Cat vs IR

[ArtStream]

Catalytic heater-vs- Infrared.

I've been shopping for a propane heater for my 28'.
As you might know, the standard catalytic heaters, both the Wave and Olympic range in price from $300 to $500 bucks.

I found a propane wall mounted infrared heater with a 5-10,000 btu output, USA made for $175. It measures 7x21x13.

I've been told conflicting things about IR. One is that it will not heat a room, just the person standing in front of it, on the other hand, "it will heat a xx' X xx' room?"

My question for the Airforum sperts is, would an 10,000BTU IR heater in my 28" make give me the same toasty affect as the vastly more pricey Cat?



Michael

[uwe]

Here an explanation on how catalytic heaters work. This is from teh company that make the only "safe" catalytic heaters, it is supplied with fresh air and does not deplete the oxygen inside the trailer when in use. It also comes with a wall thermostat.

It sounds like the process of heating is similar than IR.

http://www.ventedcatheater.com/6.html


Here some information on infrared heat:

Infrared heater - Wikipedia, the free encyclopedia

[2airishuman]

hey michael, are you planning to go where it gets cold!

the platinum cat uwe linked is the ONLY way to go.

world's safest catalytic heater bro!

i've mentioned this company in other catalytic threads, it's a great product.

it's the best and safest unit because of the fresh air venting, and the company is small but responsive to user needs.

nearly 20 trouble free years with my last one.

the warmth we humans and dogs feel from these radiant cats is sublime...

yet objects are relatively unaffected. that's one of the reasons they can be surface mounted safely, with wood or upholstery nearby.

with your skills, you'd have no trouble doing the custom install and venting...

they DO increase significantly the moisture/water content of the indoor environment

so lots more condensation has to be addressed especially if used for long periods...

they are a little more $$ but you're worth it!

cheers
2air'

[bryanl]

The page for the vented catalytic heater says all combustion products are vented - seems to be a powered vent at less than a half amp draw. It also uses 5 amps for 2 minutes to get the catalyst up to temperature. I think some other use an open flame to get things started.

If it is fully vented, it shouldn't contribute to the humidity as the water vapor is a combustion byproduct. But I hear that the venting isn't as complete as that of, say, the furnace because the combustion still takes place in the target area.

A catalytic _is_ a propane fired infra red heating device. The big feature of the catalytic is that its burn temperature is very low and very efficient. I think the standard propane infrared is probably using standard combustion.

Infrared heaters heat space by heating things in front of them that then heat other things by conduction or convection. The catalytic heaters may not get as hot as an open flame heater but you still need to watch out for anything combustible too close in front of them.

Combustion heating sources in the under 20k BTU/hour range are often available for use without venting. Your oven and stove are examples. There is also an instant hot water heater in this range that isn't vented. The assumption is that the room is large enough and well enough vented so as to minimize combustion problems with health and safety.

At least I think this is the case - let me know if not, please!

As far as safety - you did hear about the family that had the roof vents open but still succumbed to their catalytic heater recently? You do need to take appropriate measures to be sure that oxygen isn't depleted and combustion gases don't build up. Make sure your smoke, gas, and CO alarms are functional, too.

[2airishuman]

hi bryan

stoves, ovens and range tops do have vents and a 2 speed fan overhead.

the plat cat does vent all gases, but water is heavier and thicker than the others so it doesn't exit completely.

i can verify that water remains just like the shower/vent arrangement.

the plat cat comes with separate vent screens and hose and can be vented creatively like behind the fridge or furncace heat door or water heater door or dirctly thought he skin.

my experence with a unit about the same size as art's, i needed 2 cats...

one in the main galley/living area and one in back bed room....

this made the bed toasty!

cheers
2air'

[overlander63]

When I first saw the thread title I thought we were comparing Caterpillar to Ingersoll-Rand...
I like our cat heater better, but I have had more experience with that than the infrared ones. Our dog likes cats, too...

[bryanl]

thanks Joe

the plat cat does vent all gases, but water is heavier and thicker than the others so it doesn't exit completely.

that makes sense. but is also puts emphasis on the fact that its combustion is in the living space. (CO and CO2 are also rather 'heavy' gases which is why these gas detectors should be places low)

That makes the 'vented' catalytic claims seem to be more of a marketing gimmick than a reality.

stoves, ovens and range tops do have vents and a 2 speed fan overhead.

but that vent isn't there for combustion gases.

And this is a contrast to the furnace which has the combustion chamber sealed from the interior.

my experence with a unit about the same size as art's, i needed 2 cats...

can't help but think "what does the dog think of this?" - but then a nice warm IR source is something most dogs can really appreciate.

and, besides cats (and dogs), now we have caterpillars. oh my. the trailer is getting crowded.

There there is the RV Hydronic Heating System viewpoint on this that is also interesting. But one advantage, at least in terms of energy use, of the catalytic is that it is a space heater and only puts heat where its most needed.

[Chuck]

Originally Posted by Leipper

As far as safety - you did hear about the family that had the roof vents open but still succumbed to their catalytic heater recently? You do need to take appropriate measures to be sure that oxygen isn't depleted and combustion gases don't build up. Make sure your smoke, gas, and CO alarms are functional, too.

No, I didn't. I DID hear of a family that suffocated from a "PROPANE HEATER". The news article that was posted here did not specify whether or not it was a catalytic heater, and I sincerely doubt that it was. "propane heater" could be anything. (this was the family in the horse trailer?)

Newer cats are available w/ O2 sensors that'll shut themselves down if the O2 gets too low. If it isn't too low, the heater will not produce a measureable amount of CO.
My old one throws out a ton of heat. Too much, most of the time...even on its very lowest setting. (no thermostat. but the plus side to that is: no electricity required). I have to look at it from the opposite angle. Not "will this keep me warm enough?", but rather "Is it cold enough so that running this thing won't roast me out of the trailer?". But my trailer is on the short-side, at 23'. you can't get that far away from it. We can't let it run all night, though, but not for "safety" concerns; With 3 of us, someone is always on the front gaucho, right in front of the heater, and its just too much heat for whoever is there. When there were only 2 of us, and we slept on the bunks, it kept us comfortable all night, without roasting us.

Oh, and my gas stove in my house doesn't have any sort of venting, nor is there any code requirement for it to be. It simply doesn't put out enough CO to be considered a hazzard.

[2airishuman]

Originally Posted by Leipper

...That makes the 'vented' catalytic claims seem to be more of a marketing gimmick than a reality...

hi bryan

the plat cats used early on by many of the a/s dealers doing this mod only had the 'fresh air' venting feature.

market gimick? perhaps but it is the ONLY one approved (by who?) for rv application.

and with the fresh air venting installed correctly, there is no need to open windows.

i realize the range vent in our trailers isn't there for co, i was thinking about moisture from cooking, like the shower/vent analogy.

it is also possible that the extra condensation i experienced had something to do with spending more time inside the unit.

longer nights sleeping, less patio time, both add to insensible human/dog water loss inside....

cheers
2air'

[Foureagles]

I use an Olympian Wave 6 as primary heat (furnace is busted) in my '71 27' Overlander where I live full-time. As a radiant device, it mainly heats surfaces within line-o'-sight, and long ago warped the cabinet doors it faces across the kitchen. Here in Upstate South C'lina, where it seldom drops below 20 degrees F, it's been able to maintain indoor temperatures somewhat above 40 degrees on the coldest night while burning around a gallon per day.

My CO sensor seems to work (can trigger it with a cigarette held close), and trial & error (ain't woke up dead yet) suggests that this old trailer can't seal tightly enough to cause a problem -- at least so far.

If you use any sort of radiant heat, Cat/IR functioning essentially the same, just point it at yourself for decent comfort. A swivel mount might be a good idea. Of course, plumbing is almost entirely unprotected when using such a setup without warm air streaming through the ductwork.

[bryanl]

It simply doesn't put out enough CO to be considered a hazzard.

I worry about 'misinterpreting' this. The living space combustion at under 20k BTU/hr being OK rule of thumb is for typical home type spaces. An RV is quite confined in comparison. (see link for hydronic above for discussion by someone sensitive to combustion products)

O2 sensors are nice and so are CO detectors but they are not foolproof. The catalytic process burns very efficiently and that reduces risk from combustion products, too. The vented cat is definitely better than non vented and reduces risk further.

But still, we loose people every year because something went wrong.

I think we need to be very careful in how we might minimize hazards so as not to believe our own predelictions improperly. This is one area where we don't want laxity in procedures, I think.

(I don't advocate following those who will not use any propane based heating at all, though. That seems to be a bit towards an excess paranoia.)

longer nights sleeping, less patio time, both add to insensible human/dog water loss inside....

Inside winter humidity is an interesting topic on its own. You sure get reminded of just how much perspiration and respiration create the need to keep the fluids replenished - reminds me I oughta go get that a cup of hot ...

Then there is the 100 watts of heat produced by a typical human. I'd guess a large dog could add another 50 watts or more. Not much compared to the kilowatt or so of heat from a space heater but it does add up.

If I get my basic chem right, a gallon of propane should produce about a bit less than a gallon of water as a combustion product. That represents 93k BTU of heat or about 10 -15 hours with the typical catalytic heater? So about 2 gallons per day to the humidity from a catalytic plus maybe a half gallon per day per human plus the vapors from that hot toddy - nowhere for it to go so it adds up. (I guess we could calculate the humidity change from adiabatic heating plus contributed moisture plus volume plus whatever, too, and then the condensation rate based on a model of the skin temperatures but some other time ;-) )

[ArtStream]

Thanks to all for your input

I think I might just add some extra batteries and continue with the furnance.

I said "might"

Michael

[pmclemore]

2air,

Where did you mount the one in the front?

Thanks - Pat.

[2airishuman]

hi pat

the forward plat cat in the moho was curb side mounted just inside the main door facing forward....

on the lower cabinetry wall.

venting was through the existing fridge? access door where the gas line was also available...

it did a great job of warming the living area and pooch bed...

cheers
2air'

[Frank's Trailer Works]

I was thinking of going with a cat heater in the rear and one in the front. We will most likely not be camping when it is super cold, but want the family comfortable on a early spring morning. I read about warping if cabinets.... is this something to worry about in terms or placement? Is that the Infra red heater that does that? I cannot see anywhere a cat heater could be mounted in a trailer that would have a clear line of site. Has anyone had these warping issues?

[pmclemore]

Originally Posted by 2airishuman

hi pat

the forward plat cat in the moho was curb side mounted just inside the main door facing forward....

on the lower cabinetry wall.

venting was through the existing fridge? access door where the gas line was also available...

it did a great job of warming the living area and pooch bed...

cheers
2air'

Old thread, but I'm finally getting off the dime. When you vented to the refrig compartment, did you have to attach something to the grille (to the outside), or did you just vent into the compartment?

Thanks - Pat

[2airishuman]

Originally Posted by pmclemore

Old thread, but I'm finally getting off the dime. When you vented to the refrig compartment, did you have to attach something to the grille (to the outside), or did you just vent into the compartment?

Thanks - Pat

into the compartment only and then INTO the flooring of the compartment for direct outside air...

clearly having 2 vents (high/low) for the fridge or a fan is useful here...

the plat/cat used to come with a pleasant looking round chrome? vent covers ...

so that IF the ducting goes directly to the exterior skin it looks good.

they may still have models/styles with 2 vent options (fresh and exhaust)...

i haven't checked with them in a while...

cheers
2air'