A/C question

Does it hurt to run an air conditioner in the winter with the heat valve turned up on high? Wondering about tractors and a heat pump for home heating and cooling.

I don't know that it hurts the AC or not, but...many times in the road-trucks (Semi's), we had to turn on the AC WITH heat, to dry moisture from the windows..never seemed to hurt a thing..
No need to have it on for more than a couple minutes, tho..

Ron..

Ain"t got a clue, except...........when I run the defroster in my pickup, the compressor runs.

It used to be recommended to run them periodically during the winter to move oil up to keep the seals in condition.

Bushhog, we have to do that sometimes in combine cabs. It means it's time to clean the wet junk out of the evaporator compartment and blow out the drains. A combine AC system pulls in a whole lot more junk than a truck does but eventually a truck evaporator can get dirty too. Jim

Always seemed to mmake breathing easier so i ran it constontly in winter . Just adjusted temperature accordingly.157000 miles last year i drove full time.Never hurt thing.

Most AC units run when ever the defrost is on, therefore most of the winter!

Sounds like your asking the same question about two different things as a tractor A/C and heat system is different than a heat pump type system.

With a mobile system there are two different coils in the system, one tied to the engine coolant system for heat, and the second one is part of the A/C system and does the cooling.

Given the complexity/size of a heat pump system there is simply too much equipment involved to operate a mobile system, like you'd find on a typical vehicle, as a heat pump. In a vehicle application such as this, it's much easier to use two seperate coils. Additionaly they can get more BTU's of heat, and get it faster, regardless of the outside temp, from the engine coolant system than they could from a heat pump system. Given that it typically takes more BTU's of heat to bring an area up to a comfortable temp range on a really cold day than it does to bring it down to a comfortable temp on a hot day it just plain out works better to use the heat from the engine to do the heating than it does to engineer a heat pump system to do the same thing in the given space.

As for the operation of a true heat pump, it works exactly the same way whether it's acting as an A/C or as a heater, the only difference is that the flow of gasses is reversed. Basically you are either pumping heat out of an area to the 'outside' or pumping heat from the 'outside' and into the same area. A typical heat pump system can obtain about a 30 degree differential between the 'input' and the 'output' air temps. In other words on a 30 degree day your output into the climate controlled area would typically be something like 60 degrees, max, or 70 degrees on a 100 degree day. Granted 60 degrees isn't cold but for most people it's not exactly a comfortable temp without a lite jacket, but around 70 is considered to feel pretty good by most. That's why a heat pump system also uses electric heat strips to add heat to the air going back into the room and 'make up the difference' the heat pump system can't supply, and help warm the area to a more comfortable temp when outside temps are near or below freezing.

With those explinations, and given the way your question was asked, here's an answer to your question. In a mobile vehicle it's not gonna hurt anything at all to have the A/C on along with the heat. Like other posts have stated, on most modern vehicles, with an A/C system, the A/C actually kicks on anytime you turn on the defroster, wether the heat is also on or not. This happens because the heater only warms the air, but the operation of the A/C also dehumidifies it. Given that the heater has a higher BTU output than the A/C this means that if you turn on the heat the air blowing on the window to defrost it isn't just warm, it's also dry... and dry air just works better to remove moisture from a fogged up window.

So, a more direct answer your question about the A/C working along with the heat in a tractor/vehicle, the answer is NO, it's not gonna hurt a thing.

Now, as far as a home heat pump system goes, unless you rewire some interlocks, the electric heat strips will not work when your system is in cooling mode. Due to the way the main system itself works it can't heat and cool at the same time by itself because the gas can only flow in one direction at a time. So, in the case of a home heat pump system the direct answer is this. The heat and cool of the heat pump itself can not work at the same time. However if you were to rewire things and turn the electric heat strips on then the complete system would theoretically be heating and cooling at the same time. In that case, just as in the case of a vehicle system, it's not gonna hurt anything except that the heat pump system would just have to work harder to remove the heat being thrown back into the system from the electric heat strips.

That's alot longer answer/explination than what your question was but given the way the question was asked I figured the only real answer had to explain why things happened, didn't happem, or couldn't happen like you asked..... or it wouldn't be a real answer.........

Most automotive air conditioners will not run below about 45 degrees F, no matter how you set the controls. And as others have posted, it's good to run the A/C in conjunction with the heater to reduce humidity in the vehicle. Which is why most modern cars automatically turn on the A/C when the heater is set to defrost. Many run the A/C all the time, regardless of the heater setting, as long as the temperature is warm enough to avoid evaporator icing.

And as Wayne explained, a home heat pump is either heating or cooling; it can't do both simultaneously.

Auto air conditioner should be run periodically, to keep seals from drying out, etc.- but that happens automatically (when defroster is working), so you don't have to worry about it.

Home heat pump- As Wayne said below, heating and cooling is exactly the same except flow of coolant is reversed. So no advantage of trying to get it to cool in winter, because the machinery is all being operated regardless of the mode. Oh, and yes, you can get it to cool in winter- jack up the thermostat to about 80, then move the cool lever down to 72, and it will start blowing cold air. But no point in doing that.

A lot of autos run the A/C every time the defrost is on.