Heater Control Valve & AC Performance

[Tnice17]

I deleted the heater control valve to help have more room for my custom down pipe, was a winter project. Just recently i noted in 80 degree days the AC performance is pretty low. After driving on the highway i get vent temps of about 50 degrees.

Does anyone know if there is hot coolant running through the heater core at all times, will the AC performance decrease?

Whenever i searched for info on the heater control valve delete, the main topic was how to do it. Topic of AC was not even mentioned in relationship to this valve. Any info would help out!

Thanks!

 

[Enraged]

not sure, but you could quickly test it if you simply loop the lines, removing the heater core from the circuit.

 

[Tnice17]

I was thinking about doing that. I was hoping to find the answer before I spilled any coolant [emoji37]


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[MichiganLC]

I suspect flowing hot coolant behind your blowers would affect the temperature of your incoming air.


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[Tnice17]

I would to, however the flap door for the temp is designed to direct air flow based on command on the HVAC controls. correct? so this shouldn't be a factor, atleast to my knowledge.

 

[bestsupraever]

Hi, with no control to direct the heater valve, it will be always open. So yes hot coolant will be flowing through the core. The blend door is supposed to adjust the cool warm flow ratio according to controll setting. It is possible that the blend door is not sealing 100%, allowing some hot air into the mix even if set at max cool. Set the controls to recirculate, for max cool. It is also possible that your refrigerant level is not as it should be. If you are still running r12 and the sight glass shows clear at 1500 rpm's then the refrig level is good. If there are a lot of bubbles, then ref needs to be added. If you are running r134, the sight glass is meaningless as a judge of proper ref level. And if you are running r134 and the condenser, and expansion valve haven' t been changed to be more compatible with r134, the system will not be as efficient as the old r12 system was, and not achieve as cold a vent temp on hotter days.
Also if you loop the water valve out of the system, your defrosting action will not be sufficient under humid conditions.
Luck. Semper Fi

 

[Nick M]

Does anyone know if there is hot coolant running through the heater core at all times, will the AC performance decrease?

Of course it does. That is why the valve was installed at the factory. It was not installed to make manufacturing costs higher.

I would to, however the flap door for the temp is designed to direct air flow based on command on the HVAC controls. correct? so this shouldn't be a factor, atleast to my knowledge.

Take a look at the layout.

Even with the door closed so air is not forced over the heater core, the heater core is still inside the box at 200 degrees, heating the air as it goes by. The valve restricts but does not block flow, greatly reducing the temperature of the heater core.

Also, 50 degree discharge temp with ambient temps across America's heartland about 95 with humidity is acceptable.

 

[jetjock]

^ What he said. The purpose of the valve is to block coolant flow to the core (although even when closed it's designed to allow a tiny bit through) when the climate control system is set to 65 degrees. Based on tests I did years ago not having it will cost you around 10 degrees of cooling performance.

 

[SupraBro]

Great info guys, learned a little bit myself here

 

[Tnice17]

^ What he said. The purpose of the valve is to block coolant flow to the core (although even when closed it's designed to allow a tiny bit through) when the climate control system is set to 65 degrees. Based on tests I did years ago not having it will cost you around 10 degrees of cooling performance.

exactly the type of answer i was looking for. thank you!

Glad this also helped you out to SupraBro.