Space heaters to run off generator help

[Razorhunter]

Does anyone make a decent ceramic or oil filled heater that is not some new age digital junk with motion sensors, remote controls and all that other garbage? I definitely need heaters that run off standard dirty generator power, meaning they don’t require a sine wave inverter. These would be used for heating a room and possibly even this small house when power goes out and temps drop into the teens. I just want to find something worth buying.

As for the oil filled type, I don’t know where to start. It seems they all have tons of good reviews but then I get paranoid and focus on all the negative Amazon reviews. I hate even looking for this type stuff on Amazon. I’d rather have something old school but that may not be the route I can take. May have to buy new and in stock. What do you suggest for ceramic or oil filled emergency heaters to run off generators?

 

[WildBill]

I couldn't buy an oil filled one when I was looking because of all the bad and scary reviews on seemingly every brand. How big of heater are you looking for? I have some cheap little 1500w ceramic "dumb" heaters plus a large infrared heater that all work fine on a really crappy old generator, none of them care about the power at all.

 

[alwaysFlOoReD]

Look at the wattage. 1500 watts is 1500 watts doesn't matter the size or price of the unit.

 

[nadogail]

Incandescent light bulbs were pretty good at converting electricity into heat. They were also very accepting of low quality power.
I used the “past tense” because in my community they have been replaced by more efficient LED lighting.

 

[Razorhunter]

Look at the wattage. 1500 watts is 1500 watts doesn't matter the size or price of the unit.

Yes I’m aware Sir. And I’m not really having sizing or power requirement issues.

 

[Razorhunter]

Guys I’m just trying to obtain the best equipment I possibly can to stay warm for a period of several days up to even a week when the power goes out. I don’t have a wood burning stove or other fuel/gas source. All I’ve got is gasoline and standard generators. If there is a better way, I’m all ears, but for now, I was just trying to find what ceramic and oil filled heaters to buy. I appreciate everyone’s input on this matter.

 

[PCustoms]

Guys I’m just trying to obtain the best equipment I possibly can to stay warm for a period of several days up to even a week when the power goes out. I don’t have a wood burning stove or other fuel/gas source.

What heats the house when the power is on?

 

[mike93lx]

I haven't used it in a few years, but my duraheat euh5000 has always worked well when I've needed it. A simple switch and a dial thermostat

Why aren't you looking to keep your primary heat source running instead, especially if you don't have an issue with power requirements?

 

[Razorhunter]

What heats the house when the power is on?

A standard heat pump. I’m not sure I’m able to find a big enough generator to push it though. I see guys online talking about a 5kw or 7kw generator handling the startup amps of their HVAC but I always thought you had to have a bigger 12kw+ generator to handle the inrush current based on my calculations. If anyone here has an HVAC running off their 5kw or 7kw generator I’m all ears. I think mine is on either a 50a or 60a breaker. Haven’t measured the inrush current on it yet.

 

[mike93lx]

A standard heat pump. I’m not sure I’m able to find a big enough generator to push it though. I see guys online talking about a 5kw or 7kw generator handling the startup amps of their HVAC but I always thought you had to have a bigger 12kw+ generator to handle the inrush current based on my calculations. If anyone here has an HVAC running off their 5kw or 7kw generator I’m all ears. I think mine is on either a 50a or 60a breaker. Haven’t measured the inrush current on it yet.

Soft start is what you need.

I can start my 2.5ton heat pump on a 5.5kw inverter generator.

But if you have a 50-60a breaker, that likely means a 5 ton... That isn't running on a 7kw

You'll need a soft start with a pretty much any generator if it really is 5 ton.

Post the nameplate, please

Measuring inrush requires a special meter that you almost certainly don't have. You can't do it with a normal clamp meter

 

[larry_g]

I think what your looking for is a milk parlor heater. https://www.google.com/search?q=mil...MAiAYBkAYIkgcDMi40oAf5HQ&sclient=gws-wiz-serp

I've got a couple of these that are years old and use for room heaters when necessary.

lg

 

[jblnut]

I have purchased a few oil filled heaters from Walmart over the years and they’ve all been just fine. None of them have crazy controls, just a knob that can go from 1-10 and two switches to pick voltage.

Looking through their website again there are far more oil filled heaters without digital controls than ones with them.

Here is the same brand as what I’ve been using but with slightly different controls.

Walmart Heater !!

Edit: Larry made another great recommendation with the milk house style heater. I have two in my well house that can kick on if the temps drop too low. I used them to heat it full time before running my wood boiler lines through it a few years ago. Worked great.

 

[Razorhunter]

Soft start is what you need.

I can start my 2.5ton heat pump on a 5.5kw inverter generator.

But if you have a 50-60a breaker, that likely means a 5 ton... That isn't running on a 7kw

You'll need a soft start with a pretty much any generator if it really is 5 ton.

Post the nameplate, please

Measuring inrush requires a special meter that you almost certainly don't have. You can't do it with a normal clamp

Mike, thanks for your help here.
I’ve got all the Fluke meters brother. No problems there. If I recall, my HVAC buddy once told me I have a 3.5 ton unit. It’s actually undersized for this little 1500sq ft house. It fries the capacitor every August and I have to replace said capacitor yearly. I am almost certain it’s not a 5 ton. I will post the nameplate here shortly but I just went out and measured current.

INRUSH 75.5amps

HEATER RUNNING: 8amps

That 75.5 is what gives me concern obviously.

I’d love for a 7000w Honda generator to somehow magically cover this but I am doubtful.


Second question: even if I do manage to get a generator large enough to handle this compressor startup, how do I know if I have an HVAC unit that requires clean pure sine wave power or one that does not? I’ve read that some HVAC units do in fact require some wave inverter generators. Not sure how to determine if this is a need or not?

 

[Razorhunter]

Mike93lx,
Not sure what this forum is doing with my replies but let me try this again.


I’ve got all the Fluke meters brother. No problems there. If I recall, my HVAC buddy once told me I have a 3.5 ton unit. It’s actually undersized for this little 1500sq ft house. It fries the capacitor every August and I have to replace said capacitor yearly. I am almost certain it’s not a 5 ton. I will post the nameplate here shortly but I just went out and measured current.

INRUSH 75.5amps

HEATER RUNNING: 8amps

That 75.5 is what gives me concern obviously.

I’d love for a 7000w Honda generator to somehow magically cover this but I just fail to see how guys are running any typical AC unit off a 7000w generator let alone a 5000w. It mean 7000w only produces 30a at 240v. So what am I missing here? I’m sure some guys are actually meaning they can run little mini split systems but as for a typical HVAC unit, even a 2.5 ton unit, I just don’t see how. Unless they’re doing some type of soft start system, which is something I’ve not dealt with personally.


Second question: even if I do manage to get a generator large enough to handle this compressor startup, how do I know if I have an HVAC unit that requires clean pure sine wave power or one that does not? I’ve read that some HVAC units do in fact require sine wave inverter generators. Not sure how to determine if my unit contains sensitive electronics or if this is a need or not?

 

[rmanrman]

I have two oil filled electric 120V heaters
They are over 10 years old and work great ,
They have a mechanical thermostat but are slow to get up to full heat output
In my family room I have a 800 watt infrared circular heater has only on or off control used while watching tv bought at Walmart heats quickly and it’s quite.

 

[mike93lx]

Mike93lx,
Not sure what this forum is doing with my replies but let me try this again.


I’ve got all the Fluke meters brother. No problems there. If I recall, my HVAC buddy once told me I have a 3.5 ton unit. It’s actually undersized for this little 1500sq ft house. It fries the capacitor every August and I have to replace said capacitor yearly. I am almost certain it’s not a 5 ton. I will post the nameplate here shortly but I just went out and measured current.

INRUSH 75.5amps

HEATER RUNNING: 8amps

That 75.5 is what gives me concern obviously.

I’d love for a 7000w Honda generator to somehow magically cover this but I just fail to see how guys are running any typical AC unit off a 7000w generator let alone a 5000w. It mean 7000w only produces 30a at 240v. So what am I missing here? I’m sure some guys are actually meaning they can run little mini split systems but as for a typical HVAC unit, even a 2.5 ton unit, I just don’t see how. Unless they’re doing some type of soft start system, which is something I’ve not dealt with personally.


Second question: even if I do manage to get a generator large enough to handle this compressor startup, how do I know if I have an HVAC unit that requires clean pure sine wave power or one that does not? I’ve read that some HVAC units do in fact require sine wave inverter generators. Not sure how to determine if my unit contains sensitive electronics or if this is a need or not?

A soft start will do it

Micro-Air EasyStart Flex Residential Soft Starter

EasyStart Flex Soft Starter, the most advanced, versatile, and one-size-fits-all residential HVAC soft starter, works with AC units up to 6 tons

invertersrus.com

 

[PCustoms]

Unless I'm missing something how are a few 1500W heaters off a generator going to keep the house warm for several days when the current 3.5 ton system is undersized?

 

[Razorhunter]

Unless I'm missing something how are a few 1500W heaters off a generator going to keep the house warm for several days when the current 3.5 ton system is undersized?

The thought here would be I would just be trying to not die basically and heat a single bedroom until I can one day obtain a generator and fuel storage containers large enough to run the central HVAC.
Btw, The existing unit is slightly undersized but not terribly. It just pops the cap every year or two.

Regardless, as I said, I would just be needing to keep the bedroom at a comfortable enough temp to sleep as comfortably as possible.

 

[mike93lx]

The thought here would be I would just be trying to not die basically and heat a single bedroom until I can one day obtain a generator and fuel storage containers large enough to run the central HVAC.
Btw, The existing unit is slightly undersized but not terribly. It just pops the cap every year or two.

Regardless, as I said, I would just be needing to keep the bedroom at a comfortable enough temp to sleep as comfortably as possible.

Why would the unit sizing impact cap life?

 

[PCustoms]

Why would the unit sizing impact cap life?

Was thinking the same thing, when I decided it made no sense you had already posted

 

[dcg9381]

I run space heaters all the time off generators (RV use).
Standard resistance heat units work just fine. For an RV I prefer one that isn't loud... They're pretty dead simple.

For an "oil filled" heater, I've got one of those too.. As far as I can tell it's totally analog.



I've run these off of:
Champion 2500i generator
Champion 3500 generator (non-inverter)
Champion 3500i dual fuel generator.


For the house (back up heat) I installed propane drops and use Mr. Buddy space heaters. I have propane two drops in the house (I installed "Ts" off the water heater and stove area. A 30K BTU unit put downstairs will keep the house above 70 degrees even when it's in the 10-20 degree F outside.

Second question: even if I do manage to get a generator large enough to handle this compressor startup, how do I know if I have an HVAC unit that requires clean pure sine wave power or one that does not? I’ve read that some HVAC units do in fact require sine wave inverter generators. Not sure how to determine if my unit contains sensitive electronics or if this is a need or not?

The compressor start up is "helped" substantially by those "soft start" kits. RV AC units have high start up draw also, so I put soft starts on them. I can do a 13.5K BTU heat pump (12A continuous) with a 2500 watt generator.

As far as I know ALL of the "whole house" generators (we have a 20kW genset) are not inverter generators. They do just fine with my heat pumps, but even at 20kW, when they kick into emergency heat, they pull a TON of power. When it's cold enough for emergency heat, I simply switch to the Mr. Buddy units.

 

[jblnut]

I run space heaters all the time off generators (RV use).
Standard resistance heat units work just fine. For an RV I prefer one that isn't loud... They're pretty dead simple.

For an "oil filled" heater, I've got one of those too.. As far as I can tell it's totally analog.



I've run these off of:
Champion 2500i generator
Champion 3500 generator (non-inverter)
Champion 3500i dual fuel generator.


For the house (back up heat) I installed propane drops and use Mr. Buddy space heaters. I have propane two drops in the house (I installed "Ts" off the water heater and stove area. A 30K BTU unit put downstairs will keep the house above 70 degrees even when it's in the 10-20 degree F outside.






The compressor start up is "helped" substantially by those "soft start" kits. RV AC units have high start up draw also, so I put soft starts on them. I can do a 13.5K BTU heat pump (12A continuous) with a 2500 watt generator.

As far as I know ALL of the "whole house" generators (we have a 20kW genset) are not inverter generators. They do just fine with my heat pumps, but even at 20kW, when they kick into emergency heat, they pull a TON of power. When it's cold enough for emergency heat, I simply switch to the Mr. Buddy units.

With any nonvented heater one must use extreme caution running it inside ….. they also throw a ton of moisture in the air.

OP: not sure if you have a tractor but another option would be a tractor with a PTO generator. I have a 50kw unit that I use behind an 85hp tractor to run my entire farm when the power goes out. When I lived in town I had a Farmall H that ran a 18kw genny when the power was out. It worked very well and ran anything we’d want in the house. (Gas dryer and range at the time)

I know you said you didn’t have a wood stove but they are fantastic sources of backup heat. Maybe get a wood stove for the home and leave the doors open all over the house so the heat can wander where it may. It’d be a great way to offset some of your regular heating bill as well.

 

[dcg9381]

With any nonvented heater one must use extreme caution running it inside ….. they also throw a ton of moisture in the air.

They definitely add moisture. These were purchased as a "powerless" backup (we had a week of 20 degrees and no power in 2021). They will eventually put moisture on the windows downstairs, but in the event of a total prolonged power outage, they can prevent serious damage to the house caused by pipe breakage...

I know you said you didn’t have a wood stove but they are fantastic sources of backup heat. Maybe get a wood stove for the home and leave the doors open all over the house so the heat can wander where it may. It’d be a great way to offset some of your regular heating bill as well.

Wood stoves with blowers are great.. as long as they are well sealed. But venting them in an existing home can be a little challenging. And they assume you have a wood source. Propane makes more sense for us as we have a 500 gallon tank.

 

[Razorhunter]

Why would the unit sizing impact cap life?

That I cannot tell you. I can repair these things but I’m not an HVAC tech. Basically I had an HVAC tech tell me that if it’s popping the cap yearly then it’s likely because it’s slightly undersized. Take that FWIW I suppose.

 

[mike93lx]

That I cannot tell you. I can repair these things but I’m not an HVAC tech. Basically I had an HVAC tech tell me that if it’s popping the cap yearly then it’s likely because it’s slightly undersized. Take that FWIW I suppose.

Undersized would mean it is struggling to cool the space. Perfectly sized means it runs constantly on the hottest day. I think the cap popping is a symptom of another issue

Are you buying the same caps each year?

 

[BillK]

I didnt read all of the responses but I have two of these units from Home Depot that I have used to keep an unheated warehouse unit above freezing. I have left them running unattended for a week at a time and have never had a problem. They are about as simple as you can get.

5120 BTUs Forced Air Electric Milkhouse Utility Furnace with Thermostat BNS-15DM2 - The Home Depot

Keep your living space warm with the selection of this wonderful Unbranded Forced Air Electric Milkhouse Utility Furnace with Thermostat.

www.homedepot.com

 

[larry4406]

My opinion - Don't use vent free gas heaters. Just don't.

When you read the instructions carefully, most say to open a window to allow combustion air in (so it provides combustion air to the heater and it also dilutes the CO the heater dumps into the home which can kill you.....). The moisture dumped into the home is not good.

We use propane construction heaters at the day job to temper homes to complete finishes and I detest them.

 

[mike93lx]

The moisture dumped into the home is not good.

CO aside, many people spend a lot of money running humidifiers (including me) all winter. A little extra moisture would be welcome

 

[Firstram]

CO aside, many people spend a lot of money running humidifiers (including me) all winter. A little extra moisture would be welcome

An extremely dry house during the heating season is a symptom of air leaking. Think about having a Blower Door Test done.

 

[mike93lx]

An extremely dry house during the heating season is a symptom of air leaking. Think about having a Blower Door Test done.

I know... And then thousands in sealing and insulation, at least

 

[rct]

Electric heat is very power intensive. Project Farm on youtube recently reviewed diesel heaters. Might be worth a look. I'd also consider wood or pellet stoves, or a diesel drip heater. Fans and ignitors use much less electricity during operation.

 

[American Locomotive]

Just get one of the milkhouse heaters like BillK mentioned. They're cheap and work pretty well.

One thing that's worth mentioning is that space heaters running off a generator will absolutely plow fuel. Running two 1500 watt space heaters off a ~7kW generator will require close to 15 gallons of gas per day.

 

[PCustoms]

I'm still trying to wrap my head around all this.

I've got a 24k mini split, which is 2 tons per Google, for 1300sqft. I've used it for years down to around freezing, forget what it's rated to

How the heck is the OP running 3.5 tons?

Is his house super leaky/inefficient?

If so, running 10 of those 1500W heaters isn't going to do much....

I think the HVAC needs a service from a competent tech (not salesman) and a soft start along with a generator may be the solution.

 

[mike93lx]

I'm still trying to wrap my head around all this.

I've got a 24k mini split, which is 2 tons per Google, for 1300sqft. I've used it for years down to around freezing, forget what it's rated to

How the heck is the OP running 3.5 tons?

Is his house super leaky/inefficient?

If so, running 10 of those 1500W heaters isn't going to do much....

I think the HVAC needs a service from a competent tech (not salesman) and a soft start along with a generator may be the solution.

Did I miss a location for the OP? Your 1300 ft in Vermont is a bit different than the south

 

[PCustoms]

Did I miss a location for the OP? Your 1300 ft in Vermont is a bit different than the south

Well he talked about temp in the teens and heating, so....

 

[Mike007]

Just get one of the milkhouse heaters like BillK mentioned. They're cheap and work pretty well.

One thing that's worth mentioning is that space heaters running off a generator will absolutely plow fuel. Running two 1500 watt space heaters off a ~7kW generator will require close to 15 gallons of gas per day.

Those little cheap heaters work great. As far as plowing fuel, I did a little experiment. I ran 3, thats 4500 watts +/- 15K Btus off my 8K watt NG generator. I clocked my gas meter. Its the equivalent of burning 110K BTUs of natural gas to net 15K. Definitely wasteful.

 

[Firstram]

I know... And then thousands in sealing and insulation, at least

There‘s a lot you can do to draft stop on the cheap.

 

[Bert_]

For the house (back up heat) I installed propane drops and use Mr. Buddy space heaters. I have propane two drops in the house (I installed "Ts" off the water heater and stove area. A 30K BTU unit put downstairs will keep the house above 70 degrees even when it's in the 10-20 degree F outside.

Exactly what I was thinking.

These aren't what I would want to heat with full time but the other posts are blowing it way out of proportion.

They DON'T emit carbon monoxide when they are working correctly. Carbon monoxide is a result of incomplete combustion. You should have a CO detector though. They DO consume oxygen inside the house. Most all the new ones have a low oxygen sensor. A window cracked open can solve this issue.

Moisture in the house really isn't a big deal for temporary use.

In the house I grew up in, we had one on the living room wall. It was used all winter.

 

[mike93lx]

Well he talked about temp in the teens and heating, so....

Fair

 

[theoldwizard1]

I definitely need heaters that run off standard dirty generator power, meaning they don’t require a sine wave inverter. These would be used for heating a room and possibly even this small house when power goes out and temps drop into the teens. I just want to find something worth buying.

With a small amount of electrical knowledge, you can run a standard home furnace off of non-inverter generator.

I stood over my daughter, supervising her, while she wired a plug on to her furnace. The furnace had electronic controls and an electronic thermostat. It worked perfectly !


Segue : Non-inverter generator get a bad rap about "dirty power". Sure you do NOT want to plug a load in until it has run for the first few minutes of starting (except maybe an incandescent light bulb or an old fashion "milk house" heater).

The one type of generator that DOES produce crappy power is a brushless generator. Stay far away from them.