Stopping the hot air

I have a question about stopping the hot air from coming through my vents during the summer time.

I did some searching on this site and I like the idea of putting a ball valve on the coolant line flowing to the heater core. But can the restriction in coolant flowing through the heater damage the core or have any affect on other parts of my coolant system:?

Thanks in advance for your help fellas,

Allan

 

most of the manufacturers have been doing just this since the mid 80's give or take a few years. they just call them water valves. heater cores are doing ok, mostly the water valves leak before the heater core. hth.