Solar Hot Water, commercial grade!

[UncleTwisty]

Hey All,

Pardon my ignorance on all aspects of solar heating, as I'm new to this.

Basically I've been put in charge of a solar project for my boss.

He owns an old warehouse that he has converted into apartments and art studios.

My project consists of two parts.

Part A) Solar heating for hot water and radiator heating systems in the building of which has about 40 people.

Part B) Solar heating for a 2000 ga swim spa (or more realistically: awesome 20 person hot tub)

From what research I've done I've come to conclude that the system would rely on evacuated tube collectors, but I'm not sure where to find the equations to figure out what size I need or how many.

Other questions include:
for Part A) Would a storage tank be useful to store hot water in the loop? (That could also pertain to part B as well)

Water or Glycol in a project of this magnitude?

Any help would be greatly appreciated.

As a side note, it's great to see that this community exists as this is a fascinating technology that makes so much sense in todays rising energy costs.

Thanks in advance,

Uncle twisty.

[AC_Hacker]

Originally Posted by UncleTwisty

Basically I've been put in charge of a solar project for my boss.

He owns an old warehouse that he has converted into apartments and art studios.

My project consists of two parts.

Part A) Solar heating for hot water and radiator heating systems in the building of which has about 40 people.

Part B) Solar heating for a 2000 ga swim spa (or more realistically: awesome 20 person hot tub)

Wow, better get used to the idea that you're going to be burning a huge amount of midnight oil.

You need to find out what is the heat load is of your building. This will be calculated under 'design conditions', which means how cold does it get on the coldest 2% of the year.

Then you will need to get or buy a program that asks you questions about area of floor, walls roof, windows and insulation, etc. since these factors will determine your heat loss. The program will crunch the numbers for you. The heat load will be in BTU/hr.

If you have records of how much heating your present system put out during the coldest month or better yet, week... this should also be in BTU/hr, and you can use it as a check so that you know that you are in the ball bark.

You are also going to need to know how much energy, in BTU/hr it's going to take to keep the swimming pool heated. This will be part of your heat load.

After all this, you are standing at the very beginning of a long journey.

I hope you really enjoy challenges, because you definitely have one on your hands.

* * *

You know, with your reputation and job on the line, and the comfort and happiness of many people (and their lawyers, too), you might want to consider hiring a professional for something this big.

DIY definitely has its place, and so does CYA.

Best,

-AC_Hacker