I have found the flags to be unreliable also. You can do almost anything with EMS, so it should be possible to input a “snow schedule” that makes the EMS operate
high output snow melt. You would have to decide for yourself what the snow fall parameters would be for system operation.
Ned Lyon, P.E. (MA)
Staff Consultant
SIMPSON GUMPERTZ & HEGER
781.907.9000 main
781.907.9350 direct
781.907.9009 fax
www.sgh.com
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx]
On Behalf Of Karen Walkerman
Sent: Friday, December 09, 2011 2:58 PM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: Re: [EnergyPlus_Support] Snowmelt
Hi Edward,
Thanks. I'm fairly familiar with how snowmelt systems work - I've run some excel calculations based on hourly weather files using the outdoor air temp to calculate "standby" losses and the snowmelt flag coupled with total yearly snowfall
to estimate total energy use. Standby losses are definitely a large part of the equation. I'd love to be able to use EP to simulate something like this, but you're right - it's not just EP, it's also the weather files. Maybe EP could use a combination of
a "snow-flag" and some user-entered values about the average annual snowfall to develop the information needed to run the simulation.
--
Karen
On Fri, Dec 9, 2011 at 2:45 PM, Edward G. Lyon <eglyon@xxxxxxx> wrote:
At least one issue is the current weather files seldom have reliable precipitation data. Typically a snow melt system remains on in larger installations because it takes too long to heat the slab and ground if it
is only turned on for a snow event. The new systems have a low output standby heat setting with moisture sensors to trigger high output snow melting.
Ned Lyon, P.E. (MA)
Staff Consultant
SIMPSON GUMPERTZ & HEGER
781.907.9000 main
781.907.9350 direct
781.907.9009 fax
www.sgh.com
From:
EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx]
On Behalf Of Karen Walkerman
Sent: Friday, December 09, 2011 2:38 PM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] Snowmelt
Has anyone used EnergyPlus to model snowmelt? Snow-melting is mentioned under "GroundHeatExchanger:Surface", but I am skeptical about actually using this object to melt snow. Does this object model the additional heat lost from the surface in order to melt
snow? Does it model the insulating properties of the snow if the slab is not warm enough to melt the snow?
I'm looking for any feedback, ideas or discussion.
Thanks!
--
Karen
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