Best 20 Amp 240 volt Heater for 24x40

[PDXCummins]

I have searched the forum and scroured the internet but have been unable to find a decisive answer. I have a 24x40 insulated pole barn I am attempting to heat as best as I can. Due to many reasons my only heating option is electric and I am limited to a 20 amp circuit. I realize this is not ideal but that’s my current situation. What similar heaters have people used with good results? The two I have narrowed it down to are the following the Cadet RCP402S The Hot One and the Dimplex DHWH4031G Garage and Shop. The specification and reviews are similar but the Cadet is almost twice as expensive. I’m hoping someone can shine share some first hand experiences so I can make the best purchase possible. Thanks for all the help.

 

[c39er]

With your limitations you might be able to heat a 10' by 10' office.

 

[PDXCummins]

Yes I stated in my OP the situation was not ideal but it is what it is. I’m trying to find the best solution possible given the limitations in provided.

 

[3rdgendslmech]

You might be better off with a 80 or 100K btu torpedo heater

 

[alwaysFlOoReD]

The other responders should just answer the question.

Without having any experience I would just go with the cheaper one.

 

[PDXCummins]

That’s kind of the direction I am leaning. I’m going to buy them off of Amazon so if I’m not happy with the cheaper one I can easily return it and try the other one. Unless someone says the more spendy Cadet is worth the extra money.

 

[outdoorspace]

I also have an insulated 24x40 shop. My 24k heat pump draws 9A. They generate 2-3x the heat for the same power as a resistive heater.

 

[log man]

Bingo - heat pump. More expensive up front but 2-4 times more heat per watt.

 

[flash_e_gt]

Any thoughts on the cadet?

 

[Falcon67]

Well - I can heat my 24x40 8' ceiling, insulated with this 240v G73 Dayton.

BUT - it pulls 21A @ 5000w and requires 10 gauge wire. So heat pump is about your only option. Or a 4000w heater which will struggle to do anything. Assuming 16A is good on a 20A circuit.

 

[dcg9381]

Bingo - heat pump. More expensive up front but 2-4 times more heat per watt.

True, but the OP is in Oregon. Heat pump isn't going to be worth a darn when it gets really, really cold. It'll work well above freezing, but performance is going to drop pretty fast when it's really cold.

Electrical resistance heat is pretty much all the same - he just needs to find a heater that operates within the limits of his 20A circuit (16A continuous).

 

[rlitman]

True, but the OP is in Oregon. Heat pump isn't going to be worth a darn when it gets really, really cold. It'll work well above freezing, but performance is going to drop pretty fast when it's really cold...

Not true, unless we're talking about arctic temperatures*. Down at 0F, any modern heat pump will still put out more heat than a resistance heater drawing the same current. Yes, they need to be derated with lower capacity in the cold (some more than others), but that doesn't mean they stop entirely.

*And looking at plant hardiness maps, Oregon varies from zone 9 anywhere near the coast (that's the same as most of South Carolina) to as low as zone 6b farthest inland (same as Ohio). None of that is outside of a heat pump's operating range. If he's in one of the high elevation zone 4b areas, then yeah, that heat pump isn't going to be working much at -25F.

Remember that planting zones are based on the coldest potential days to expect. That temperature might be expected to be reached one or two days a decade, and heating system design temperatures tend to be a little higher.

Also, for 95% of the heating season, the temperature will be considerably higher, and at 20F, a good heat pump should put out 3x as much heat as the resistance heater.

 

[bottom feeder]

Well - I can heat my 24x40 8' ceiling, insulated with this 240v G73 Dayton.

BUT - it pulls 21A @ 5000w and requires 10 gauge wire. So heat pump is about your only option. Or a 4000w heater which will struggle to do anything. Assuming 16A is good on a 20A circuit.

The OP has probably made his choice by now, but for future reference the Dayton/Fahrenheat heaters (manufactured by Marley) have internal jumpers that allow for a wide array of wattage draws. See page 3 of the installation manual:

https://images.homedepot-static.com/catalog/pdfImages/7d/7df676e6-e676-41d9-8701-2e9db3018544.pdf

 

[ForceFed70]

Not true, unless we're talking about arctic temperatures*. Down at 0F, any modern heat pump will still put out more heat than a resistance heater drawing the same current. Yes, they need to be derated with lower capacity in the cold (some more than others), but that doesn't mean they stop entirely.

Your typical heat pump switches over to backup heat source at +20*F
https://asm-air.com/heat-pump/what-temperature-is-a-heat-pump-not-effective/

There are specialty heat pumps made for cold weather climates. They are very expensive. And even they don't typically operate below 0*F although I did find one company that advertises -4*F. At 0*F this heat pump would be only marginally more efficient than electric resistance heat.
https://www.nordicghp.com/2017/01/heat-pump-effective-temperature-range/

OP: Too many people overlook baseboard heaters. They're cheap, quiet, and effective. Might want to consider one.

 

[rpcraft]

Good insulation may be the key to getting the most efficiency out of limited device but there are limits to what even that can do. Is the place well insulated already, if not then you are going to be fighting an uphill battle?

 

[justinjoyal]

Your typical heat pump switches over to backup heat source at +20*F
https://asm-air.com/heat-pump/what-temperature-is-a-heat-pump-not-effective/

There are specialty heat pumps made for cold weather climates. They are very expensive. And even they don't typically operate below 0*F although I did find one company that advertises -4*F. At 0*F this heat pump would be only marginally more efficient than electric resistance heat.
https://www.nordicghp.com/2017/01/heat-pump-effective-temperature-range/

So very NOT true.

Even the cheapest mini-splits will provide a fair amount of heat until ~0F.

The best ones have impressive output even below -25F.

But in the case of OP the cheapest electric heater is probably the best bet.

 

[greenskeeper]

OP are you planning to maintain a minimum temperature or only heat while you are out working in the barn?

The reason I ask is if you are only heating while working I'd suggest getting an over-sized or the largest heater you can afford to throw lots of heat to warm the unheated space in a decent amount of time.

Is a used oil fired forced air furnace not an option? Around here people are literally giving them away as they switch to gas.

 

[clappr]

I have a 30x38 garage, and heat it with a ventless off the shelf radiant heater. It kept me toasty warm when it was 15F here in Michigan. The brand was Dynaglow. 30000 btu.

 

[boblikestools]

I have a 4000W 240v Dimplex heater in my 16 x 20 garage. Works great.

 

[Falcon67]

>Even the cheapest mini-splits will provide a fair amount of heat until ~0F.

Our house heat pump runs a lot when it gets 20 and below, but still heats. No problem. The only time E-heat comes on would be if the t-stat setting and the interior temp delta more than 5F. Because I programmed it that way.