system has to run 10 hours that’s just over $12 per snowfall, and then I don’t have the hassle of trying to line a kid up to shovel which would probably cost more as it is. 

That’s fine. 

JakeCK

Where are you located? What I've always heard is that snow melt systems need to pretty much run all winter(or whenever the temperature is supposed to get close to freezing to be effective. If you're climate is anything like where I'm at I think you need to consider the thermal mass of the concrete too. You won't be able to just turn it on a few hours before snowfall in the middle of January at 15f and expect it to keep the driveway free and clear a few hours later. It'd take a day(s) for it to heat up that slab of concrete that's at an ambient temperature well below freezing. And you'll have to run it long after the snow stops flying to dry it too. Other wise it will just cool back down and the now melted snow will turn into a sheet of ice. 

But I'm not an expert. So take what I say with a grain of salt.

hot_rod

Good points @JakeCK. It is tough to start melting when the snow starts. It could take 250 btu / foot to start and keep up with a snowfall. Hospital helipads design around high btu output, for example, no accumulation, no striping allowed

The melt waters need to run off the slab to prevent ice when it shuts down, a sloped slab works best.

It can be a substantial amount of water to drain off. Ask anyone with a downward sloping snowmelt drive to garage for example

Zman

Hook it up!
In the late '90s and early 2,000s very similar out door rated boilers from Laars and RayPak were super popular for snowmelt systems. At ~200 BTU/Ft your system will kick butt.

JakeCK

Zman said:

Hook it up! In the late '90s and early 2,000s very similar out door rated boilers from Laars and RayPak were super popular for snowmelt systems. At ~200 BTU/Ft your system will kick butt.

No argument that it won't work. But I suspect it's going to cost more than he expects for it to be effective. I doubt he could turn it on at the start of a good snow storm and expect to be able to turn it off half a day later... I'd wager a bet a single day long storm would take at the very least 2 days to clear and dry the slab. Using his math that's easily 60$. Do that a couple times in one month and all of a sudden the teen next door is looking a lot cheaper.

Full disclosure: I'm the guy who doesn't even shovel his driveway. 4x4 with gnarly tires and a 9500lb winch means I give 0 f***s about snow.

hcpatel78

Mosherd1 said:

@pecmsg my all in cost of natural gas is ~$0.85 per therm so it’s a $1.28 per hour to run. This as for my elderly moms house, if I can’t get over there in time to shovel and the system has to run 10 hours that’s just over $12 per snowfall, and then I don’t have the hassle of trying to line a kid up to shovel which would probably cost more as it is. 

Just got a bill in Newjersey the Natural gas rate is $1.2521 per Therm. 33% up compared to last year.

JakeCK

1/20 217ccf 37.7f 34days 6.4ccf/day $.4249/ccf

1/21 240ccf 34.3f 34days 7.1ccf/day $.4420/ccf

1/22 184ccf 39.9f 34days 5.4ccf/day $.6410/ccf

31% increase in Cleveland.


Edit: So I pulled up the spreadsheet that has all the data from my gas and electric bills. For 1/16 I used 183ccf, it was 41.6f avg and the billing cycle was 34days. I still used 5.4ccf/day, very comparable to this past month. I have remodeled and insulated my whole kitchen, removed a chimney, replaced the chimney cleanout doors on the remaining two, added a vent damper on the boiler, airsealed between the basement and attic, and even replaced the 14yr old gas WH with a HPWH. Granted that last on is a wash because the heat ultimately comes from the boiler. but all of that has done absolutely nothing to reduce my gas consumption. LOL NOTHING! And I don't have a small kitchen. It extends out from the back of the house and half of it has an exposed ceiling. None of it was insulated before and now it all is. 

I quit. Lol

EdTheHeaterMan

If you are considering Snow Melt as an option, and you are going to purchase a boiler for that reason, install the tubing to the maximum size needed to resolve the expected snowfall. Even if the boiler you have is smaller than you would probably purchase for the job. Use the pool heater. if it works, then you're done.

If you need a bigger boiler... at least the "inslab" piping is able to handle the larger boiler.

Mosherd1

Comparing natural gas from year to year Dec. 2020 81.74 therms used, cost per Them $0.4240274; does not include monthly customer charge of ~$20 just to have a meter. Dec 2021 they had a rate change for delivery cost but it works out to $0.8565 per Therm, not including customer charge. 

pauliewalnutz

Also make sure to use insulation under the pex to direct heat to the surface. 2” foam board works. 

jumper

Do you use a machine or a shovel? When I was a young man I & my big snowplowshovel cleared driveways briskly. Then there was the guy who'd crank up the pressure on his steam boiler .....