Atmos machine update

Takes a pass at updating ATMOSPHERICS to take advantage of the new powernet changes.

Also removes var/on definitions from many atmos machines. Machines generally shouldn't
be doing "on" things if they aren't using power, and most players don't expect a machine
to use power if it isn't "on," so I guess this is fair game.

Also, further refactoring.

code/ATMOSPHERICS/_atmospherics_helpers.dm

@@ -9,6 +9,7 @@
 
 
 /obj/machinery/atmospherics/var/last_flow_rate = 0
+/obj/machinery/atmospherics/var/last_power_draw = 0
 /obj/machinery/portable_atmospherics/var/last_flow_rate = 0
 
 
@@ -390,21 +391,13 @@
 
 	return specific_power
 
-//This proc handles power usages.
-//Calling update_use_power() or use_power() too often will result in lag since updating area power can be costly.
-//This proc implements an approximation scheme that will cause area power updates to be triggered less often.
-//By having atmos machinery use this proc it is easy to change the power usage approximation for all atmos machines
-/obj/machinery/proc/handle_power_draw(var/usage_amount)
-	//This code errs on the side of using more power. Using this will mean that sometimes atmos machines use more power than they need, but won't get power for free.
-	if (usage_amount > idle_power_usage)
-		update_use_power(2)
-	else
-		if (use_power >= 2)
-			use_power = 1	//Don't update here. We will use more power than we are supposed to, but trigger less area power updates.
-		else
-			update_use_power(1)
-
-	switch (use_power)
-		if (0) return 0
-		if (1) return idle_power_usage
-		if (2 to INFINITY) return max(idle_power_usage, usage_amount)
+//Calculates the APPROXIMATE amount of moles that would need to be transferred to change the pressure of sink by pressure_delta
+//If set, sink_volume_mod adjusts the effective output volume used in the calculation. This is useful when the output gas_mixture is 
+//part of a pipenetwork, and so it's volume isn't representative of the actual volume since the gas will be shared across the pipenetwork when it processes.
+/proc/calculate_transfer_moles(datum/gas_mixture/source, datum/gas_mixture/sink, var/pressure_delta, var/sink_volume_mod=0)
+	//Make the approximation that the sink temperature is unchanged after transferring gas
+	var/air_temperature = (sink.temperature > 0)? sink.temperature : source.temperature
+	var/output_volume = (sink.volume * sink.group_multiplier) + sink_volume_mod
+		
+	//get the number of moles that would have to be transfered to bring sink to the target pressure
+	return pressure_delta*output_volume/(air_temperature * R_IDEAL_GAS_EQUATION)

code/ATMOSPHERICS/atmospherics.dm

@@ -15,6 +15,7 @@ Pipelines + Other Objects -> Pipe network
 	active_power_usage = 0
 	power_channel = ENVIRON
 	var/nodealert = 0
+	var/power_rating //the maximum amount of power the machine can use to do work, affects how powerful the machine is, in Watts
 
 	layer = 2.4 //under wires with their 2.44
 

code/ATMOSPHERICS/components/binary_devices/dp_vent_pump.dm

@@ -22,14 +22,12 @@
 
 	level = 1
 
-	use_power = 1
+	use_power = 0
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 7500	//This also doubles as a measure of how powerful the pump is, in Watts. 7500 W ~ 10 HP
-	var/last_power_draw = 0
+	power_rating = 7500			//7500 W ~ 10 HP
 
 	connect_types = CONNECT_TYPE_REGULAR|CONNECT_TYPE_SUPPLY|CONNECT_TYPE_SCRUBBER //connects to regular, supply and scrubbers pipes
 
-	var/on = 0
 	var/pump_direction = 1 //0 = siphoning, 1 = releasing
 
 	var/external_pressure_bound = EXTERNAL_PRESSURE_BOUND
@@ -77,7 +75,7 @@
 	if(!powered())
 		vent_icon += "off"
 	else
-		vent_icon += "[on ? "[pump_direction ? "out" : "in"]" : "off"]"
+		vent_icon += "[use_power ? "[pump_direction ? "out" : "in"]" : "off"]"
 
 	overlays += icon_manager.get_atmos_icon("device", , , vent_icon)
 
@@ -106,10 +104,10 @@
 /obj/machinery/atmospherics/binary/dp_vent_pump/process()
 	..()
 
-	if(stat & (NOPOWER|BROKEN) || !on)
-		update_use_power(0)	//usually we get here because a player turned a pump off - definitely want to update.
-		last_power_draw = 0
-		last_flow_rate = 0
+	last_power_draw = 0
+	last_flow_rate = 0
+
+	if(stat & (NOPOWER|BROKEN) || !use_power)
 		return 0
 
 	var/datum/gas_mixture/environment = loc.return_air()
@@ -122,35 +120,25 @@
 	if(pressure_delta > 0.5)
 		if(pump_direction) //internal -> external
 			if (node1 && (environment.temperature || air1.temperature))
-				var/output_volume = environment.volume * environment.group_multiplier
-				var/air_temperature = environment.temperature? environment.temperature : air1.temperature
-				var/transfer_moles = pressure_delta*output_volume/(air_temperature * R_IDEAL_GAS_EQUATION)
-
-				power_draw = pump_gas(src, air1, environment, transfer_moles, active_power_usage)
+				var/transfer_moles = calculate_transfer_moles(air1, environment)
+				power_draw = pump_gas(src, air1, environment, transfer_moles, power_rating)
 
 				if(power_draw >= 0 && network1)
 					network1.update = 1
 		else //external -> internal
 			if (node2 && (environment.temperature || air2.temperature))
-				var/output_volume = air2.volume + (network2? network2.volume : 0)
-				var/air_temperature = air2.temperature? air2.temperature : environment.temperature
-				var/transfer_moles = pressure_delta*output_volume/(air_temperature * R_IDEAL_GAS_EQUATION)
+				var/transfer_moles = calculate_transfer_moles(environment, air2, (network2)? network2.volume : 0)
 
 				//limit flow rate from turfs
 				transfer_moles = min(transfer_moles, environment.total_moles*air2.volume/environment.volume)	//group_multiplier gets divided out here
-
-				power_draw = pump_gas(src, environment, air2, transfer_moles, active_power_usage)
+				power_draw = pump_gas(src, environment, air2, transfer_moles, power_rating)
 
 				if(power_draw >= 0 && network2)
 					network2.update = 1
 
-	if (power_draw < 0)
-		last_power_draw = 0
-		last_flow_rate = 0
-		//update_use_power(0)
-		use_power = 0	//don't force update - easier on CPU
-	else
-		last_power_draw = handle_power_draw(power_draw)
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
 
 	return 1
 
@@ -191,7 +179,7 @@
 	signal.data = list(
 		"tag" = id,
 		"device" = "ADVP",
-		"power" = on,
+		"power" = use_power,
 		"direction" = pump_direction?("release"):("siphon"),
 		"checks" = pressure_checks,
 		"input" = input_pressure_min,
@@ -223,10 +211,10 @@
 	if(!signal.data["tag"] || (signal.data["tag"] != id) || (signal.data["sigtype"]!="command"))
 		return 0
 	if(signal.data["power"])
-		on = text2num(signal.data["power"])
+		use_power = text2num(signal.data["power"])
 
 	if(signal.data["power_toggle"])
-		on = !on
+		use_power = !use_power
 
 	if(signal.data["direction"])
 		pump_direction = text2num(signal.data["direction"])

code/ATMOSPHERICS/components/binary_devices/passive_gate.dm

@@ -14,7 +14,7 @@
 
 	use_power = 0
 	
-	var/on = 0	//doesn't actually use power. this is just whether the valve is open or not
+	var/unlocked = 0	//If 0, then the valve is locked closed, otherwise it is open(-able, it's a one-way valve so it closes if gas would flow backwards).
 	var/target_pressure = ONE_ATMOSPHERE
 	var/max_pressure_setting = 15000	//kPa
 	var/set_flow_rate = ATMOS_DEFAULT_VOLUME_PUMP * 2.5
@@ -32,7 +32,7 @@
 	air2.volume = ATMOS_DEFAULT_VOLUME_PUMP * 2.5
 
 /obj/machinery/atmospherics/binary/passive_gate/update_icon()
-	icon_state = (on && flowing)? "on" : "off"
+	icon_state = (unlocked && flowing)? "on" : "off"
 
 /obj/machinery/atmospherics/binary/passive_gate/update_underlays()
 	if(..())
@@ -48,8 +48,10 @@
 
 /obj/machinery/atmospherics/binary/passive_gate/process()
 	..()
-	if(!on)
-		last_flow_rate = 0
+	
+	last_flow_rate = 0
+	
+	if(!unlocked)
 		return 0
 
 	var/output_starting_pressure = air2.return_pressure()
@@ -73,30 +75,22 @@
 		//Figure out how much gas to transfer to meet the target pressure.
 		switch (regulate_mode)
 			if (REGULATE_INPUT)
-				var/air_temperature = (air1.temperature > 0)? air1.temperature : air2.temperature
-				var/input_volume = air1.volume + (network1? network1.volume : 0)
-				transfer_moles = min(transfer_moles, pressure_delta*input_volume/(air_temperature * R_IDEAL_GAS_EQUATION))
+				transfer_moles = min(transfer_moles, calculate_transfer_moles(air2, air1, pressure_delta, (network1)? network1.volume : 0))
 			if (REGULATE_OUTPUT)
-				var/air_temperature = (air2.temperature > 0)? air2.temperature : air1.temperature
-				var/output_volume = air2.volume + (network2? network2.volume : 0)
-				
-				transfer_moles = min(transfer_moles, pressure_delta*output_volume/(air_temperature * R_IDEAL_GAS_EQUATION))	
+				transfer_moles = min(transfer_moles, calculate_transfer_moles(air1, air2, pressure_delta, (network2)? network2.volume : 0))
 		
 		//pump_gas() will return a negative number if no flow occurred
 		returnval = pump_gas(src, air1, air2, transfer_moles, available_power=0)	//available_power=0 means we only move gas if it would flow naturally
 	
-	if (returnval < 0)
-		flowing = 0
-		last_flow_rate = 0
-	else
+	if (returnval >= 0)
 		if(network1)
 			network1.update = 1
 
 		if(network2)
 			network2.update = 1
 		
-		if (!last_flow_rate)
-			flowing = 0
+	if (last_flow_rate)
+		flowing = 1
 	
 	update_icon()
 
@@ -120,7 +114,7 @@
 	signal.data = list(
 		"tag" = id,
 		"device" = "AGP",
-		"power" = on,
+		"power" = unlocked,
 		"target_output" = target_pressure,
 		"regulate_mode" = regulate_mode,
 		"set_flow_rate" = set_flow_rate,
@@ -141,10 +135,10 @@
 		return 0
 
 	if("power" in signal.data)
-		on = text2num(signal.data["power"])
+		unlocked = text2num(signal.data["power"])
 
 	if("power_toggle" in signal.data)
-		on = !on
+		unlocked = !unlocked
 
 	if("set_target_pressure" in signal.data)
 		target_pressure = between(
@@ -188,7 +182,7 @@
 	var/data[0]
 	
 	data = list(
-		"on" = on,
+		"on" = unlocked,
 		"pressure_set" = round(target_pressure*100),	//Nano UI can't handle rounded non-integers, apparently.
 		"max_pressure" = max_pressure_setting,
 		"input_pressure" = round(air1.return_pressure()*100),
@@ -213,7 +207,7 @@
 	if(..()) return
 	
 	if(href_list["toggle_valve"])
-		on = !on
+		unlocked = !unlocked
 	
 	if(href_list["regulate_mode"])
 		switch(href_list["regulate_mode"])
@@ -247,7 +241,7 @@
 /obj/machinery/atmospherics/binary/passive_gate/attackby(var/obj/item/weapon/W as obj, var/mob/user as mob)
 	if (!istype(W, /obj/item/weapon/wrench))
 		return ..()
-	if (on)
+	if (unlocked)
 		user << "\red You cannot unwrench this [src], turn it off first."
 		return 1
 	var/datum/gas_mixture/int_air = return_air()

code/ATMOSPHERICS/components/binary_devices/pump.dm

@@ -20,18 +20,16 @@ Thus, the two variables affect pump operation are set in New():
 	name = "gas pump"
 	desc = "A pump"
 
-	var/on = 0
 	var/target_pressure = ONE_ATMOSPHERE
 
 	//var/max_volume_transfer = 10000
 
-	use_power = 1
+	use_power = 0
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 7500	//This also doubles as a measure of how powerful the pump is, in Watts. 7500 W ~ 10 HP
+	power_rating = 7500			//7500 W ~ 10 HP
 
-	var/last_power_draw = 0			//for UI
 	var/max_pressure_setting = 15000	//kPa
-	
+
 	var/frequency = 0
 	var/id = null
 	var/datum/radio_frequency/radio_connection
@@ -43,14 +41,14 @@ Thus, the two variables affect pump operation are set in New():
 
 /obj/machinery/atmospherics/binary/pump/on
 	icon_state = "map_on"
-	on = 1
+	use_power = 1
 
 
 /obj/machinery/atmospherics/binary/pump/update_icon()
 	if(!powered())
 		icon_state = "off"
 	else
-		icon_state = "[on ? "on" : "off"]"
+		icon_state = "[use_power ? "on" : "off"]"
 
 /obj/machinery/atmospherics/binary/pump/update_underlays()
 	if(..())
@@ -65,10 +63,10 @@ Thus, the two variables affect pump operation are set in New():
 	update_underlays()
 
 /obj/machinery/atmospherics/binary/pump/process()
-	if((stat & (NOPOWER|BROKEN)) || !on)
-		update_use_power(0)	//usually we get here because a player turned a pump off - definitely want to update.
-		last_power_draw = 0
-		last_flow_rate = 0
+	last_power_draw = 0
+	last_flow_rate = 0
+
+	if((stat & (NOPOWER|BROKEN)) || !use_power)
 		return
 
 	var/power_draw = -1
@@ -76,22 +74,13 @@ Thus, the two variables affect pump operation are set in New():
 
 	if(pressure_delta > 0.01 && air1.temperature > 0)
 		//Figure out how much gas to transfer to meet the target pressure.
-		var/air_temperature = (air2.temperature > 0)? air2.temperature : air1.temperature
-		var/output_volume = air2.volume + (network2? network2.volume : 0)
-		
-		//get the number of moles that would have to be transfered to bring sink to the target pressure
-		var/transfer_moles = pressure_delta*output_volume/(air_temperature * R_IDEAL_GAS_EQUATION)
-		
-		power_draw = pump_gas(src, air1, air2, transfer_moles, active_power_usage)
-	
-	if (power_draw < 0)
-		//update_use_power(0)
-		use_power = 0	//don't force update - easier on CPU
-		last_power_draw = 0
-		last_flow_rate = 0
-	else
-		last_power_draw = handle_power_draw(power_draw)
-		
+		var/transfer_moles = calculate_transfer_moles(air1, air2, pressure_delta, (network2)? network2.volume : 0)
+		power_draw = pump_gas(src, air1, air2, transfer_moles, power_rating)
+
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
+
 		if(network1)
 			network1.update = 1
 
@@ -119,7 +108,7 @@ Thus, the two variables affect pump operation are set in New():
 	signal.data = list(
 		"tag" = id,
 		"device" = "AGP",
-		"power" = on,
+		"power" = use_power,
 		"target_output" = target_pressure,
 		"sigtype" = "status"
 	)
@@ -134,14 +123,14 @@ Thus, the two variables affect pump operation are set in New():
 
 	// this is the data which will be sent to the ui
 	var/data[0]
-	
+
 	data = list(
-		"on" = on,
+		"on" = use_power,
 		"pressure_set" = round(target_pressure*100),	//Nano UI can't handle rounded non-integers, apparently.
 		"max_pressure" = max_pressure_setting,
 		"last_flow_rate" = round(last_flow_rate*10),
 		"last_power_draw" = round(last_power_draw),
-		"max_power_draw" = active_power_usage,
+		"max_power_draw" = power_rating,
 	)
 
 	// update the ui if it exists, returns null if no ui is passed/found
@@ -152,7 +141,7 @@ Thus, the two variables affect pump operation are set in New():
 		ui = new(user, src, ui_key, "gas_pump.tmpl", name, 470, 290)
 		ui.set_initial_data(data)	// when the ui is first opened this is the data it will use
 		ui.open()					// open the new ui window
-		ui.set_auto_update(1)		// auto update every Master Controller tick
+		ui.set_auto_update(1)		// auto update every Master Controller tick
 
 /obj/machinery/atmospherics/binary/pump/initialize()
 	..()
@@ -165,12 +154,12 @@ Thus, the two variables affect pump operation are set in New():
 
 	if(signal.data["power"])
 		if(text2num(signal.data["power"]))
-			on = 1
+			use_power = 1
 		else
-			on = 0
+			use_power = 0
 
 	if("power_toggle" in signal.data)
-		on = !on
+		use_power = !use_power
 
 	if(signal.data["set_output_pressure"])
 		target_pressure = between(
@@ -190,7 +179,7 @@ Thus, the two variables affect pump operation are set in New():
 	return
 
 /obj/machinery/atmospherics/binary/pump/attack_hand(user as mob)
-	if(..())
+	if(..())
 		return
 	src.add_fingerprint(usr)
 	if(!src.allowed(user))
@@ -201,11 +190,11 @@ Thus, the two variables affect pump operation are set in New():
 	return
 
 /obj/machinery/atmospherics/binary/pump/Topic(href,href_list)
-	if(..()) return
-	
+	if(..()) return
+
 	if(href_list["power"])
-		on = !on
-	
+		use_power = !use_power
+
 	switch(href_list["set_press"])
 		if ("min")
 			target_pressure = 0
@@ -214,10 +203,10 @@ Thus, the two variables affect pump operation are set in New():
 		if ("set")
 			var/new_pressure = input(usr,"Enter new output pressure (0-[max_pressure_setting]kPa)","Pressure control",src.target_pressure) as num
 			src.target_pressure = between(0, new_pressure, max_pressure_setting)
-	
+
 	usr.set_machine(src)
 	src.add_fingerprint(usr)
-	
+
 	src.update_icon()
 
 /obj/machinery/atmospherics/binary/pump/power_change()
@@ -229,7 +218,7 @@ Thus, the two variables affect pump operation are set in New():
 /obj/machinery/atmospherics/binary/pump/attackby(var/obj/item/weapon/W as obj, var/mob/user as mob)
 	if (!istype(W, /obj/item/weapon/wrench))
 		return ..()
-	if (!(stat & NOPOWER) && on)
+	if (!(stat & NOPOWER) && use_power)
 		user << "\red You cannot unwrench this [src], turn it off first."
 		return 1
 	var/datum/gas_mixture/int_air = return_air()
@@ -246,4 +235,4 @@ Thus, the two variables affect pump operation are set in New():
 			"\blue You have unfastened \the [src].", \
 			"You hear ratchet.")
 		new /obj/item/pipe(loc, make_from=src)
-		del(src)
+		del(src)

code/ATMOSPHERICS/components/binary_devices/volume_pump.dm

@@ -6,14 +6,14 @@
 	name = "high power gas pump"
 	desc = "A pump. Has double the power rating of the standard gas pump."
 
-	active_power_usage = 15000	//This also doubles as a measure of how powerful the pump is, in Watts. 15000 W ~ 20 HP
+	power_rating = 15000	//15000 W ~ 20 HP
 
 /obj/machinery/atmospherics/binary/pump/high_power/on
-	on = 1
+	use_power = 1
 	icon_state = "map_on"
 
 /obj/machinery/atmospherics/binary/pump/high_power/update_icon()
 	if(!powered())
 		icon_state = "off"
 	else
-		icon_state = "[on ? "on" : "off"]"
+		icon_state = "[use_power ? "on" : "off"]"

code/ATMOSPHERICS/components/omni_devices/filter.dm

@@ -11,7 +11,7 @@
 
 	use_power = 1
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 7500	//This also doubles as a measure of how powerful the filter is, in Watts. 7500 W ~ 10 HP
+	power_rating = 7500			//7500 W ~ 10 HP
 
 	var/max_flow_rate = 200
 	var/set_flow_rate = 200
@@ -69,14 +69,11 @@
 
 	var/power_draw = -1
 	if (transfer_moles > MINUMUM_MOLES_TO_FILTER)
-		power_draw = filter_gas_multi(src, filtering_outputs, input_air, output_air, transfer_moles, active_power_usage)
+		power_draw = filter_gas_multi(src, filtering_outputs, input_air, output_air, transfer_moles, power_rating)
 
-	if (power_draw < 0)
-		//update_use_power(0)
-		use_power = 0	//don't force update - easier on CPU
-		last_flow_rate = 0
-	else
-		handle_power_draw(power_draw)
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
 
 		if(input.network)
 			input.network.update = 1
@@ -106,7 +103,7 @@
 /obj/machinery/atmospherics/omni/filter/proc/build_uidata()
 	var/list/data = new()
 
-	data["power"] = on
+	data["power"] = use_power
 	data["config"] = configuring
 
 	var/portData[0]
@@ -162,16 +159,16 @@
 	switch(href_list["command"])
 		if("power")
 			if(!configuring)
-				on = !on
+				use_power = !use_power
 			else
-				on = 0
+				use_power = 0
 		if("configure")
 			configuring = !configuring
 			if(configuring)
-				on = 0
+				use_power = 0
 
 	//only allows config changes when in configuring mode ~otherwise you'll get weird pressure stuff going on
-	if(configuring && !on)
+	if(configuring && !use_power)
 		switch(href_list["command"])
 			if("set_flow_rate")
 				var/new_flow_rate = input(usr,"Enter new flow rate limit (0-[max_flow_rate]L/s)","Flow Rate Control",set_flow_rate) as num

code/ATMOSPHERICS/components/omni_devices/mixer.dm

@@ -7,7 +7,7 @@
 
 	use_power = 1
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 3700	//This also doubles as a measure of how powerful the mixer is, in Watts. 3700 W ~ 5 HP
+	power_rating = 3700			//3700 W ~ 5 HP
 
 	var/list/inputs = new()
 	var/datum/omni_port/output
@@ -108,14 +108,11 @@
 
 	var/power_draw = -1
 	if (transfer_moles > MINUMUM_MOLES_TO_FILTER)
-		power_draw = mix_gas(src, mixing_inputs, output.air, transfer_moles, active_power_usage)
+		power_draw = mix_gas(src, mixing_inputs, output.air, transfer_moles, power_rating)
 
-	if (power_draw < 0)
-		//update_use_power(0)
-		use_power = 0	//don't force update - easier on CPU
-		last_flow_rate = 0
-	else
-		handle_power_draw(power_draw)
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
 
 		for(var/datum/omni_port/P in inputs)
 			if(P.concentration && P.network)
@@ -144,7 +141,7 @@
 /obj/machinery/atmospherics/omni/mixer/proc/build_uidata()
 	var/list/data = new()
 
-	data["power"] = on
+	data["power"] = use_power
 	data["config"] = configuring
 
 	var/portData[0]
@@ -180,16 +177,16 @@
 	switch(href_list["command"])
 		if("power")
 			if(!configuring)
-				on = !on
+				use_power = !use_power
 			else
-				on = 0
+				use_power = 0
 		if("configure")
 			configuring = !configuring
 			if(configuring)
-				on = 0
+				use_power = 0
 
 	//only allows config changes when in configuring mode ~otherwise you'll get weird pressure stuff going on
-	if(configuring && !on)
+	if(configuring && !use_power)
 		switch(href_list["command"])
 			if("set_flow_rate")
 				var/new_flow_rate = input(usr,"Enter new flow rate limit (0-[max_flow_rate]L/s)","Flow Rate Control",set_flow_rate) as num

code/ATMOSPHERICS/components/omni_devices/omni_base.dm

@@ -9,7 +9,6 @@
 	initialize_directions = 0
 	level = 1
 
-	var/on = 0
 	var/configuring = 0
 	//var/target_pressure = ONE_ATMOSPHERE	//a base type as abstract as this should NOT be making these kinds of assumptions
 
@@ -53,7 +52,7 @@
 	else if(error_check())
 		overlays = overlays_error
 	else
-		overlays = on ? (overlays_on) : (overlays_off)
+		overlays = use_power ? (overlays_on) : (overlays_off)
 
 	underlays = underlays_current
 
@@ -63,12 +62,13 @@
 	return
 
 /obj/machinery/atmospherics/omni/process()
-	if(error_check())
-		on = 0
+	last_power_draw = 0
+	last_flow_rate = 0
 
-	if((stat & (NOPOWER|BROKEN)) || !on)
-		update_use_power(0)	//usually we get here because a player turned a pump off - definitely want to update.
-		last_flow_rate = 0
+	if(error_check())
+		use_power = 0
+
+	if((stat & (NOPOWER|BROKEN)) || !use_power)
 		return 0
 	return 1
 

code/ATMOSPHERICS/components/trinary_devices/filter.dm

@@ -8,7 +8,7 @@
 
 	use_power = 1
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 7500	//This also doubles as a measure of how powerful the filter is, in Watts. 7500 W ~ 10 HP
+	power_rating = 7500	//This also doubles as a measure of how powerful the filter is, in Watts. 7500 W ~ 10 HP
 
 	var/temp = null // -- TLE
 
@@ -66,10 +66,10 @@
 	if(!powered())
 		icon_state += "off"
 	else if(node2 && node3 && node1)
-		icon_state += on ? "on" : "off"
+		icon_state += use_power ? "on" : "off"
 	else
 		icon_state += "off"
-		on = 0
+		use_power = 0
 
 /obj/machinery/atmospherics/trinary/filter/update_underlays()
 	if(..())
@@ -98,9 +98,11 @@
 
 /obj/machinery/atmospherics/trinary/filter/process()
 	..()
-	if((stat & (NOPOWER|BROKEN)) || !on)
-		update_use_power(0)	//usually we get here because a player turned a pump off - definitely want to update.
-		last_flow_rate = 0
+	
+	last_power_draw = 0
+	last_flow_rate = 0
+	
+	if((stat & (NOPOWER|BROKEN)) || !use_power)
 		return
 
 	//Figure out the amount of moles to transfer
@@ -108,7 +110,7 @@
 
 	var/power_draw = -1
 	if (transfer_moles > MINUMUM_MOLES_TO_FILTER)
-		power_draw = filter_gas(src, filtered_out, air1, air2, air3, transfer_moles, active_power_usage)
+		power_draw = filter_gas(src, filtered_out, air1, air2, air3, transfer_moles, power_rating)
 
 		if(network2)
 			network2.update = 1
@@ -119,12 +121,9 @@
 		if(network1)
 			network1.update = 1
 
-	if (power_draw < 0)
-		//update_use_power(0)
-		use_power = 0	//don't force update - easier on CPU
-		last_flow_rate = 0
-	else
-		handle_power_draw(power_draw)
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
 
 	return 1
 
@@ -179,7 +178,7 @@
 			current_filter_type = "ERROR - Report this bug to the admin, please!"
 
 	dat += {"
-			<b>Power: </b><a href='?src=\ref[src];power=1'>[on?"On":"Off"]</a><br>
+			<b>Power: </b><a href='?src=\ref[src];power=1'>[use_power?"On":"Off"]</a><br>
 			<b>Filtering: </b>[current_filter_type]<br><HR>
 			<h4>Set Filter Type:</h4>
 			<A href='?src=\ref[src];filterset=0'>Phoron</A><BR>
@@ -193,16 +192,7 @@
 			[src.set_flow_rate]L/s | <a href='?src=\ref[src];set_flow_rate=1'>Change</a><BR>
 			<B>Flow rate: </B>[round(last_flow_rate, 0.1)]L/s
 			"}
-/*
-		user << browse("<HEAD><TITLE>[src.name] control</TITLE></HEAD>[dat]","window=atmo_filter")
-		onclose(user, "atmo_filter")
-		return
 
-	if (src.temp)
-		dat = text("<TT>[]</TT><BR><BR><A href='?src=\ref[];temp=1'>Clear Screen</A>", src.temp, src)
-	//else
-	//	src.on != src.on
-*/
 	user << browse("<HEAD><TITLE>[src.name] control</TITLE></HEAD><TT>[dat]</TT>", "window=atmo_filter")
 	onclose(user, "atmo_filter")
 	return
@@ -235,7 +225,7 @@
 		var/new_flow_rate = input(usr,"Enter new flow rate (0-[air1.volume]L/s)","Flow Rate Control",src.set_flow_rate) as num
 		src.set_flow_rate = max(0, min(air1.volume, new_flow_rate))
 	if(href_list["power"])
-		on=!on
+		use_power=!use_power
 	src.update_icon()
 	src.updateUsrDialog()
 /*

code/ATMOSPHERICS/components/trinary_devices/mixer.dm

@@ -8,7 +8,7 @@
 
 	use_power = 1
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 3700	//This also doubles as a measure of how powerful the mixer is, in Watts. 3700 W ~ 5 HP
+	power_rating = 3700	//This also doubles as a measure of how powerful the mixer is, in Watts. 3700 W ~ 5 HP
 
 	var/set_flow_rate = ATMOS_DEFAULT_VOLUME_MIXER
 	var/list/mixing_inputs
@@ -30,10 +30,10 @@
 	if(!powered())
 		icon_state += "off"
 	else if(node2 && node3 && node1)
-		icon_state += on ? "on" : "off"
+		icon_state += use_power ? "on" : "off"
 	else
 		icon_state += "off"
-		on = 0
+		use_power = 0
 
 /obj/machinery/atmospherics/trinary/mixer/update_underlays()
 	if(..())
@@ -68,17 +68,17 @@
 	air1.volume = ATMOS_DEFAULT_VOLUME_MIXER
 	air2.volume = ATMOS_DEFAULT_VOLUME_MIXER
 	air3.volume = ATMOS_DEFAULT_VOLUME_MIXER * 1.5
+	
+	if (!mixing_inputs)
+		mixing_inputs = list(src.air1 = node1_concentration, src.air2 = node2_concentration)
 
 /obj/machinery/atmospherics/trinary/mixer/process()
 	..()
 
-	//For some reason this doesn't work even in initialize(), so it goes here.
-	if (!mixing_inputs)
-		mixing_inputs = list(src.air1 = node1_concentration, src.air2 = node2_concentration)
+	last_power_draw = 0
+	last_flow_rate = 0
 
-	if((stat & (NOPOWER|BROKEN)) || !on)
-		update_use_power(0)	//usually we get here because a player turned a pump off - definitely want to update.
-		last_flow_rate = 0
+	if((stat & (NOPOWER|BROKEN)) || !use_power)
 		return
 
 	//Figure out the amount of moles to transfer
@@ -86,7 +86,7 @@
 
 	var/power_draw = -1
 	if (transfer_moles > MINUMUM_MOLES_TO_FILTER)
-		power_draw = mix_gas(src, mixing_inputs, air3, transfer_moles, active_power_usage)
+		power_draw = mix_gas(src, mixing_inputs, air3, transfer_moles, power_rating)
 
 		if(network1 && mixing_inputs[air1])
 			network1.update = 1
@@ -97,12 +97,9 @@
 		if(network3)
 			network3.update = 1
 
-	if (power_draw < 0)
-		//update_use_power(0)
-		use_power = 0	//don't force update - easier on CPU
-		last_flow_rate = 0
-	else
-		handle_power_draw(power_draw)
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
 
 	return 1
 
@@ -133,7 +130,7 @@
 		user << "\red Access denied."
 		return
 	usr.set_machine(src)
-	var/dat = {"<b>Power: </b><a href='?src=\ref[src];power=1'>[on?"On":"Off"]</a><br>
+	var/dat = {"<b>Power: </b><a href='?src=\ref[src];power=1'>[use_power?"On":"Off"]</a><br>
 				<b>Set Flow Rate Limit: </b>
 				[set_flow_rate]L/s | <a href='?src=\ref[src];set_press=1'>Change</a>
 				<br>
@@ -161,7 +158,7 @@
 /obj/machinery/atmospherics/trinary/mixer/Topic(href,href_list)
 	if(..()) return
 	if(href_list["power"])
-		on = !on
+		use_power = !use_power
 	if(href_list["set_press"])
 		var/max_flow_rate = min(air1.volume, air2.volume)
 		var/new_flow_rate = input(usr,"Enter new flow rate limit (0-[max_flow_rate]L/s)","Flow Rate Control",src.set_flow_rate) as num

code/ATMOSPHERICS/components/trinary_devices/trinary_base.dm

@@ -1,9 +1,7 @@
 obj/machinery/atmospherics/trinary
 	dir = SOUTH
 	initialize_directions = SOUTH|NORTH|WEST
-	use_power = 1
-
-	var/on = 0
+	use_power = 0
 
 	var/datum/gas_mixture/air1
 	var/datum/gas_mixture/air2

code/ATMOSPHERICS/components/unary/cold_sink.dm

@@ -13,12 +13,10 @@
 	var/heatsink_temperature = T20C	//the constant temperature resevoir into which the freezer pumps heat. Probably the hull of the station or something.
 	var/internal_volume = 600	//L
 
-	var/on = 0
 	use_power = 0
 	idle_power_usage = 5			//5 Watts for thermostat related circuitry
-	active_power_usage			//50 kW. The power rating of the freezer
 
-	var/max_power_usage = 20000 //power rating when the usage is turned up to 100
+	var/max_power_rating = 20000 //power rating when the usage is turned up to 100
 	var/power_setting = 100
 
 	var/set_temperature = T20C	//thermostat
@@ -37,7 +35,7 @@
 	component_parts += new /obj/item/weapon/stock_parts/capacitor(src)
 	component_parts += new /obj/item/weapon/stock_parts/manipulator(src)
 
-	active_power_usage = max_power_usage * (power_setting/100)
+	power_rating = max_power_rating * (power_setting/100)
 
 /obj/machinery/atmospherics/unary/freezer/initialize()
 	if(node) return
@@ -54,7 +52,7 @@
 
 /obj/machinery/atmospherics/unary/freezer/update_icon()
 	if(src.node)
-		if(src.on && cooling)
+		if(src.use_power && cooling)
 			icon_state = "freezer_1"
 		else
 			icon_state = "freezer"
@@ -71,7 +69,7 @@
 /obj/machinery/atmospherics/unary/freezer/ui_interact(mob/user, ui_key = "main", var/datum/nanoui/ui = null, var/force_open = 1)
 	// this is the data which will be sent to the ui
 	var/data[0]
-	data["on"] = on ? 1 : 0
+	data["on"] = use_power ? 1 : 0
 	data["gasPressure"] = round(air_contents.return_pressure())
 	data["gasTemperature"] = round(air_contents.temperature)
 	data["minGasTemperature"] = 0
@@ -101,9 +99,8 @@
 
 /obj/machinery/atmospherics/unary/freezer/Topic(href, href_list)
 	if (href_list["toggleStatus"])
-		src.on = !src.on
+		src.use_power = !src.use_power
 		update_icon()
-		update_use_power(on)
 	if(href_list["temp"])
 		var/amount = text2num(href_list["temp"])
 		if(amount > 0)
@@ -119,31 +116,30 @@
 
 /obj/machinery/atmospherics/unary/freezer/process()
 	..()
-	if(stat & (NOPOWER|BROKEN) || !on)
+	if(stat & (NOPOWER|BROKEN) || !use_power)
 		cooling = 0
-		update_use_power(0)
 		update_icon()
 		return
 
 	if (network && air_contents.temperature > set_temperature)
 		cooling = 1
-		update_use_power(2)
 
 		var/heat_transfer = max( -air_contents.get_thermal_energy_change(set_temperature - 5), 0 )
 
 		//Assume the heat is being pumped into the hull which is fixed at heatsink_temperature
 		//not /really/ proper thermodynamics but whatever
 		var/cop = FREEZER_PERF_MULT * air_contents.temperature/heatsink_temperature	//heatpump coefficient of performance from thermodynamics -> power used = heat_transfer/cop
-		heat_transfer = min(heat_transfer, cop * active_power_usage)	//limit heat transfer by available power
+		heat_transfer = min(heat_transfer, cop * power_rating)	//limit heat transfer by available power
 
 		var/removed = -air_contents.add_thermal_energy(-heat_transfer)		//remove the heat
 		if (debug)
 			visible_message("[src]: Removing [removed] W.")
 
+		use_power(power_rating)
+
 		network.update = 1
 	else
 		cooling = 0
-		update_use_power(1)
 
 	update_icon()
 
@@ -171,14 +167,14 @@
 	bin_rating /= bin_count
 	manip_rating /= manip_count
 
-	active_power_usage = initial(active_power_usage)*cap_rating			//more powerful
+	power_rating = initial(power_rating)*cap_rating			//more powerful
 	heatsink_temperature = initial(heatsink_temperature)/((manip_rating+bin_rating)/2)	//more efficient
 	air_contents.volume = max(initial(internal_volume) - 200, 0) + 200*bin_rating
 	set_power_level(power_setting)
 
 /obj/machinery/atmospherics/unary/freezer/proc/set_power_level(var/new_power_setting)
 	power_setting = new_power_setting
-	active_power_usage = max_power_usage * (power_setting/100)
+	power_rating = max_power_rating * (power_setting/100)
 
 //dismantling code. copied from autolathe
 /obj/machinery/atmospherics/unary/freezer/attackby(var/obj/item/O as obj, var/mob/user as mob)

code/ATMOSPHERICS/components/unary/heat_source.dm

@@ -14,12 +14,10 @@
 	var/max_temperature = T20C + 680
 	var/internal_volume = 600	//L
 
-	var/on = 0
 	use_power = 0
 	idle_power_usage = 5			//5 Watts for thermostat related circuitry
-	active_power_usage 			//50 kW. The power rating of the heater
 
-	var/max_power_usage = 20000	//power rating when the usage is turned up to 100
+	var/max_power_rating = 20000	//power rating when the usage is turned up to 100
 	var/power_setting = 100
 
 	var/heating = 0		//mainly for icon updates
@@ -36,7 +34,7 @@
 	component_parts += new /obj/item/weapon/stock_parts/capacitor(src)
 	component_parts += new /obj/item/weapon/stock_parts/capacitor(src)
 
-	active_power_usage = max_power_usage * (power_setting/100)
+	power_rating = max_power_rating * (power_setting/100)
 
 /obj/machinery/atmospherics/unary/heater/initialize()
 	if(node) return
@@ -53,7 +51,7 @@
 
 /obj/machinery/atmospherics/unary/heater/update_icon()
 	if(src.node)
-		if(src.on && src.heating)
+		if(src.use_power && src.heating)
 			icon_state = "heater_1"
 		else
 			icon_state = "heater"
@@ -65,21 +63,19 @@
 /obj/machinery/atmospherics/unary/heater/process()
 	..()
 
-	if(stat & (NOPOWER|BROKEN) || !on)
+	if(stat & (NOPOWER|BROKEN) || !use_power)
 		heating = 0
-		update_use_power(0)
 		update_icon()
 		return
 
 	if (network && air_contents.total_moles && air_contents.temperature < set_temperature)
-		update_use_power(2)
-		air_contents.add_thermal_energy(active_power_usage * HEATER_PERF_MULT)
+		air_contents.add_thermal_energy(power_rating * HEATER_PERF_MULT)
+		use_power(power_rating)
 
 		heating = 1
 		network.update = 1
 	else
 		heating = 0
-		update_use_power(1)
 
 	update_icon()
 
@@ -92,7 +88,7 @@
 /obj/machinery/atmospherics/unary/heater/ui_interact(mob/user, ui_key = "main", var/datum/nanoui/ui = null, var/force_open = 1)
 	// this is the data which will be sent to the ui
 	var/data[0]
-	data["on"] = on ? 1 : 0
+	data["on"] = use_power ? 1 : 0
 	data["gasPressure"] = round(air_contents.return_pressure())
 	data["gasTemperature"] = round(air_contents.temperature)
 	data["minGasTemperature"] = 0
@@ -120,8 +116,7 @@
 
 /obj/machinery/atmospherics/unary/heater/Topic(href, href_list)
 	if (href_list["toggleStatus"])
-		src.on = !src.on
-		update_use_power(on)
+		src.use_power = !src.use_power
 		update_icon()
 	if(href_list["temp"])
 		var/amount = text2num(href_list["temp"])
@@ -154,14 +149,14 @@
 	cap_rating /= cap_count
 	bin_rating /= bin_count
 
-	max_power_usage = initial(max_power_usage)*cap_rating
+	max_power_rating = initial(max_power_rating)*cap_rating
 	max_temperature = max(initial(max_temperature) - T20C, 0)*((bin_rating*2 + cap_rating)/3) + T20C
 	air_contents.volume = max(initial(internal_volume) - 200, 0) + 200*bin_rating
 	set_power_level(power_setting)
 
 /obj/machinery/atmospherics/unary/heater/proc/set_power_level(var/new_power_setting)
 	power_setting = new_power_setting
-	active_power_usage = max_power_usage * (power_setting/100)
+	power_rating = max_power_rating * (power_setting/100)
 
 //dismantling code. copied from autolathe
 /obj/machinery/atmospherics/unary/heater/attackby(var/obj/item/O as obj, var/mob/user as mob)

code/ATMOSPHERICS/components/unary/outlet_injector.dm

@@ -5,17 +5,15 @@
 /obj/machinery/atmospherics/unary/outlet_injector
 	icon = 'icons/atmos/injector.dmi'
 	icon_state = "map_injector"
-	use_power = 1
 	layer = 3
 
 	name = "air injector"
 	desc = "Passively injects air into its surroundings. Has a valve attached to it that can control flow rate."
 
-	use_power = 1
+	use_power = 0
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 15000	//This also doubles as a measure of how powerful the pump is, in Watts. 15000 W ~ 20 HP
+	power_rating = 15000	//15000 W ~ 20 HP
 	
-	var/on = 0
 	var/injecting = 0
 
 	var/volume_rate = 50	//flow rate limit
@@ -34,7 +32,7 @@
 	if(!powered())
 		icon_state = "off"
 	else
-		icon_state = "[on ? "on" : "off"]"
+		icon_state = "[use_power ? "on" : "off"]"
 
 /obj/machinery/atmospherics/unary/outlet_injector/update_underlays()
 	if(..())
@@ -52,11 +50,11 @@
 
 /obj/machinery/atmospherics/unary/outlet_injector/process()
 	..()
-	injecting = 0
 
-	if((stat & (NOPOWER|BROKEN)) || !on)
-		update_use_power(0)	//usually we get here because a player turned a pump off - definitely want to update.
-		last_flow_rate = 0
+	last_power_draw = 0
+	last_flow_rate = 0
+
+	if((stat & (NOPOWER|BROKEN)) || !use_power)
 		return
 	
 	var/power_draw = -1
@@ -64,14 +62,11 @@
 	
 	if(environment && air_contents.temperature > 0)
 		var/transfer_moles = (volume_rate/air_contents.volume)*air_contents.total_moles //apply flow rate limit
-		power_draw = pump_gas(src, air_contents, environment, transfer_moles, active_power_usage)
+		power_draw = pump_gas(src, air_contents, environment, transfer_moles, power_rating)
 	
-	if (power_draw < 0)
-		//update_use_power(0)
-		use_power = 0	//don't force update - easier on CPU
-		last_flow_rate = 0
-	else
-		handle_power_draw(power_draw)
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
 		
 		if(network)
 			network.update = 1
@@ -79,7 +74,7 @@
 	return 1
 
 /obj/machinery/atmospherics/unary/outlet_injector/proc/inject()
-	if(on || injecting || (stat & NOPOWER))
+	if(injecting || (stat & NOPOWER))
 		return 0
 
 	var/datum/gas_mixture/environment = loc.return_air()
@@ -89,7 +84,7 @@
 	injecting = 1
 
 	if(air_contents.temperature > 0)
-		var/power_used = pump_gas(src, air_contents, environment, air_contents.total_moles, active_power_usage)
+		var/power_used = pump_gas(src, air_contents, environment, air_contents.total_moles, power_rating)
 		use_power(power_used)
 
 		if(network)
@@ -114,7 +109,7 @@
 	signal.data = list(
 		"tag" = id,
 		"device" = "AO",
-		"power" = on,
+		"power" = use_power,
 		"volume_rate" = volume_rate,
 		"sigtype" = "status"
 	 )
@@ -133,12 +128,10 @@
 		return 0
 
 	if(signal.data["power"])
-		on = text2num(signal.data["power"])
-		update_use_power(on)
+		use_power = text2num(signal.data["power"])
 
 	if(signal.data["power_toggle"])
-		on = !on
-		update_use_power(on)
+		use_power = !use_power
 
 	if(signal.data["inject"])
 		spawn inject()

code/ATMOSPHERICS/components/unary/vent_pump.dm

@@ -15,9 +15,9 @@
 
 	name = "Air Vent"
 	desc = "Has a valve and pump attached to it"
-	use_power = 1
+	use_power = 0
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 7500	//This also doubles as a measure of how powerful the pump is, in Watts. 7500 W ~ 10 HP
+	power_rating = 7500			//7500 W ~ 10 HP
 
 	connect_types = CONNECT_TYPE_REGULAR|CONNECT_TYPE_SUPPLY //connects to regular and supply pipes
 
@@ -26,11 +26,8 @@
 	var/area_uid
 	var/id_tag = null
 
-	var/on = 0
 	var/pump_direction = 1 //0 = siphoning, 1 = releasing
 
-	var/last_power_draw = 0
-
 	var/external_pressure_bound = EXTERNAL_PRESSURE_BOUND
 	var/internal_pressure_bound = INTERNAL_PRESSURE_BOUND
 
@@ -53,14 +50,14 @@
 	var/radio_filter_in
 
 /obj/machinery/atmospherics/unary/vent_pump/on
-	on = 1
+	use_power = 1
 	icon_state = "map_vent_out"
 
 /obj/machinery/atmospherics/unary/vent_pump/siphon
 	pump_direction = 0
 
 /obj/machinery/atmospherics/unary/vent_pump/siphon/on
-	on = 1
+	use_power = 1
 	icon_state = "map_vent_in"
 
 /obj/machinery/atmospherics/unary/vent_pump/New()
@@ -82,7 +79,7 @@
 /obj/machinery/atmospherics/unary/vent_pump/high_volume
 	name = "Large Air Vent"
 	power_channel = EQUIP
-	active_power_usage = 15000	//15 kW ~ 20 HP
+	power_rating = 15000	//15 kW ~ 20 HP
 
 /obj/machinery/atmospherics/unary/vent_pump/high_volume/New()
 	..()
@@ -91,7 +88,7 @@
 /obj/machinery/atmospherics/unary/vent_pump/engine
 	name = "Engine Core Vent"
 	power_channel = ENVIRON
-	active_power_usage = 15000	//15 kW ~ 20 HP
+	power_rating = 15000	//15 kW ~ 20 HP
 
 /obj/machinery/atmospherics/unary/vent_pump/engine/New()
 	..()
@@ -101,7 +98,7 @@
 	if(!check_icon_cache())
 		return
 	if (!node)
-		on = 0
+		use_power = 0
 
 	overlays.Cut()
 
@@ -119,7 +116,7 @@
 	else if(!powered())
 		vent_icon += "off"
 	else
-		vent_icon += "[on ? "[pump_direction ? "out" : "in"]" : "off"]"
+		vent_icon += "[use_power ? "[pump_direction ? "out" : "in"]" : "off"]"
 
 	overlays += icon_manager.get_atmos_icon("device", , , vent_icon)
 
@@ -144,7 +141,7 @@
 /obj/machinery/atmospherics/unary/vent_pump/proc/can_pump()
 	if(stat & (NOPOWER|BROKEN))
 		return 0
-	if(!on)
+	if(!use_power)
 		return 0
 	if(welded)
 		return 0
@@ -153,12 +150,12 @@
 /obj/machinery/atmospherics/unary/vent_pump/process()
 	..()
 
+	last_power_draw = 0
+	last_flow_rate = 0
+
 	if (!node)
-		on = 0
+		use_power = 0
 	if(!can_pump())
-		update_use_power(0)	//usually we get here because a player turned a pump off - definitely want to update.
-		last_power_draw = 0
-		last_flow_rate = 0
 		return 0
 
 	var/datum/gas_mixture/environment = loc.return_air()
@@ -171,29 +168,18 @@
 
 	if((environment.temperature || air_contents.temperature) && pressure_delta > 0.5)
 		if(pump_direction) //internal -> external
-			var/output_volume = environment.volume * environment.group_multiplier
-			var/air_temperature = environment.temperature? environment.temperature : air_contents.temperature
-			var/transfer_moles = pressure_delta*output_volume/(air_temperature * R_IDEAL_GAS_EQUATION)
-			//src.visible_message("DEBUG >>> [src]: output_volume = [output_volume]L; air_temperature = [air_temperature]K; transfer_moles = [transfer_moles] mol")
-
-			power_draw = pump_gas(src, air_contents, environment, transfer_moles, active_power_usage)
+			var/transfer_moles = calculate_transfer_moles(air_contents, environment)
+			power_draw = pump_gas(src, air_contents, environment, transfer_moles, power_rating)
 		else //external -> internal
-			var/output_volume = air_contents.volume + (network? network.volume : 0)
-			var/air_temperature = air_contents.temperature? air_contents.temperature : environment.temperature
-			var/transfer_moles = pressure_delta*output_volume/(air_temperature * R_IDEAL_GAS_EQUATION)
+			var/transfer_moles = calculate_transfer_moles(environment, air_contents, (network)? network.volume : 0)
 
 			//limit flow rate from turfs
 			transfer_moles = min(transfer_moles, environment.total_moles*air_contents.volume/environment.volume)	//group_multiplier gets divided out here
+			power_draw = pump_gas(src, environment, air_contents, transfer_moles, power_rating)
 
-			power_draw = pump_gas(src, environment, air_contents, transfer_moles, active_power_usage)
-
-	if (power_draw < 0)
-		last_power_draw = 0
-		last_flow_rate = 0
-		//update_use_power(0)
-		use_power = 0	//don't force update - easier on CPU
-	else
-		last_power_draw = handle_power_draw(power_draw)
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
 		if(network)
 			network.update = 1
 
@@ -236,7 +222,7 @@
 		"area" = src.area_uid,
 		"tag" = src.id_tag,
 		"device" = "AVP",
-		"power" = on,
+		"power" = use_power,
 		"direction" = pump_direction?("release"):("siphon"),
 		"checks" = pressure_checks,
 		"internal" = internal_pressure_bound,
@@ -283,10 +269,10 @@
 		pump_direction = 1
 
 	if(signal.data["power"] != null)
-		on = text2num(signal.data["power"])
+		use_power = text2num(signal.data["power"])
 
 	if(signal.data["power_toggle"] != null)
-		on = !on
+		use_power = !use_power
 
 	if(signal.data["checks"] != null)
 		if (signal.data["checks"] == "default")
@@ -392,7 +378,7 @@
 /obj/machinery/atmospherics/unary/vent_pump/attackby(var/obj/item/weapon/W as obj, var/mob/user as mob)
 	if (!istype(W, /obj/item/weapon/wrench))
 		return ..()
-	if (!(stat & NOPOWER) && on)
+	if (!(stat & NOPOWER) && use_power)
 		user << "\red You cannot unwrench this [src], turn it off first."
 		return 1
 	var/turf/T = src.loc

code/ATMOSPHERICS/components/unary/vent_scrubber.dm

@@ -4,10 +4,9 @@
 
 	name = "Air Scrubber"
 	desc = "Has a valve and pump attached to it"
-	use_power = 1
+	use_power = 0
 	idle_power_usage = 150		//internal circuitry, friction losses and stuff
-	active_power_usage = 7500	//This also doubles as a measure of how powerful the pump is, in Watts. 7500 W ~ 10 HP
-	var/last_power_draw = 0
+	power_rating = 7500			//7500 W ~ 10 HP
 
 	connect_types = CONNECT_TYPE_REGULAR|CONNECT_TYPE_SCRUBBER //connects to regular and scrubber pipes
 
@@ -18,7 +17,6 @@
 	var/frequency = 1439
 	var/datum/radio_frequency/radio_connection
 
-	var/on = 0
 	var/scrubbing = 1 //0 = siphoning, 1 = scrubbing
 	var/list/scrubbing_gas = list("carbon_dioxide")
 
@@ -29,7 +27,7 @@
 	var/radio_filter_in
 
 /obj/machinery/atmospherics/unary/vent_scrubber/on
-	on = 1
+	use_power = 1
 	icon_state = "map_scrubber_on"
 
 /obj/machinery/atmospherics/unary/vent_scrubber/New()
@@ -63,7 +61,7 @@
 	if(!powered())
 		scrubber_icon += "off"
 	else
-		scrubber_icon += "[on ? "[scrubbing ? "on" : "in"]" : "off"]"
+		scrubber_icon += "[use_power ? "[scrubbing ? "on" : "in"]" : "off"]"
 
 	overlays += icon_manager.get_atmos_icon("device", , , scrubber_icon)
 
@@ -98,7 +96,7 @@
 		"tag" = id_tag,
 		"device" = "AScr",
 		"timestamp" = world.time,
-		"power" = on,
+		"power" = use_power,
 		"scrubbing" = scrubbing,
 		"panic" = panic,
 		"filter_co2" = ("carbon_dioxide" in scrubbing_gas),
@@ -124,13 +122,14 @@
 
 /obj/machinery/atmospherics/unary/vent_scrubber/process()
 	..()
+
+	last_power_draw = 0
+	last_flow_rate = 0
+
 	if (!node)
-		on = 0
+		use_power = 0
 	//broadcast_status()
-	if(!on || (stat & (NOPOWER|BROKEN)))
-		update_use_power(0)	//we got here because a player turned a pump off - definitely want to update.
-		last_flow_rate = 0
-		last_power_draw = 0
+	if(!use_power || (stat & (NOPOWER|BROKEN)))
 		return 0
 
 	var/datum/gas_mixture/environment = loc.return_air()
@@ -140,20 +139,16 @@
 		//limit flow rate from turfs
 		var/transfer_moles = min(environment.total_moles, environment.total_moles*MAX_SCRUBBER_FLOWRATE/environment.volume)	//group_multiplier gets divided out here
 
-		power_draw = scrub_gas(src, scrubbing_gas, environment, air_contents, transfer_moles, active_power_usage)
+		power_draw = scrub_gas(src, scrubbing_gas, environment, air_contents, transfer_moles, power_rating)
 	else //Just siphon all air
 		//limit flow rate from turfs
 		var/transfer_moles = min(environment.total_moles, environment.total_moles*MAX_SIPHON_FLOWRATE/environment.volume)	//group_multiplier gets divided out here
 
-		power_draw = pump_gas(src, environment, air_contents, transfer_moles, active_power_usage)
+		power_draw = pump_gas(src, environment, air_contents, transfer_moles, power_rating)
 
-	if (power_draw < 0)
-		//update_use_power(0)
-		use_power = 0	//don't force update. Sure, we will continue to use power even though we're not pumping anything, but it is easier on the CPU
-		last_power_draw = 0
-		last_flow_rate = 0
-	else
-		last_power_draw = handle_power_draw(power_draw)
+	if (power_draw >= 0)
+		last_power_draw = power_draw
+		use_power(power_draw)
 
 	if(network)
 		network.update = 1
@@ -171,21 +166,21 @@
 		return 0
 
 	if(signal.data["power"] != null)
-		on = text2num(signal.data["power"])
+		use_power = text2num(signal.data["power"])
 	if(signal.data["power_toggle"] != null)
-		on = !on
+		use_power = !use_power
 
 	if(signal.data["panic_siphon"]) //must be before if("scrubbing" thing
 		panic = text2num(signal.data["panic_siphon"] != null)
 		if(panic)
-			on = 1
+			use_power = 1
 			scrubbing = 0
 		else
 			scrubbing = 1
 	if(signal.data["toggle_panic_siphon"] != null)
 		panic = !panic
 		if(panic)
-			on = 1
+			use_power = 1
 			scrubbing = 0
 		else
 			scrubbing = 1
@@ -238,7 +233,7 @@
 /obj/machinery/atmospherics/unary/vent_scrubber/attackby(var/obj/item/weapon/W as obj, var/mob/user as mob)
 	if (!istype(W, /obj/item/weapon/wrench))
 		return ..()
-	if (!(stat & NOPOWER) && on)
+	if (!(stat & NOPOWER) && use_power)
 		user << "\red You cannot unwrench this [src], turn it off first."
 		return 1
 	var/turf/T = src.loc