Posted by Don K on November 28, 2007, 9:10 pm
> Don K wrote:
>>
>>> The radiator type are the safest. The heat is the most comfortable.
>>
>>
>> Comfortable? Not for me.
>>
>> My in-laws had one of those quartz radiant heaters and I remember
>> I'd be warm on one side and cold on the other.
> And if you were outside with that then at least half of yourself would be warm.
> But no one is recommending a quartz tube heater. The radiant area is too
small and the
> temperature is too high. You need surface area. Note "radiator", not "radiant".
The term radiator is ambiguous in this context.
Oil-filled heaters heat mostly by convection but I guess people
still like to call them radiators because they look like those
old-fashioned "radiators" that connected to hot water or steam pipes.
Don
Posted by nicksanspam on November 29, 2007, 6:18 am
>Oil-filled heaters heat mostly by convection but I guess people
>still like to call them radiators because they look like those
>old-fashioned "radiators" that connected to hot water or steam pipes.
Some call them radiators because they mostly radiate vs convect, even
with low surface temps :-) A 2'-tall 80 F 1 ft^2 vertical surface in
a 70 F room convects 0.19(80-70)^(4/3) = 4 Btu/h, in turbulent flow.
It radiates 0.1714x10^-8((460+80)^4-(460+70)^4) = 10 Btu/h.
Nick
Posted by Don K on November 29, 2007, 7:20 am
>>Oil-filled heaters heat mostly by convection but I guess people
>>still like to call them radiators because they look like those
>>old-fashioned "radiators" that connected to hot water or steam pipes.
> Some call them radiators because they mostly radiate vs convect, even
> with low surface temps :-) A 2'-tall 80 F 1 ft^2 vertical surface in
> a 70 F room convects 0.19(80-70)^(4/3) = 4 Btu/h, in turbulent flow.
> It radiates 0.1714x10^-8((460+80)^4-(460+70)^4) = 10 Btu/h.
That's surprising!
Posted by Jeff on November 29, 2007, 11:04 am
Don K wrote:
>
>>
>>
>>>Oil-filled heaters heat mostly by convection but I guess people
>>>still like to call them radiators because they look like those
>>>old-fashioned "radiators" that connected to hot water or steam pipes.
>>
>>Some call them radiators because they mostly radiate vs convect, even
>>with low surface temps :-) A 2'-tall 80 F 1 ft^2 vertical surface in
>>a 70 F room convects 0.19(80-70)^(4/3) = 4 Btu/h, in turbulent flow.
>>It radiates 0.1714x10^-8((460+80)^4-(460+70)^4) = 10 Btu/h.
>
>
> That's surprising!
>
>
Note the 4th power. If you knew that before you wouldn't have been
surprised!
Jeff
Posted by WaterBoy on November 29, 2007, 2:35 pm
.
Consumer Reports, Oct 2007
has an article/ratings on space heaters
you might want to read
waterboy
XML site map
>>
>>> The radiator type are the safest. The heat is the most comfortable.
>>
>>
>> Comfortable? Not for me.
>>
>> My in-laws had one of those quartz radiant heaters and I remember
>> I'd be warm on one side and cold on the other.
> And if you were outside with that then at least half of yourself would be warm.
> But no one is recommending a quartz tube heater. The radiant area is too