Got Data? How much leaking electricity is there in HVAC systems?

I poked around when shopping for fuel-firedboilers and couldn't find anything official.  Ran across estimates ranging from a few watts to 30 watts.  Anyone have data or pointers to data?  A lot of effort has been spent on understanding "leaking electricity" from appliances, but what about HVAC? Seems like a sleeper to me.

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This is what I have from some of our Baseload auditing:
Compressor Crankcase Heater in AC: 40 W
Zone Dampers on Air Handler: 30 W
Thermostat transformer: 4W
And... of course the 't-stat fan setting set to "on" always' which can be:
Airhandler fans on 24/7 (@400-600W)
500W x 24 hours x 365 days x .001kW/W = 4,380 kWh/yr @$.16 = $701 per year
Tamasin:

You are really making every opportunity to hammer home that "fan on" issue :-).

Regarding the math, I usually skip a term by going straight to 8760 hr/yr...sounds much more impressive :-). Anything multiplied by that number is a bunch :-)

And $0.16/kWh !! I'm crying the blues at $0.14 in NV!

Can not be said too often!
Can't tell you anything about boilers, but I could look up measured data for my own ECM furnace if that helps. If memory serves it was on the order of 10 watts total. I believe Scott Pigg of the Energy Center of Wisconsin has data for furnaces, but probably not boilers - he might have published the furnace standby in his Home Energy Magazine article of Nov/Dec 2003.

You might try posting this question on "The Wall" at HeatingHelp.com. This is Dan Holohan's web site, and some experienced hydronic contractors often give prompt answers to questions.

Alan Meier sent me to the Australian Standby Power study linked here: http://standby.lbl.gov/docs.html several years ago, but I don't recall if boilers were measured. Great study because it measured a lot of hard-wired sleepers, as you called them.

If you find good data please publish it - inquiring geeks want to know!

Upstate NY is coming in at $.17/kWh

Steve Waclo said:

Tamasin:

You are really making every opportunity to hammer home that "fan on" issue :-).

Regarding the math, I usually skip a term by going straight to 8760 hr/yr...sounds much more impressive :-). Anything multiplied by that number is a bunch :-)

And $0.16/kWh !! I'm crying the blues at $0.14 in NV!

Can not be said too often!

Mark:

 

"Upstate NY is coming in at $.17/kWh"

Does the meter reader wear a Lone Range mask on his rounds :-)??

Spent the coldest winter ever in Corning back in 99-00 and noticed how the state seemed to load up utility bills with surcharges. Corning Glass was booming at the time, but pity folks who had to pay the heating costs when things declined there later.Understand CG is now coming back.

The only electrical stand by losses I believe would be from the control transformer. If there is no call for heat.



Steve Waclo said:

Mark:

 

"Upstate NY is coming in at $.17/kWh"

Does the meter reader wear a Lone Range mask on his rounds :-)??

Spent the coldest winter ever in Corning back in 99-00 and noticed how the state seemed to load up utility bills with surcharges. Corning Glass was booming at the time, but pity folks who had to pay the heating costs when things declined there later.Understand CG is now coming back.

 

They wear a mask, but it ain't Lone Ranger or Robin Hood!

Actually just about HALF of the electric cost (I'm in Central Hudson territory) is fees and transmission charges. You 'only' pay about $.08-.09/kWh for the electricity, the rest is delivery.

Just got some measurements from one boiler.

 

Heating mode: 936W

Circ pump and air handler: 396

Circ pump only: 216W

Cooldown (internal fan): 120W

All "off": 3.6W

If it's leaking, while it certainly does affect efficiency, wouldn't this nevertheless already have been calculated?

If not, then a 14 seer pump is not a 14 seer.

If I may chime in, the newer hydronic boilers, (Viessmann Vitodens 200 being one I have personally installed, but others as well), often do cause an unexpected electrical consumption jump -at least the first time you install one. In our case, the internal blower fan and internal circulator (an ECM based Grundfos just the same), drew over 130 Watts over our previous baseline. The heating efficiency was admirable and worth it, but we paid no mind to the electrical consumption until we got the bill. I installed a Kill-A-Watt meter at the power supply unit for a season and it recorded over 600 kWH for a ten month period. This does not include the secondary circulator for the heating loop. We average about 18 cents per kWH here in Boston, BTW.

These are net boiler numbers. Our first month was double this but we found the culprit: When the boiler fired it created the tell-tale condensing boiler plume. The plume in turn activated the IR/Motion Detector on our outdoor flood lights... live and learn.

Tamasin illustrates the much larger parasitic losses of moving air. All that mass of low specific heat vs. water, it is not an efficient delivery method. The Btu per Watt ratio is rather low.

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