Heat loss calculations?

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  #41  
Old 12-01-14, 10:27 PM
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I'm typing this on my phone so sorry for any errors. Sorry to hear that these health issues are still giving you a problem, I truly wish you a speedy and full recovery. Thank you so much for helping me out despite your illness, again if there's anything I can do to help don't hesitate to ask. I can't find any labels that speak to a specific max temp differential but it does list a maximum discharge temp of 200F, it also says "min spd tap Lo" if that helps. I'm going to try and find a proper analog thermometer and I'll drill the holes and report back with better measurements. Probably won't get that done till Wednesay though. I would love for you to come visit and feel honored that you would even consider it! When you're feeling up to it let me know and we can work out the details. I'm nearest to Covington, kind of smack dab in the middle of good ole unincorporated South King County. I'm a 5-10 minute drive off of the Kent-Kangley Rd exit on Hwy 18.
 
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  #42  
Old 12-01-14, 10:32 PM
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And yes, I can leave the grilles off, my giant lab/husky mix might try to get his head in there but I doubt it'd fit... And the filter is brand new, changed it last time I had the panel off to change the blower speed.
 
  #43  
Old 12-01-14, 11:40 PM
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Okay, substitute the red blower motor lead for the yellow now connected. That should cause the on times to increase somewhat although it may not make a significant difference with the off time. If the blower noise is not too obnoxious you can try adding the jumper again between the R and G terminals to keep the blower running constantly. Continuous blower operation should bring the house to an even temperature throughout. Don't pay too much attention to the displayed temperature on the thermostat but adjust it up or down to a point of maximum comfort. You CAN go back to a setback program if desired but don't set back more than about four degrees maximum or recovery will definitely suffer during the colder weather.

Note, because of the type of blower motor you have continuous operation will increase the electricity usage by a noticeable amount, I only want to see if this increases the comfort level and if using setback with continuous blower operation allows for a fairly quick return to desired temperature. Once we determine the optimum blower setting with your oversized furnace and woefully undersized ductwork we can move on to what things you might be able to do to make the system right.

I have a close friend that lives in Covington so I am not entirely unfamiliar with the area. Maybe I can make it down that way but I suspect not until after Christmas. I go back to the hospital tomorrow for more tests, should be just an hour or two.
 
  #44  
Old 12-02-14, 09:55 AM
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I will make the recommended changes and report back, probably won't get be able to get all this done til Weds or Thurs but I'll be sure to get it done as soon as I can. Good luck with your tests!
 
  #45  
Old 12-04-14, 09:33 PM
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Hope your tests went well Furd! Mine, not so much... Not sure what happened but the red (slow) fan lead isn't working anymore, double checked the connection but with the red lead hooked up the fan won't spin at all. Went back to yellow and everything works again. Time for a new blower motor? Is there any troubleshooting I should do with this one first? Hope you're feeling better, thanks again for all the help.
 
  #46  
Old 12-05-14, 12:20 PM
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Well, that sure puts a damper on the festivities!

I don't know what to tell you now. Honestly, I would rather you save your money for a new furnace and ductwork corrections than to sink any large amount of money into this one. I guess that means you have to go back to the yellow lead and suffer with the noise.

Sorry.

Oh, they were lung capacity tests and (as usual) the technician couldn't tell me if mine were good, bad or average. I see the doctor on the 16th.
 
  #47  
Old 12-06-14, 11:26 AM
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Well if you managed to finish the tests without passing out and your doctor's not beating down your door to get you in sooner than the 16th that's probably a good sign Thanks again for all your help, I wish you continued luck and good health.

Just got my PSE bill, after adjusting for an extra 2 days in last years billing cycle I used 420 kWh less this year than last with relatively similar weather. I'm assuming that's a combination of the new insulation and our modifications to the furnace so thank you for that. Am I crazy to think though that 2,600 kWh is still insanely high for 2 people living in a 1,700 sq ft house when the average temp was 43? Last month without using the furnace (average temp 63) we only used 510 kWh so the furnace is definitely the culprit.

With the red blower lead dead I'll leave things alone as you suggested, I hope you'll still consider a road trip after the holidays or when you're feeling better. If duct work and/or the furnace needs to be replaced I assume I'll call a pro in for that but your consultation would be invaluable and much appreciated.

Thanks again,

-JR
 
  #48  
Old 12-06-14, 01:52 PM
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Thank you for the well wishes. I'm not going to die anytime soon. As I tell anyone that will listen I have far too many people to irritate before I die.

Your numbers actually sound good. Remember, even in this land of (relatively) cheap electricity electric heat IS still expensive. Using those figures I calculate about a 20% reduction from the previous year and that's not at all shabby.

My teachers always told me to "show your work" but I'm not going to this time. Subtracting that 510 kW hr. "other usage" from the bill and then working the numbers gives me a figure of 2,090.6 kW hrs. for heat. That translates to about 7,135,260 BTUs per month or about 9,910 BTUs per hour. Dividing that by your square footage gives a figure of about 5.83 BTUs per square foot per hour. My friend NJ Trooper (moderator of the boilers forum) likes to tell people that a figure below 25 BTU per square foot is a good number so that alone puts you in the very good category.

My own house, 1550 square feet on one level and not all that well sealed or insulated used 90 Therms of natural gas as of late last month, in contrast you would have used about 84 Therms if you had an 80% AFUE (efficiency factor) gas furnace so you are doing better than I. My gas bill was for about $107 vs. your electric heat billing at about $209. (based upon an average cost of ten cents per kWh hour). If there is any way you could retrofit a gas furnace you would be wise to consider this action.


I want you to do another test, this time replace the jumper between W1 and W2 and then check the discharge temperature and the differential temperature. Check after the furnace has run for ten minutes, turn the thermostat way up if necessary to keep it running this length of time. After the test remove the jumper. If the results are a discharge temperature less than about 150-175 degrees and a differential less than about 60 degrees I then want you and your wife to think hard about a new thermostat.

Adding a new two-stage thermostat will allow you to use the deeper setbacks (if desired) and still have a reasonable "pick up" time when the temperature is raised to the normal setting. At all times other than pick up the furnace will run on only one stage of heating but it will automatically switch to the second stage if the measured temperature falls a specific number of degrees below that normal setpoint.

There may be a couple of other things that can be done to help the overall situation, but I don't think I can make that call over the Internet. I'm not ruling out the road trip.
 
  #49  
Old 12-12-14, 11:13 AM
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Thanks for the reply and sorry for taking so long to get back to you, holiday stuff and work has kept me busy. Glad to hear you're doing well and have no plans to shuffle off that mortal coil just yet, we need you around here a little longer!

Thank you for crunching those numbers, that definitely makes me feel a little better. We are definitely very interested in upgrading the thermostat so I will get you those numbers with the second element engaged and hopefully they will fall into an appropriate range. I'd love to switch over to gas but there's no municipal service here so we'd have to have an outdoor tank installed and that seems like more trouble than it's worth. Eventually maybe if we redo the kitchen so we can get gas appliances in there maybe it'd be something to consider, but for the time being I think we're stuck with all electric.

I sent you a PM, not sure if this conversation is getting too specific to keep going here or not so get back to me here or there and let me know what you think. Thanks again!

JR
 
  #50  
Old 12-12-14, 03:30 PM
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Hi again as I'm still following. Where your temperature rise is a function of the size of your furnace and its delivery system, the temperature fall is more a function of your heat loss. In addition to the work you are doing here, it still sounds like progress could be made by reducing the total heat loss. This would definitely be better handled under a new thread so if in the future you wish to look at that there are several here that can help.

Best
Bud
 
  #51  
Old 12-13-14, 12:29 AM
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With no natural gas available your are pretty much stuck with the electric as propane is almost the same price as oil.

As long as we are discussing the furnace I think it is best to continue with this thread. After that is finalized then a new thread to discuss further insulation and air sealing of the house should probably be started.

I expect to be fairly busy the next few weeks with doctor appointment, hospital visit to finally remove the kidney stone and also my sister's son is arriving for a short stay and to help me get some things accomplished in my own house.
 
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