Anyone have a suggestion for standby whole home generator? - Home Improvement

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pandora Premium join:2001-06-01 Outland kudos:1 Reviews: ·Google Voice ·Comcast ·ooma ·Future Nine Corp..	reply to pferrie3 Re: Anyone have a suggestion for standby whole home generator? said by pferrie3: i think the whole point harry's making is it will take 3 times the propane to make electricity to convert back to heat .. than to just use propane to heat .. so the propane will last longer I haven't performed a full calculate the conversion rate between 18 SEER heat pumps, propane used to make electricity and direct propane per BTU. The unit specification is here - »www.goodmanmfg.com/Portals/0/pdf···ZC18.pdf you'll want to look at the 4 ton unit. At 95F degrees outside, to produce 70F degrees inside at high airflow it looks like 1.67 KW per unit, or slightly over 3 KW for 2 units. At -10F outside to produce 70F indoors seems to require 2.66KW per unit, or about a bit over 5 KW. If it goes below -10F, I guess the 20 KW heater elements will try to fire and be shut down. In Connecticut, according to »www.weather.com/weather/wxclimat···ph/06813 once in history we had a -18F day. All other months have a maximum of -10F or less. So unless it's a power failure on an unusually cold winter day, the heat pumps should work fine of 5 KW at -10F. The average low is +19F in January, which is well within the tolerance of the units. The spec for the house is 77F in winter with the heat pumps down to 0F, and 68F in summer up to 110F. The units were sized with a heat loss computation using the blueprints we are building to. Installation of a propane heat element, would likely be expensive and only cover the outlying situation when we have temperatures below -10F. -- "People demand freedom of speech as a compensation for the freedom of thought which they seldom use."
	to forum · permalink · 2012-09-23 14:59:51 ·
laserfan join:2005-01-14 Blanco, TX	reply to Mr Matt said by Mr Matt: Your main breaker can trip if the loading on the legs of your 120 Volt circuits are severely unbalanced even if the total load does not exceed 200 Amps. If one leg is carrying over 200 Amps breaker trips. Check with clamp on amp meter. If you add a generator be aware that most generators cannot accept an unbalance of greater than 50% between each 120 Volt Leg. I did not know this, and it does certainly complicate my idea that on a power failure I would first set a number of breakers to OFF before firing-up the Generator and throwing a transfer switch. Thanks for the info. FWIW I don't think our 200A breaker tripping was due to imbalance, but rather: it was very, very cold, multiple blowers with heat strips were On, pool pumps were Running as they do below 35F, and probably the wife was doing laundry (Electric Water Heaters) and all these are 240VAC. Too many loads on at once. With a whole house genset I'd still on a power failure want to force some number of these Off, e.g. nonessentials like the water heaters...
	to forum · permalink · 2012-09-23 15:06:09 ·
HarryH3 join:2005-02-21 kudos:1 Reviews: ·Suddenlink	reply to pandora said by pandora: said by HarryH3: I believe that the point that was being made is that it takes far less generator to power the propane furnace than it does to power electric strips. The likelihood the strips will be used for any length of time is near zero. Did you not see that this thread is about a GENERATOR? Why burn a huge amount of propane, to generate electricity, to run a heat pump compressor (or heat strips) that finally heats the house? The OP can buy a MUCH smaller generator if he just burns the propane directly in a furnace.
	to forum · permalink · 2012-09-23 15:16:04 ·
pandora Premium join:2001-06-01 Outland kudos:1 Reviews: ·Google Voice ·Comcast ·ooma ·Future Nine Corp..	said by HarryH3: said by pandora: The likelihood the strips will be used for any length of time is near zero. Did you not see that this thread is about a GENERATOR? Why burn a huge amount of propane, to generate electricity, to run a heat pump compressor (or heat strips) that finally heats the house? The OP can buy a MUCH smaller generator if he just burns the propane directly in a furnace. Heat pumps heat AND cool a home. Propane furnaces, not so hot for cooling. The use of the 2 heat pumps is about 5-6 KW, not certain what the air handlers use, but likely less than another 1-2KW. An entirely separate propane heating system, for times when the power would be off, really isn't cost effective. The BTU output of each unit is 47,000 BTU/hour, around 90,000 BTU. Over here »www.ask.com/answers/142644781/ho···n-of-lpg it says an 80,000 BTU/hour propane heater would consume about 3.2 gallons per hour. My generator would consume a bit more, but not need a separate flue, need carbon monoxide detectors, or blowers, and the only use for the propane heater would be when there was no power (about 3 days per year averaged out over the past 10). The cost of a flue, propane furnace, hookup to 2 air handlers, carbon monoxide detection, and maintenance would surely exceed any savings for a few days of power outage. -- "People demand freedom of speech as a compensation for the freedom of thought which they seldom use."
	to forum · permalink · 2012-09-23 16:44:06 ·
nunya Who is John Galt? Premium,MVM join:2000-12-23 O Fallon, MO kudos:8 Reviews: ·Charter ·surpasshosting ·voip.ms	The cost of a flue, propane furnace, hookup to 2 air handlers, carbon monoxide detection, and maintenance would surely exceed any savings for a few days of power outage. You may be surprised. That's why I advised you to at least "look into" using propane furnaces rather than electric resistance furnaces as backups to the heatpumps. The operational limits of air source heatpumps tend to be greatly exaggerated (especially by their fanboi's on this site). While they are great if you live in a milder winter climate, they lose efficiency fast the colder it gets. Trust me, it will be well above -10 when the air source heatpumps will not be able to keep up with your heating demands by themselves. You should consider the cost of propane / btu vs. electric / btu only so far as the "auxiliary" heat is concerned (resistance heating). Naturally, a power failure is most likely to occur during extremely inclement weather (coldest or hottest). Unfortunately, the price of propane isn't nearly as stable as electric rates, but both are subject to fluctuation. This "dual hybrid" scenario actually makes a lot of sense when a generator is thrown into the mix. The potential for savings isn't going to be just "generator" time, but any time in the colder months when the auxiliary heat must fire up to keep your house comfortable. This is going to happen a lot more than you might expect. -- If someone refers to herself / himself as a "guru", they probably aren't.
	to forum · permalink · 2012-09-23 18:26:37 ·
fifty nine join:2002-09-25 Sussex, NJ kudos:2	The main problem I have with propane is the propane mafia. If you're going all in with propane and lease your tank be prepared to call your propane company every season and haggle. Otherwise be prepared to pay megabucks to install your own tank.
	to forum · permalink · 2012-09-23 18:42:59 ·
SwedishRider Rider on the Storm Premium join:2006-01-11 Connecticut kudos:1	said by fifty nine: Otherwise be prepared to pay megabucks to install your own tank. Megabucks? Hardly. I paid $1800 for the underground tank and $400 for installation. That's hardly megabucks compared to what I've saved vs a leased tank in 3 heating seasons.
	to forum · permalink · 2012-09-23 18:55:30 ·
herdfan Premium join:2003-01-25 Hurricane, WV	reply to Mr Matt said by Mr Matt: Consider that the oil change interval on the GE/Briggs and Stratton is 100 Hours or One Year while the oil change interval on the Generac is 200 Hours or Two Years. ..... while the Generac would require an oil change every Eight Days. Since I immediately fired my Generac up as we were in the middle of a power outage, I changed the oil after about 16 hours which was more than the 8 it recommended. But the change took me about 10 minutes and I was back up and running. It has a nice oil drain hose. No mess at all.
	to forum · permalink · 2012-09-23 19:38:56 ·
herdfan Premium join:2003-01-25 Hurricane, WV	reply to pandora said by pandora: Heat pumps heat AND cool a home. Propane furnaces, not so hot for cooling. The use of the 2 heat pumps is about 5-6 KW, not certain what the air handlers use, but likely less than another 1-2KW. An entirely separate propane heating system, for times when the power would be off, really isn't cost effective. The BTU output of each unit is 47,000 BTU/hour, around 90,000 BTU. The cost of a flue, propane furnace, hookup to 2 air handlers, I have 2 heat pumps. One has heat strips for Emergency or Aux. heat. The other has a NG furnace. The HP works as a HP until the outside temps drops into the 40's, then the Emer/Aux. heats kicks in. But I rarely use the electric heat strips as the NG furnace in the basement puts out enough heat to keep the whole house warm. As for the cost of the flue, the new efficient models use Schedule 40 PVC with a blower. Not much expense at all. Plus, and I am sure I will get arguments here, but propane and gas heat feel warmer than electric. Maybe it is because it is more humid heat and feels warmer, I don't know. But it does to me.
	to forum · permalink · 2012-09-23 19:45:35 ·
Mr Matt join:2008-01-29 Eustis, FL kudos:1 Reviews: ·CenturyLink ·Comcast ·Embarq Now Centu..	reply to pandora Pandora, I was not able to find a comment in this thread regarding how various heat pumps operate while in the defrost mode. In my case when each heat pump goes into the defrost mode the compressor and heat strip operate together. My condensers and air handler fans draws a total of 41 and 45 Amps respectively at 240 Volts when in the defrost mode. The heat strip in each system is rated at 4.8 KW or 20 Amps at 240 Volts. A generator powering my 30,000 BTU heat pump in the defrost mode would have to supply 41 Amps or 9840 Watts and my 42,000 heat pump 45 Amps or 10,800 Watts. That total requirement would exceed the capacity of a 20,000 Watt generator which is why a load management system is required to use a 20,000 generator in my home. That is probably why one Generac dealer recommended a 36Kw generator for my home if I stayed all electric. I agree with nunya that if you can use propane rather than electric heat strips for back up heat you can use a smaller generator and in my opinion your system will probably provide better quality heat. The key facts that one has to review is the total capital investment in you appliances for an all electric solution and the total capital investment for a propane/electric solution, along with the yearly operating cost and how long you plan to remain in this house. If the difference in cost is significant, I would also consider the convenience factor for the two different systems, to determine if the more expensive solution is better.
	to forum · permalink · 2012-09-23 19:48:20 ·
nunya Who is John Galt? Premium,MVM join:2000-12-23 O Fallon, MO kudos:8 Reviews: ·Charter ·surpasshosting ·voip.ms	Defrost mode is a big problem. In theory, you could defeat the electric strips to keep them from running at the same time as the heatpump. You don't want your heatpump to skip defrost mode, especially when it's cold outside. It will literally (in Chris Traeger style) turn into a block of ice. I've had this happen (bad defrost timer), and it's always in the coldest part of the year (murphy's law). I'm fortunate that where I'm at now is NG, but I plan on moving to the country soon, and I'm afraid heatpumps may be in my future. I will still probably have propane backup (and for other heating appliances). -- If someone refers to herself / himself as a "guru", they probably aren't.
	to forum · permalink · 2012-09-23 21:56:25 ·
pandora Premium join:2001-06-01 Outland kudos:1 Reviews: ·Google Voice ·Comcast ·ooma ·Future Nine Corp..	reply to nunya said by nunya: I've had a Ruud 14 SEER heat pump for about 7 years (forget the heat pump spec, but the AC is 14 SEER). Last year, on all but 1 day, in Connecticut we survived without auxiliary heat. Auxiliary heat was on for about a 6 hour period a few hours before and after dawn. I've kept my home at 77F in winter at 10F outside with the existing Ruud. Our new heat pumps are somewhat newer, have improved performance, and will be installed in a better insulated (though much larger) home. If the heat pumps fail, and I spend thousands of dollars on resistive heat, I'll investigate a propane auxiliary heat system. Though I appreciate your help. It is my amazingly positive experience, with a now somewhat older heat pump, that causes me to have some confidence in the newer units. -- "People demand freedom of speech as a compensation for the freedom of thought which they seldom use."
	to forum · permalink · 2012-09-23 23:14:30 ·
pandora Premium join:2001-06-01 Outland kudos:1 Reviews: ·Google Voice ·Comcast ·ooma ·Future Nine Corp..	reply to herdfan said by herdfan: I have 2 heat pumps. One has heat strips for Emergency or Aux. heat. The other has a NG furnace. The HP works as a HP until the outside temps drops into the 40's, then the Emer/Aux. heats kicks in. But I rarely use the electric heat strips as the NG furnace in the basement puts out enough heat to keep the whole house warm. As for the cost of the flue, the new efficient models use Schedule 40 PVC with a blower. Not much expense at all. Plus, and I am sure I will get arguments here, but propane and gas heat feel warmer than electric. Maybe it is because it is more humid heat and feels warmer, I don't know. But it does to me. If I had NG on my street, I'd have kept my old furnace. The problem is I don't. It's electric or propane. Electric rates seem to be more stable over time imo. -- "People demand freedom of speech as a compensation for the freedom of thought which they seldom use."
	to forum · permalink · 2012-09-23 23:16:09 ·
pandora Premium join:2001-06-01 Outland kudos:1 Reviews: ·Google Voice ·Comcast ·ooma ·Future Nine Corp..	reply to Mr Matt said by Mr Matt: Pandora, I was not able to find a comment in this thread regarding how various heat pumps operate while in the defrost mode. In my case when each heat pump goes into the defrost mode the compressor and heat strip operate together. My condensers and air handler fans draws a total of 41 and 45 Amps respectively at 240 Volts when in the defrost mode. The heat strip in each system is rated at 4.8 KW or 20 Amps at 240 Volts. A generator powering my 30,000 BTU heat pump in the defrost mode would have to supply 41 Amps or 9840 Watts and my 42,000 heat pump 45 Amps or 10,800 Watts. That total requirement would exceed the capacity of a 20,000 Watt generator which is why a load management system is required to use a 20,000 generator in my home. That is probably why one Generac dealer recommended a 36Kw generator for my home if I stayed all electric. I agree with nunya that if you can use propane rather than electric heat strips for back up heat you can use a smaller generator and in my opinion your system will probably provide better quality heat. The key facts that one has to review is the total capital investment in you appliances for an all electric solution and the total capital investment for a propane/electric solution, along with the yearly operating cost and how long you plan to remain in this house. If the difference in cost is significant, I would also consider the convenience factor for the two different systems, to determine if the more expensive solution is better. Good point, DLM will turn off any large appliance that draws too much off the generator. My understanding is I have 83 amps more or less stable from a 20KW generator. We shall see what happens. It'll be interesting. As to propane auxiliary heat, not going to happen, unless the electric bill is extremely high. -- "People demand freedom of speech as a compensation for the freedom of thought which they seldom use."
	to forum · permalink · 2012-09-23 23:26:29 ·
nunya Who is John Galt? Premium,MVM join:2000-12-23 O Fallon, MO kudos:8 Reviews: ·Charter ·surpasshosting ·voip.ms	reply to pandora The issue isn't "if" the aux heat will kick in with the heat pumps running, it's "when". Heatpumps must defrost the outdoor unit every so often when it's cold. This can be triggered via a mechanical timer or an ice sensor. Sometimes they need to defrost every 30 minutes. During the defrost cycle, the compressor reverse cycles and the indoor heat strips will come on (they have to). Up until now, things have been hunky-dory. It's 20 degrees outside. The generator has been running about 40 minutes. You're snuggled up with the wifey sipping brandy and laughing at the neighbors - then suddenly the generator bogs down and the lights start to flicker... This is the point where you got screwed by your electrician: You have to anticipate the compressor AND the heat strips running simultaneously. Going off the manufacturers cut sheet, your 4 ton unit is going to be drawing about 3.8 kW (avg), and require a minimum heat strip of 10 kW (unfortunately it looks like it might actually need a 12.5 - 15 kW for an effective defrost call from the HP). Throw 2 of these units into the mix and you see the problem... right? 13.8 kW x 2 = offline genset. Even if you only run one of the units, it leaves you very little wiggle room for all of your other household needs (lighting, computers, pumps, TV's, etc...). Your generator probably won't cut it at 20 kW. If you have gas fire instead of electric heat strips, you can see how that rectifies the situation. I think your electrician probably failed to take this into consideration. -- If someone refers to herself / himself as a "guru", they probably aren't.
	to forum · permalink · 2012-09-23 23:59:29 ·
Mr Matt join:2008-01-29 Eustis, FL kudos:1 Reviews: ·CenturyLink ·Comcast ·Embarq Now Centu..	reply to pandora There is one other work around that would be more expensive then heat strips but less expensive then separate gas hot air furnaces. I saw this system in operation and it is very effective. The method below is the only method I could use to heat my home with propane because the air handlers are in half closets on the second floor and the building codes do not permit installation of a gas furnace in that location. I am aware that you already replaced your hot water system, if you did not the cost of the installation would be lower. You can provide auxiliary heat and hot water with a 75 Gallon quick recovery propane fueled hot water heater (75,000 Btu burner). The hot water output of the water heater would be connected to two potable water circulating pumps to circulate hot water, to a water to air heat exchanger in each air handler of the heat pumps and a tempering valve set at 125 degrees to provide domestic hot water. The auxiliary heat relay in the heat pump would turn on the circulating pump feeding the heat exchanger when auxiliary heat is required. In order to provide sufficient heat the water heater would have to be set between 160 and 180 degrees when heat is required. In order to prevent scalding the tempering valve is used to reduce 160 to 180 degree hot water to 125 degrees for domestic use. During the summer the water heater can be set to 125 degrees and only set in the 160 to 180 range in the winter while heat is required. This method is very cost effective if replacing the hot water heater, because the only extra cost is the tempering valve, circulating pumps, heat exchangers and the cost of installation.
	to forum · permalink · 2012-09-24 01:59:28 ·
pandora Premium join:2001-06-01 Outland kudos:1 Reviews: ·Google Voice ·Comcast ·ooma ·Future Nine Corp..	reply to nunya said by nunya: T Up until now, things have been hunky-dory. It's 20 degrees outside. The generator has been running about 40 minutes. You're snuggled up with the wifey sipping brandy and laughing at the neighbors - then suddenly the generator bogs down and the lights start to flicker... This is the point where you got screwed by your electrician: You have to anticipate the compressor AND the heat strips running simultaneously. I shall see what happens and report back. If eating of crow is necessary, then I shall dine upon it, while investigating a propane furnace. -- "People demand freedom of speech as a compensation for the freedom of thought which they seldom use."
	to forum · permalink · 2012-09-24 09:06:32 ·

cowboyro join:2000-10-11 Shelton, CT Reviews: ·AT&T U-Verse	reply to pandora said by pandora: The likelihood the strips will be used for any length of time is near zero. Actually the likelihood is 100%. Defrost cycles occur whenever the heat pumps detect a loss in performance due to icing. That means even above-freezing temperatures with enough humidity. If they don't defrost they will try defrosting over and over and your system will blow cold air. If I'm not too busy I'll post some hard numbers from my system later...
	to forum · permalink · 2012-09-24 09:10:09 ·
cowboyro join:2000-10-11 Shelton, CT Reviews: ·AT&T U-Verse	reply to pandora said by pandora: I shall see what happens and report back. If eating of crow is necessary, then I shall dine upon it, while investigating a propane furnace. A propane-fired tankless heater + hydrocoils probably costs less than the difference between a big-ass generator and a smaller one that has no issue running on emergency heat.
	to forum · permalink · 2012-09-24 09:14:09 ·
Mr Matt join:2008-01-29 Eustis, FL kudos:1 Reviews: ·CenturyLink ·Comcast ·Embarq Now Centu..	I found this website that offers an assortment of hydrocoils: »www.altheatsupply.com/shop-by-ne···ers.html I wonder if a tankless water heater would be able to supply sufficient heat. My Brother In Law used a quick recovery storage type water heater with a 75,000 BTU burner like this one: »www.lowes.com/pd_89263-135-G2F75···cetInfo= It heated a home office in his attic and provided hot water to a collocated bathroom. His costs were different because he used natural gas for heat.
	to forum · permalink · 2012-09-24 09:40:22 ·

Technical > Home Improvement > Anyone have a suggestion for standby whole home generator?

Re: Anyone have a suggestion for standby whole home generator?