We're building a new house (I'm the homeowner) that is about 6500 finished sqft (including a finished basement) that will have 4 full baths, 2 half baths, a kitchen and kitchenette. I'm trying to figure out the right thermostatic mixing valve and volume control valve we need for our showers (3/4" vs 1/2"). We like our water pressure, so all of our shower heads will be 2.5gpm. This is the rest of our set up:
Two tankless water heaters for the whole house
Primary suite walk-in shower: Kohler wall mounted rainhead and a halndheld. Two sets of the Kohler MasterShower temperature control valve trim and the Kohler MasterShower volume control valve trim (one for the rainhead, and one for the handheld so that the handheld can be a different temperature than the rainhead).
Kids' showers (2 of the 4 showers in the house): One wall mounted shower head and one handheld. One MasterShower temperature control valve trim, MasterShower volume control valve trim, and MasterShower transfer valve trim with the K-728-K 3/4" two- or three-way transfer valve (if I'm understanding correctly, this transfer valve allows us to have the handheld and main shower head on at the same time?).
Guest shower: Handheld shower head with 2.5 gpm. Rite-Temp valve trim with K-8304 Series Rite-Temp` Valve
So I'm just confused on which thermostatic mixing valves and volume control valves we need for our primary shower and our kids' showers. 1/2" or 3/4"? I'm understanding from reading other threads on this forum that 3/4" helps with better water pressure which we like, but also read that with tankless water heaters, we might need 1/2"? And I guess the other related question is: are two tankless water heaters sufficient for this set up?
Two tankless water heaters for the whole house
Primary suite walk-in shower: Kohler wall mounted rainhead and a halndheld. Two sets of the Kohler MasterShower temperature control valve trim and the Kohler MasterShower volume control valve trim (one for the rainhead, and one for the handheld so that the handheld can be a different temperature than the rainhead).
Kids' showers (2 of the 4 showers in the house): One wall mounted shower head and one handheld. One MasterShower temperature control valve trim, MasterShower volume control valve trim, and MasterShower transfer valve trim with the K-728-K 3/4" two- or three-way transfer valve (if I'm understanding correctly, this transfer valve allows us to have the handheld and main shower head on at the same time?).
Guest shower: Handheld shower head with 2.5 gpm. Rite-Temp valve trim with K-8304 Series Rite-Temp` Valve
So I'm just confused on which thermostatic mixing valves and volume control valves we need for our primary shower and our kids' showers. 1/2" or 3/4"? I'm understanding from reading other threads on this forum that 3/4" helps with better water pressure which we like, but also read that with tankless water heaters, we might need 1/2"? And I guess the other related question is: are two tankless water heaters sufficient for this set up?
