Starting a Reef in Phoenix AZ Heat

[Ag NSX]

I lived in Chicago with my last reef tank. Now I live in Scottsdale, AZ and am thinking of a reef tank again.

My biggest issue here is the heat during the summer. It's not uncommon for people to have a $300 electric bill in the summer months. I keep my home at 80 degrees in the summer, so I'm wondering what my electric will be like after adding a reef tank.

2 things concern me.
1) the additional heat output of MH into my home.
2) the need to chill the tank water

Luckily, the house I just moved into has a little 6x4 room in the corner which I have no idea what it could be used for, other than for an equipment room.

So I'm thinking about massively insulating it on the inside and then putting a sump in there and keep that room alot colder than the rest of the home. I would also channel the MH light vents into that room also.

What do you think?

[Future]

I'd check to see how old the current insulation is up in the attic as well as how thick it is. The roof takes most of the heat, so technically that IS the hottest area in the house. Next you'll want to see what side of the house get's the least sun exposure.

The MH won't place a lot of heat into the house, but it will place heat into the tank. Some people are able to offset that with chillers other with surface fans.

IMO, if you're going to blow some cash on the cooling, I'd start with the proper typical house insulation and ventalation, otherwise you'll just end up fighting a battle you're going to pay for anyway.
I went through that 6 years ago in a place I was renting. The insulation was 10+ years old and even with a fan running the temp in the tank was upwards of 84*. Landlord put in new insulation (finally) and tank temp decreased to 78*. (I used basic flo. lights at the time, imagine had I used MH)

[Ninong]

How large a reef tank are you talking about? Are you thinking of a 120-gal tank or a 300-gal tank? That makes a big difference.

You might want to consider HO T5 lighting instead of metal halides if heat is an issue. If you're thinking of 400w metal halides, then you will definitely have a lot of heat to deal with.

You will almost certainly have to run a chiller because even if you keep the house at 75 degrees Fahrenheit, the heat from the pumps and the lighting will bring your water's temperature up above 83 degrees, even with ventilation fans.

How much are you paying in Scottsdale per kilowatt hour, including any surcharges for fuel adjustments? Our cost down here varies tremendously because the fuel adjustment varies a lot. Sometimes the fuel adjustment per kilowatt hour is higher than the basic charge per kilowatt hour. And then we have a 9.99% hurricane recovery surcharge added at the end of the bill.