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Type: Posts; User: sskzekeman

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1. ## Thread: Rate of heat rise calc....

by sskzekeman
Replies
22
Views
1,771

### I have a hot water baseboard heating system and ...

I have a hot water baseboard heating system and the off/on duty cycle equation I suggested for a furnace is invalid for me since my convective capability is far less than the hot water heater...
2. ## Thread: Rate of heat rise calc....

by sskzekeman
Replies
22
Views
1,771

### That's how you make a first test. If you divide...

That's how you make a first test. If you divide apples by apples, anyone knows you can't get oranges, or for that matter, apples.
As for significant figures, try your own tax return;if you get...
3. ## Thread: Rate of heat rise calc....

by sskzekeman
Replies
22
Views
1,771

### Well I have a more simplified way of doing this:...

Well I have a more simplified way of doing this:
But first the formula I suggested,
RATE OF RISE=RATE OF FALL*[T0/(70-T0)]
has an implicit assumption that the outside design temp, Td is 0 and that...
4. ## Thread: Rate of heat rise calc....

by sskzekeman
Replies
22
Views
1,771

### I respectfully disagree with that formula. First...

I respectfully disagree with that formula. First off it is dimensionally incorrect, i.e. dividing BTU/hr by BTU/HR cannot yield hours.
Also, you must know the rate at which it falls without heating ...
5. ## Thread: HVAC-Calc Calculated Heat Loss vs. Actual

by sskzekeman
Replies
14
Views
1,230

### You definitely have a thermostat problem if it...

You definitely have a thermostat problem if it takes 9 minutes to restart your furnace, especially since your house is so tight.And if your furnace data is accurate, I would take your test data over...
6. ## Thread: How far north are heat pumps effective?

by sskzekeman
Replies
48
Views
12,439

### I also live in southern CT and at my rate of...

I also live in southern CT and at my rate of \$.25/KWH, and assuming a COP of 3, I doubt that a heat pump is a good idea-- unless NG exceeds \$23/million btu.

So what am I missing?
7. ## Thread: Constant blower control to equalize temp?

by sskzekeman
Replies
3
Views
757

### If you run the fan constantly in the "on" mode...

If you run the fan constantly in the "on" mode rather than "auto" you would better equalize the temperatures or consider increasing the insulation to the lower room or if possible rebalance the flow...
8. ## Thread: What to do this fall?

by sskzekeman
Replies
8
Views
902

### I would either put in more attic floor insulation...

I would either put in more attic floor insulation or put in a temperature controlled attic fan and set the temperature to, say 80-85 in the attic or whatever temperature you would need to heat the...

by sskzekeman
Replies
8
Views
968

### You have an open circuit of the white common "c"...

You have an open circuit of the white common "c" wire" and tying the c to red was wrong and unnecessary since c was dead at the coil anyway. You had continuity of the ground (green) which was tied...
10. ## Thread: AC Motor Overheating Question

by sskzekeman
Replies
21
Views
2,922

### What I am saying is that most fan curves I have...

What I am saying is that most fan curves I have seen show a DECREASE in power at the same RPM when there is increased blockage of the ducting ,including increased resistance due to a dirty filter....
11. ## Thread: AC Motor Overheating Question

by sskzekeman
Replies
21
Views
2,922

### Regardless of the A/C usage the blower should be...

Regardless of the A/C usage the blower should be rated for continuous service and the Tech is absolutely wrong in his explanation, The filters have nothing to do with the problem as anybody in the...
12. ## Thread: Power factor converter

by sskzekeman
Replies
17
Views
1,783

### Power factor is, FYI, the cosine of the...

Power factor is, FYI, the cosine of the arctangent of the reactive impedance over the resistance.And the impedance Z is the vector sum of the resistance and the reactance

Moreover, contrary to...

by sskzekeman
Replies
32
Views
8,420

### Hey, moron What makes you think that a panel...

Hey, moron

What makes you think that a panel that develops 120 degrees without the coating will not have signiificantly more temperature at the panel under the coating which is a major thermal ...
14. ## Thread: Power factor converter

by sskzekeman
Replies
17
Views
1,783

### The "savings" to you would be infinitesimal; it...

The "savings" to you would be infinitesimal; it only the reduces heating loss in the house wires leading to the unit, called the "I squared R " loss. So your benefit would be almost zero since the...
15. ## Thread: How to best measure cycle frequency / run time

by sskzekeman
Replies
15
Views
1,564

### Last time I checked my ambient was 75 degrees.

Last time I checked my ambient was 75 degrees.

by sskzekeman
Replies
14
Views
2,191

### Get the subcooling and delta T across the...

Get the subcooling and delta T across the condenser. Also EER rating would help.
Overcharge causing excess subcooling or inadequate condenser airflow could be some of the causes.
17. ## Thread: How to best measure cycle frequency / run time

by sskzekeman
Replies
15
Views
1,564

### I never did this but he cheapest way to do it IMO...

I never did this but he cheapest way to do it IMO is to somehow hook up a 110 VAC electric clock to the furnace blower AC line ( must be 110 VAC) , but don't do it yourself. Get a sparky friend to...
18. ## Thread: rate of temperature decrease

by sskzekeman
Replies
1
Views
590

### The transient is irrelevant to performance, Just...

The transient is irrelevant to performance,
Just make sure the house can reach and sustain the setpoint temperature on the hottest and most humid oudoor conditions.
What you are asking is for...
19. ## Thread: No AC - 105 degrees today in N. Texas

by sskzekeman
Replies
11
Views
1,197

### Nobody asked me but.... Is it a good idea to run...

Nobody asked me but.... Is it a good idea to run an A/C unit when you're away for an extended period of time without having somebody checking it almost daily?
I don't think so.

by sskzekeman
Replies
17
Views
1,555

### Wow, What overkill for a simple problem unless...

Wow, What overkill for a simple problem unless you cant dump it outside.

by sskzekeman
Replies
17
Views
1,555

### Oh, I didn't notice. But with flow of condensate...

Oh, I didn't notice.
But with flow of condensate in winter no way could it freeze up anyway since it takes a lot of time to lose enough heat for freezing.

by sskzekeman
Replies
17
Views
1,555

### Why don't you leave it alone and don't worry...

Why don't you leave it alone and don't worry about freezing a condensate line you describe. So what if some residual water freezes in the winter; it shouldn't cause any problem unless you have some...

by sskzekeman
Replies
33
Views
16,274

### My bad, Upon looking into this more, it is...

Upon looking into this more, it is clear, as you say, that the enthalpy is practically independent of DB and virtually depends on WB alone.
That, however doesn't say that the same input...

by sskzekeman
Replies
33
Views
16,274

### Well since my charts show at 64 WB and outdoor...

Well since my charts show at 64 WB and outdoor ambient = 85 deg a range of 8 to 14 degrees SH for indoor DB range from 70 to 90 deg DB, The enthalpy of the 90 deg air and the 70 deg air differ...

by sskzekeman
Replies
33
Views
16,274

### Checking my tables, I find that the formula is ...

Checking my tables, I find that the formula is OK for WB temps >64 deg, indoor DB around 80 and ambient temps > 80 which makes it a rule of thumb formula.
Since it doesn't take account of indoor...
26. ## Thread: Suggestions for Lowering Fan Speed

by sskzekeman
Replies
18
Views
2,959

### Congratulations, Those are 2 of the worst "...

Congratulations,
Those are 2 of the worst " solutions" Ihave ever seen., especially burning up a motor with low voltage.
You are a lot smarter than that.
Reread all of the suggestions of the...
27. ## Thread: Suggestions for Lowering Fan Speed

by sskzekeman
Replies
18
Views
2,959

### Your cheapest solution as others have said is to...

Your cheapest solution as others have said is to increase the blockage either by installing a higher pressure drop filter, imposing a damper in the main duct or do something else to increase the...
28. ## Thread: I need some guidance to help my AC man...

by sskzekeman
Replies
41
Views
3,847

### quote " called him again, but it was working when...

quote " called him again, but it was working when he came by. Well, it stopped blowing cold again that night. I went outside and the outside AC fan was not on "

Could it be she means that the...
29. ## Thread: Another AC won't cool below 80F Problem

by sskzekeman
Replies
18
Views
4,090

### Fire this tech and get a competent one. Should ...

Fire this tech and get a competent one.
Should not have changed existing piston size. And should have taken airflow measurements and temps across the indoor coil.
Could be dirty coils in the...
30. ## Thread: High Superheat & High Subcooling

by sskzekeman
Replies
11
Views
8,283

### Adding more refrigerant is not indicated. You may...

Adding more refrigerant is not indicated. You may have more than enough. You have a faulty metering device or a restriction as you surmised and that problem must be adddressed first.
31. ## Thread: Analize This AC Preformance

by sskzekeman
Replies
12
Views
1,619

### Get the cfm, the supply and return WB temps to...

Get the cfm, the supply and return WB temps to get delta h to determine the actual system cooling.
32. ## Thread: Very Short Run Times this morning

by sskzekeman
Replies
49
Views
4,204

### It's possible too "cool" down quickly if the...

It's possible too "cool" down quickly if the supply register is near the Tstat and perhaps you have a near zero heating load which may include the morning sun or a hot attic even though the outside...
33. ## Thread: An epic question

by sskzekeman
Replies
29
Views
3,435

### quote: "My wife and I bought a townhouse in a...

quote:
"My wife and I bought a townhouse in a Minneapolis suburb less than a year ago. We’ve had a lot of fixes in that year, but we now have a problem with the AC. It appears to be leaking...
34. ## Thread: Add more returns or supplies to lower static pressure?

by sskzekeman
Replies
24
Views
2,659

Where is this reading or readings taken? Is it the ESP or is it the pressure in the duct downsream of the blower. If it is the latter then the .1" increase is not surprising. You blow more air,...
35. ## Thread: The new Heat Pumps still blow "cool" air?

by sskzekeman
Replies
18
Views
2,178

### COP *100 is the efficiency of converting electric...

COP *100 is the efficiency of converting electric energy into heating (or cooling.)
For example, if the COP is 2, then the eficiency is 200% meaning that each killowatt of usage delivers 2*3413...
36. ## Thread: Fan not running when on "Auto"

by sskzekeman
Replies
10
Views
1,686

### A limit switch iin the furnace senses...

A limit switch iin the furnace senses temperature near the heat exchanger which closes on a "minimum" temperature alllowing the fan to turn "on".(If the thermostat is in fan "on" mode then a...

by sskzekeman
Replies
3
Views
699

### Just in case somebody has a useful spreadsheet to...

Just in case somebody has a useful spreadsheet to help make decisions on whether to buy a heat pump vs electric heat vs gas or oilfired systems. Or someone else may have useful HVAC data in...

by sskzekeman
Replies
3
Views
699

Is there any way to add excel attachmentss to any posts here.
If not, why not?
I think it is important for this forum to have this capability.
39. ## Thread: 60,000 vs 80,000 btu

by sskzekeman
Replies
36
Views
21,610

### One other thing, if you may at some future date...

One other thing, if you may at some future date think of expansion, it may be a good idea to go with the larger unit.
Until then, if that furnace cycles too much, you could underfire the burners to...

by sskzekeman
Replies
4
Views
766

### Looking at that stat, I think , the tech should...

Looking at that stat, I think , the tech should be able to program it so that the auxilairy calls for "electric", but the output will go to the boiler control instead of the electric strip relay and...

by sskzekeman
Replies
12
Views
1,328

### Zoned heating probably would not work for a hot...

Zoned heating probably would not work for a hot air system, since the basement load is much smaller than the full house load. So, on a call for basement heat, the furnace would repeatedly go out on...
42. ## Thread: how can I est. oil consumption for a 2500sq

by sskzekeman
Replies
14
Views
1,251

### What is/was; Age of house Average outside...

What is/was;
Age of house
Average outside temperature durng those 50 days
Temperature setting of house
If I assume an average of 30 deg, then the total deg days would be
35*50=1750. If you used...
43. ## Thread: Motor amp draw

by sskzekeman
Replies
36
Views
6,729

### Richard, The difference is usually within the...

Richard,
The difference is usually within the accuracy of the measuring instrument, since the principle is a transformer where the primary is the single "turn" of the wire and the secondary is a...

by sskzekeman
Replies
24
Views
1,532

### Since the pump is running, it must be getting a...

Since the pump is running, it must be getting a tstat signal and a temperature indication that the water is warm enough to ciirculate so the air in line argument sounds reasonable.
45. ## Thread: Return Air Duct

by sskzekeman
Replies
11
Views
993

### Have a Tech measure the external static pressure...

Have a Tech measure the external static pressure to determine the actual cfm (from your chart) you are getting; there is a good chance you are getting sufficient airflow already and you can leave...
46. ## Thread: tweaking thermostat settings

by sskzekeman
Replies
49
Views
8,938

### I don't see much wrong with Dejouie's logic. ...

I don't see much wrong with Dejouie's logic.

You don't replace an existiing unit simply because it is oversized. If it runs 12 minutes every hour at design temperatures, it is probably 3 times...
47. ## Thread: Measuring efficiency of water heater

by sskzekeman
Replies
21
Views
2,331

### You are making an implicit assumptiion on the...

You are making an implicit assumptiion on the present and future cost of electricity. Do the math for the cost of electricity at 21 cents/KWH , my case and your conclusions would be wrong.
My cost...
48. ## Thread: Measuring efficiency of water heater

by sskzekeman
Replies
21
Views
2,331

### I did a quickie at one time during the summer and...

I did a quickie at one time during the summer and assuming the builtin aquastat temp differential and a firing rate of my .75gph nozzle, like you, I was satisfied that the 80% efficiency I quoted was...
49. ## Thread: Measuring efficiency of water heater

by sskzekeman
Replies
21
Views
2,331

### First off, you should have the HWH tuned by a...

First off, you should have the HWH tuned by a professional and get a combustion efficiency readout before you condemn it. A modern HWH can give you in excess of 80+ % efficiency and could handle...
50. ## Thread: tweaking thermostat settings

by sskzekeman
Replies
49
Views
8,938

### To put this in perspective, increased cycling...

To put this in perspective, increased cycling controls the temperature more closely by reducing the swings but at the expense of inefficiency. If he is not concerned about the swing ( 1 degree) he...
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