Should one leave the Tanis plugged in for winter?

[pwnel]

Going into my first winter (hangared in NJ) since buying the 231.   I won't be flying much over Dec - Feb and want to do the best for my engine. 

Mike Busch says "using an insulated cover and a multipoint preheating system that is plugged in continuously is one of the most effective methods of eliminating internal engine corrosion, particularly if the aircraft is kept in an unheated hangar rather than outdoors"  ("Engines", p.255)

Continental on the other hand specifically has a warning in the engine manual against doing this.  According to Mike, their concern is moisture evaporating from the oil sump and settling on cool components like camshaft, crankshaft etc.  He says this is unlikely to occur though if the engine is heated with a multipoint system like a Tanis and is covered with an insulated engine cover.

Any Mooney-specific experience and advice here folks?  

[Raptor05121]

I'm a Florida native, so I have no dog in this fight, but from the musings I see on the many type-groups I'm in on FB, someone posted that Tanis themselves warned not to leave it plugged in continuously for the same reason. Just my $0.02. Hope it helps your search.

[amillet]

I’ve been leaving mine plugged in. Tanis says it’s OK as well.  With insulating cover over the cowl the entire engine compartment and engine stay comfortably warm.

From FAQ on Tanis website Yes, Tanis preheat systems can be plugged in continuously.

[steingar]

The short answer is definitely. Put in your cowl plugs, cover the nose with moving blankets and your engine will be a nice toasty 75 degrees all winter. Would you keep your airplane in a heated hangar all winter? Of course! With the Tanis you can make your engine bay into a small heated enclosure.

[toto]

Has anyone had problems with critters during the winter (when an engine heater is always on)?

I have a heater from aircraftheaters.com, and one of my original reasons for buying it was thinking that I could leave it on all the time. But I got nervous, thinking that it would attract mice. 

I've never actually had a mouse problem, and there isn't much edible in the hangar. But a continuously-warm spot seems like it would be attractive to rodents. 

[warren.huisman]

It seems this has been discussed many times with different opinions.  I'm gonna watch this one because it seems logical to me to use a heater all of the time as long as a cowl blanket is used.  

Edited November 11, 2018 by warren.huisman

[steingar]

I’ve used my aircratheaters.com heater for two winters. No mice that I’ve seen. If they nest in a warm place they need to eat. I don’t keep munchies in my hangar.

[carusoam]

Pluses and minuses....

• The heater people assure there is no problem leaving it on... but they didn’t mention corrosion either...
• what improves corrosion’s rate of destruction... moisture and warmth...
• Some heaters are good at heating one area of the engine and not the other...

Since moisture is always present from combustion by-products..

• venting the moisture is important...
• heating the whole engine above the dew point of the air... hard to make happen reliably...
• Ventilating with dry air... could be helpful...

Remember, the point of a pre-heater is to warm the engine...

Its nice to know, that it is safe to leave heated, from a flammability point of view or other heat related damages....

 

I am more of a fan of... heat the day before use, open the oil fill cap after flight allowing steam to escape... allow to be cool or cold for the rest of the time...

It takes a lot of thought and execution to make heating a solution to moisture in the engine... heat the whole engine, vent the whole engine, all the time....

PP thoughts only, not a mechanic or HVAC engineer...

Best regards,

-a-

[larryb]

I leave mine on year-round, with one additional detail. A thermostat set at 90 degrees. I figure 90 is not too hot to deteriorate anything long-term. I know it's a lot hotter during flight, but not 24/7. The main detail is that warm air holds more water in suspension than cool air. So, for a given quantity of water in the engine, a warmer engine will have a lower RH.  I did some experiments with a humidity meter and found significant reduction in RH keeping the engine at 90.

Larry

[DXB]

So I just started leaving mine plugged in all the time, and I leave the oil cap off to help moisture vent from the sump.   I have a Reiff Turbo XP that heats the sump and the cylinders.  After temps in the 30s last night, my CHTs this am upon turning on the engine monitor were in the 70s-80s, and my oil temp read in the 90s F.  With this kind of setup, I have a very hard time seeing how one could get condensation in the engine when the entire engine is so far above ambient temp all the time.  However my physics understanding sucks so I may easily be proven wrong.

[toto]

Fwiw, the aircraftheaters.com product heats the whole engine compartment and keeps it at something like 60 degrees. (I think it actually turns on automatically at 50 and turns off at 70.)

 

[Danb]

I don’t have a preheater on my. Bravo, but from 1990 to 2005 I left my J plugged in all winter with no apparent issues.

[Cruiser]

3 hours ago, DXB said:

So I just started leaving mine plugged in all the time, and I leave the oil cap off to help moisture vent from the sump.   I have a Reiff Turbo XP that heats the sump and the cylinders.  After temps in the 30s last night, my CHTs this am upon turning on the engine monitor were in the 70s-80s, and my oil temp read in the 90s F.  With this kind of setup, I have a very hard time seeing how one could get condensation in the engine when the entire engine is so far above ambient temp all the time.  However my physics understanding sucks so I may easily be proven wrong.

from the weather chapter training we learn that clouds form when the warm, moisture laden air cools to the dew point. This is why all the bases seem to be at the same altitude on stable days.

So, your internal engine parts are a happy 90°F at the surrounding humidity level and suddenly the outside temp drops significantly. The outside of the aluminum engine is cooled from the surrounding air to some new temperature. As long as this differential does not drop below the dew point you should be ok, otherwise moisture will form on the warm side of the cooling metal.Just like it does on the windows and doors in your house.

[larryb]

That is where the old quilt over the engine compartment comes in to play. Everything under the quilt is within a few degrees.

[Rick Junkin]

Another option is to put a WiFi Hotspot device in your hangar, and use a WiFi switching device to enable you to remotely select to power your heating system only when you need it. I use Kasa WiFi receptacles plugged into a power strip in my hangar to allow me to control my engine heater and a couple of battery chargers that I like to leave plugged in when I leave the hangar, but don't necessarily want to leave on all of the time.

Cheers,
Rick

[toto]

29 minutes ago, Junkman said:

Another option is to put a WiFi Hotspot device in your hangar, and use a WiFi switching device to enable you to remotely select to power your heating system only when you need it. I use Kasa WiFi receptacles plugged into a power strip in my hangar to allow me to control my engine heater and a couple of battery chargers that I like to leave plugged in when I leave the hangar, but don't necessarily want to leave on all of the time.

Cheers,
Rick

This. 

I bought a FreedomPop hotspot for about 20 bucks, and it costs zero dollars a month for 500M. Which is way more data than you need to flip a switch on and off. 

 

[LANCECASPER]

This might be a possibility      https://www.sportys.com/pilotshop/thermo-cube-for-heater-35-degree-f-set.html

[amillet]

From Tanis FAQ:

Resistance heat cannot create moisture. Moisture is always present inside your engine and specifically within your oil.  Use of our system will NOT result in corrosion because a Tanis preheat system keeps all of the metal parts that are above the oil level above “dew point” and as a result condensation cannot occur on these parts. Tanis preheat systems are not to be cycled on and off as this could cause the engine to go through “dew point” (timers and thermostats are not to be used).

[steingar]

Again, if someone offered you a heater hangar all winter would you say “no, that might promote corrosion”? 

[neilpilot]

10 hours ago, LANCECASPER said:

This might be a possibility      https://www.sportys.com/pilotshop/thermo-cube-for-heater-35-degree-f-set.html

or get the non-aircraft version at Amazon, for 40% less

 

[LANCECASPER]

3 minutes ago, neilpilot said:

or get the non-aircraft version at Amazon, for 40% less

 

Good point!     https://www.amazon.com/Farm-Innovators-TC-3-Thermostatically-Controlled/dp/B0006U2HD2/ref=sr_1_1?ie=UTF8&qid=1542033825&sr=8-1&keywords=thermocube

[pwnel]

9 hours ago, amillet said:

From Tanis FAQ:

Resistance heat cannot create moisture. Moisture is always present inside your engine and specifically within your oil.  Use of our system will NOT result in corrosion because a Tanis preheat system keeps all of the metal parts that are above the oil level above “dew point” and as a result condensation cannot occur on these parts. Tanis preheat systems are not to be cycled on and off as this could cause the engine to go through “dew point” (timers and thermostats are not to be used).

Thanks folks.  It seems between Tanis themselves and Mike Busch the consensus is to just leave it on under the blanket.  

I was thinking about remote switches too, but it seems this is just unnecessary.  

Edited November 12, 2018 by pwnel

[carusoam]

That Tanis note is terrible...

Written by the same guy that said cam corrosion doesn’t happen...

They should have given another few sentences regarding venting, and insulation and surrounding temps... the MS topics found in this thread...

They went with electric heat doesn’t create moisture... no kidding?

If it did, Einstein would have been all wrong.

Its a technical device. It is OK to supply the technical reasons a customer needs to buy the device...

They selected technical non-sense as a sales technique...

I would be inclined to buy from their competitor instead... because matter can neither be created or destroyed... 

Sorry if this makes your choice more difficult... find a technical friend at the airport near you... see what they are using.

Best regards,

-a-

[Marauder]

Thanks folks.  It seems between Tanis themselves and Mike Busch the consensus is to just leave it on under the blanket.  
I was thinking about remote switches too, but it seems this is just unnecessary.  

My concern would be that keeping it warm all the time without finding a way to dispose of the moisture would lead to a green house effect. Just opening the oil dip tube and hoping the engine vent would be enough to allow moisture out is wishful thinking. If they said, “used with a desiccant flow system”, I’d be more prone to think that will be a good approach.

And keeping the engine warm all the time and not flying it still leaves the concern of oil migrating off of the cam and other parts.




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[mooniac15u]

45 minutes ago, Marauder said:

 

My concern would be that keeping it warm all the time without finding a way to dispose of the moisture would lead to a green house effect. Just opening the oil dip tube and hoping the engine vent would be enough to allow moisture out is wishful thinking. If they said, “used with a desiccant flow system”, I’d be more prone to think that will be a good approach.

And keeping the engine warm all the time and not flying it still leaves the concern of oil migrating off of the cam and other parts.




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Do you have these same concerns when the OAT is 70 degrees?  If the engine is held at a relatively constant temperature (including the surrounding air in the engine compartment) how would the outcome be different?